Per destination latest image tag

We tag the deployed image with the latest image tag when deploying. But if we are deploying multiple destinations to the same host they'll conflict with each other.
2024-03-27 09:43:21 +00:00
145 changed files with 1330 additions and 4396 deletions
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -3,7 +3,6 @@ on:
  push:
    branches:
      - main
-      - 1-8-stable
  pull_request:
 jobs:
  rubocop:
@@ -25,12 +24,25 @@ jobs:
    strategy:
      matrix:
        ruby-version:
+          - "2.7"
          - "3.1"
          - "3.2"
          - "3.3"
        gemfile:
          - Gemfile
+          - gemfiles/ruby_2.7.gemfile
          - gemfiles/rails_edge.gemfile
+        exclude:
+          - ruby-version: "2.7"
+            gemfile: Gemfile
+          - ruby-version: "2.7"
+            gemfile: gemfiles/rails_edge.gemfile
+          - ruby-version: "3.1"
+            gemfile: gemfiles/ruby_2.7.gemfile
+          - ruby-version: "3.2"
+            gemfile: gemfiles/ruby_2.7.gemfile
+          - ruby-version: "3.3"
+            gemfile: gemfiles/ruby_2.7.gemfile
    name: ${{ format('Tests (Ruby {0})', matrix.ruby-version) }}
    runs-on: ubuntu-latest
    continue-on-error: true
--- a/4
+++ b/4
@@ -1,7 +1,7 @@
 # Use the official Ruby 3.2.0 Alpine image as the base image
 FROM ruby:3.2.0-alpine

-# Install docker/buildx-bin
+# Install  docker/buildx-bin
 COPY --from=docker/buildx-bin /buildx /usr/libexec/docker/cli-plugins/docker-buildx

 # Set the working directory to /kamal
@@ -14,7 +14,7 @@ COPY Gemfile Gemfile.lock kamal.gemspec ./
 COPY lib/kamal/version.rb /kamal/lib/kamal/version.rb

 # Install system dependencies
-RUN apk add --no-cache build-base git docker openrc openssh-client-default \
+RUN apk add --no-cache --update build-base git docker openrc openssh-client-default \
    && rc-update add docker boot \
    && gem install bundler --version=2.4.3 \
    && bundle install
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
  remote: .
  specs:
-    kamal (1.9.0)
+    kamal (1.4.0)
      activesupport (>= 7.0)
      base64 (~> 0.2)
      bcrypt_pbkdf (~> 1.0)
@@ -9,7 +9,7 @@ PATH
      dotenv (~> 2.8)
      ed25519 (~> 1.2)
      net-ssh (~> 7.0)
-      sshkit (>= 1.23.0, < 2.0)
+      sshkit (~> 1.21)
      thor (~> 1.2)
      zeitwerk (~> 2.5)

@@ -75,8 +75,6 @@ GEM
    mutex_m (0.2.0)
    net-scp (4.0.0)
      net-ssh (>= 2.6.5, < 8.0.0)
-    net-sftp (4.0.0)
-      net-ssh (>= 5.0.0, < 8.0.0)
    net-ssh (7.2.1)
    nokogiri (1.16.0-arm64-darwin)
      racc (~> 1.4)
@@ -153,10 +151,9 @@ GEM
      rubocop-rails
    ruby-progressbar (1.13.0)
    ruby2_keywords (0.0.5)
-    sshkit (1.23.0)
-      base64
+    sshkit (1.21.7)
+      mutex_m
      net-scp (>= 1.1.2)
-      net-sftp (>= 2.1.2)
      net-ssh (>= 2.8.0)
    stringio (3.1.0)
    thor (1.3.0)
--- a/bin/docs
+++ b/bin/docs
@@ -1,134 +0,0 @@
-#!/usr/bin/env ruby
-require "stringio"
-
-def usage
-  puts "Usage: #{$0} <kamal_site_repo>"
-  exit 1
-end
-
-usage if ARGV.size != 1
-
-kamal_site_repo = ARGV[0]
-
-if !File.directory?(kamal_site_repo)
-  puts "Error: #{kamal_site_repo} is not a directory"
-  exit 1
-end
-
-DOCS = {
-  "accessory" => "Accessories",
-  "boot" => "Booting",
-  "builder" => "Builders",
-  "configuration" => "Configuration overview",
-  "env" => "Environment variables",
-  "healthcheck" => "Healthchecks",
-  "logging" => "Logging",
-  "registry" => "Docker Registry",
-  "role" => "Roles",
-  "servers" => "Servers",
-  "ssh" => "SSH",
-  "sshkit" => "SSHKit",
-  "traefik" => "Traefik"
-}
-
-class DocWriter
-  attr_reader :from_file, :to_file, :key, :heading, :body, :output, :in_yaml
-
-  def initialize(from_file, to_dir)
-    @from_file = from_file
-    @key = File.basename(from_file, ".yml")
-    @to_file = File.join(to_dir, "#{linkify(DOCS[key])}.md")
-    @body = File.readlines(from_file)
-    @heading = body.shift.chomp("\n")
-    @output = nil
-  end
-
-  def write
-    puts "Writing #{to_file}"
-    generate_markdown
-    File.write(to_file, output.string)
-  end
-
-  private
-    def generate_markdown
-      @output = StringIO.new
-
-      generate_header
-
-      place = :in_section
-
-      loop do
-        line = body.shift&.chomp("\n")
-        break if line.nil?
-
-        case place
-        when :new_section, :in_section
-          if line.empty?
-            output.puts
-            place = :new_section
-          elsif line =~ /^ *#/
-            generate_line(line, place: place)
-            place = :in_section
-          else
-            output.puts "```yaml"
-            output.print line
-            place = :in_yaml
-          end
-        when :in_yaml
-          if line =~ /^ *#/
-            output.puts "```"
-            generate_line(line, place: :new_section)
-            place = :in_section
-          else
-            output.puts
-            output.print line
-          end
-        end
-      end
-
-      output.puts "\n```" if place == :in_yaml
-    end
-
-    def generate_header
-      output.puts "---"
-      output.puts "title: #{heading[2..-1]}"
-      output.puts "---"
-      output.puts
-      output.puts heading
-      output.puts
-    end
-
-    def generate_line(line, place: :in_section)
-      line = line.gsub(/^ *#\s?/, "")
-
-      if line =~ /(.*)kamal docs ([a-z]*)(.*)/
-        line = "#{$1}[#{DOCS[$2]}](../#{linkify(DOCS[$2])})#{$3}"
-      end
-
-      if line =~ /(.*)https:\/\/kamal-deploy.org([a-z\/-]*)(.*)/
-        line = "#{$1}[#{titlify($2.split("/").last)}](#{$2})#{$3}"
-      end
-
-      if place == :new_section
-        output.puts "## [#{line}](##{linkify(line)})"
-      else
-        output.puts line
-      end
-    end
-
-    def linkify(text)
-      text.downcase.gsub(" ", "-")
-    end
-
-    def titlify(text)
-      text.capitalize.gsub("-", " ")
-    end
-end
-
-from_dir = File.join(File.dirname(__FILE__), "../lib/kamal/configuration/docs")
-to_dir = File.join(kamal_site_repo, "docs/configuration")
-Dir.glob("#{from_dir}/*") do |from_file|
-  key = File.basename(from_file, ".yml")
-
-  DocWriter.new(from_file, to_dir).write
-end
--- a/gemfiles/ruby_2.7.gemfile
+++ b/gemfiles/ruby_2.7.gemfile
@@ -0,0 +1,6 @@
+source 'https://rubygems.org'
+git_source(:github) { |repo| "https://github.com/#{repo}.git" }
+
+gemspec path: "../"
+
+gem "nokogiri", "~> 1.15.0"
--- a/kamal.gemspec
+++ b/kamal.gemspec
@@ -12,7 +12,7 @@ Gem::Specification.new do |spec|
  spec.executables = %w[ kamal ]

  spec.add_dependency "activesupport", ">= 7.0"
-  spec.add_dependency "sshkit", ">= 1.23.0", "< 2.0"
+  spec.add_dependency "sshkit", "~> 1.21"
  spec.add_dependency "net-ssh", "~> 7.0"
  spec.add_dependency "thor", "~> 1.2"
  spec.add_dependency "dotenv", "~> 2.8"
--- a/lib/kamal.rb
+++ b/lib/kamal.rb
@@ -1,12 +1,10 @@
 module Kamal
-  class ConfigurationError < StandardError; end
 end

 require "active_support"
 require "zeitwerk"
-require "yaml"

 loader = Zeitwerk::Loader.for_gem
-loader.ignore(File.join(__dir__, "kamal", "sshkit_with_ext.rb"))
+loader.ignore("#{__dir__}/kamal/sshkit_with_ext.rb")
 loader.setup
 loader.eager_load # We need all commands loaded.
--- a/lib/kamal/cli.rb
+++ b/lib/kamal/cli.rb
@@ -1,6 +1,6 @@
 module Kamal::Cli
-  class HookError < StandardError; end
  class LockError < StandardError; end
+  class HookError < StandardError; end
 end

 # SSHKit uses instance eval, so we need a global const for ergonomics
--- a/lib/kamal/cli/accessory.rb
+++ b/lib/kamal/cli/accessory.rb
@@ -1,7 +1,7 @@
 class Kamal::Cli::Accessory < Kamal::Cli::Base
  desc "boot [NAME]", "Boot new accessory service on host (use NAME=all to boot all accessories)"
  def boot(name, login: true)
-    with_lock do
+    mutating do
      if name == "all"
        KAMAL.accessory_names.each { |accessory_name| boot(accessory_name) }
      else
@@ -21,7 +21,7 @@ class Kamal::Cli::Accessory < Kamal::Cli::Base

  desc "upload [NAME]", "Upload accessory files to host", hide: true
  def upload(name)
-    with_lock do
+    mutating do
      with_accessory(name) do |accessory, hosts|
        on(hosts) do
          accessory.files.each do |(local, remote)|
@@ -38,7 +38,7 @@ class Kamal::Cli::Accessory < Kamal::Cli::Base

  desc "directories [NAME]", "Create accessory directories on host", hide: true
  def directories(name)
-    with_lock do
+    mutating do
      with_accessory(name) do |accessory, hosts|
        on(hosts) do
          accessory.directories.keys.each do |host_path|
@@ -51,7 +51,7 @@ class Kamal::Cli::Accessory < Kamal::Cli::Base

  desc "reboot [NAME]", "Reboot existing accessory on host (stop container, remove container, start new container; use NAME=all to boot all accessories)"
  def reboot(name)
-    with_lock do
+    mutating do
      if name == "all"
        KAMAL.accessory_names.each { |accessory_name| reboot(accessory_name) }
      else
@@ -70,7 +70,7 @@ class Kamal::Cli::Accessory < Kamal::Cli::Base

  desc "start [NAME]", "Start existing accessory container on host"
  def start(name)
-    with_lock do
+    mutating do
      with_accessory(name) do |accessory, hosts|
        on(hosts) do
          execute *KAMAL.auditor.record("Started #{name} accessory"), verbosity: :debug
@@ -82,7 +82,7 @@ class Kamal::Cli::Accessory < Kamal::Cli::Base

  desc "stop [NAME]", "Stop existing accessory container on host"
  def stop(name)
-    with_lock do
+    mutating do
      with_accessory(name) do |accessory, hosts|
        on(hosts) do
          execute *KAMAL.auditor.record("Stopped #{name} accessory"), verbosity: :debug
@@ -94,7 +94,7 @@ class Kamal::Cli::Accessory < Kamal::Cli::Base

  desc "restart [NAME]", "Restart existing accessory container on host"
  def restart(name)
-    with_lock do
+    mutating do
      with_accessory(name) do
        stop(name)
        start(name)
@@ -107,9 +107,8 @@ class Kamal::Cli::Accessory < Kamal::Cli::Base
    if name == "all"
      KAMAL.accessory_names.each { |accessory_name| details(accessory_name) }
    else
-      type = "Accessory #{name}"
      with_accessory(name) do |accessory, hosts|
-        on(hosts) { puts_by_host host, capture_with_info(*accessory.info), type: type }
+        on(hosts) { puts capture_with_info(*accessory.info) }
      end
    end
  end
@@ -149,25 +148,23 @@ class Kamal::Cli::Accessory < Kamal::Cli::Base
  option :since, aliases: "-s", desc: "Show logs since timestamp (e.g. 2013-01-02T13:23:37Z) or relative (e.g. 42m for 42 minutes)"
  option :lines, type: :numeric, aliases: "-n", desc: "Number of log lines to pull from each server"
  option :grep, aliases: "-g", desc: "Show lines with grep match only (use this to fetch specific requests by id)"
-  option :grep_options, aliases: "-o", desc: "Additional options supplied to grep"
  option :follow, aliases: "-f", desc: "Follow logs on primary server (or specific host set by --hosts)"
  def logs(name)
    with_accessory(name) do |accessory, hosts|
      grep = options[:grep]
-      grep_options = options[:grep_options]

      if options[:follow]
        run_locally do
          info "Following logs on #{hosts}..."
-          info accessory.follow_logs(grep: grep, grep_options: grep_options)
-          exec accessory.follow_logs(grep: grep, grep_options: grep_options)
+          info accessory.follow_logs(grep: grep)
+          exec accessory.follow_logs(grep: grep)
        end
      else
        since = options[:since]
        lines = options[:lines].presence || ((since || grep) ? nil : 100) # Default to 100 lines if since or grep isn't set

        on(hosts) do
-          puts capture_with_info(*accessory.logs(since: since, lines: lines, grep: grep, grep_options: grep_options))
+          puts capture_with_info(*accessory.logs(since: since, lines: lines, grep: grep))
        end
      end
    end
@@ -176,12 +173,17 @@ class Kamal::Cli::Accessory < Kamal::Cli::Base
  desc "remove [NAME]", "Remove accessory container, image and data directory from host (use NAME=all to remove all accessories)"
  option :confirmed, aliases: "-y", type: :boolean, default: false, desc: "Proceed without confirmation question"
  def remove(name)
-    confirming "This will remove all containers, images and data directories for #{name}. Are you sure?" do
-      with_lock do
-        if name == "all"
-          KAMAL.accessory_names.each { |accessory_name| remove_accessory(accessory_name) }
-        else
-          remove_accessory(name)
+    mutating do
+      if name == "all"
+        KAMAL.accessory_names.each { |accessory_name| remove(accessory_name) }
+      else
+        confirming "This will remove all containers, images and data directories for #{name}. Are you sure?" do
+          with_accessory(name) do
+            stop(name)
+            remove_container(name)
+            remove_image(name)
+            remove_service_directory(name)
+          end
        end
      end
    end
@@ -189,7 +191,7 @@ class Kamal::Cli::Accessory < Kamal::Cli::Base

  desc "remove_container [NAME]", "Remove accessory container from host", hide: true
  def remove_container(name)
-    with_lock do
+    mutating do
      with_accessory(name) do |accessory, hosts|
        on(hosts) do
          execute *KAMAL.auditor.record("Remove #{name} accessory container"), verbosity: :debug
@@ -201,7 +203,7 @@ class Kamal::Cli::Accessory < Kamal::Cli::Base

  desc "remove_image [NAME]", "Remove accessory image from host", hide: true
  def remove_image(name)
-    with_lock do
+    mutating do
      with_accessory(name) do |accessory, hosts|
        on(hosts) do
          execute *KAMAL.auditor.record("Removed #{name} accessory image"), verbosity: :debug
@@ -213,7 +215,7 @@ class Kamal::Cli::Accessory < Kamal::Cli::Base

  desc "remove_service_directory [NAME]", "Remove accessory directory used for uploaded files and data directories from host", hide: true
  def remove_service_directory(name)
-    with_lock do
+    mutating do
      with_accessory(name) do |accessory, hosts|
        on(hosts) do
          execute *accessory.remove_service_directory
@@ -222,25 +224,6 @@ class Kamal::Cli::Accessory < Kamal::Cli::Base
    end
  end

-  desc "downgrade", "Downgrade accessories from Kamal 2 to 1.9"
-  option :rolling, type: :boolean, default: false, desc: "Upgrade one host at a time"
-  option :confirmed, aliases: "-y", type: :boolean, default: false, desc: "Proceed without confirmation question"
-  def downgrade(name)
-    confirming "This will restart all accessories" do
-      with_lock do
-        host_groups = options[:rolling] ? KAMAL.accessory_hosts : [ KAMAL.accessory_hosts ]
-        host_groups.each do |hosts|
-          host_list = Array(hosts).join(",")
-          KAMAL.with_specific_hosts(hosts) do
-            say "Downgrading #{name} accessories on #{host_list}...", :magenta
-            reboot name
-            say "Downgraded #{name} accessories on #{host_list}...", :magenta
-          end
-        end
-      end
-    end
-  end
-
  private
    def with_accessory(name)
      if KAMAL.config.accessory(name)
@@ -266,13 +249,4 @@ class Kamal::Cli::Accessory < Kamal::Cli::Base
        accessory.hosts
      end
    end
-
-    def remove_accessory(name)
-      with_accessory(name) do
-        stop(name)
-        remove_container(name)
-        remove_image(name)
-        remove_service_directory(name)
-      end
-    end
 end
--- a/lib/kamal/cli/app.rb
+++ b/lib/kamal/cli/app.rb
@@ -1,45 +1,41 @@
 class Kamal::Cli::App < Kamal::Cli::Base
  desc "boot", "Boot app on servers (or reboot app if already running)"
  def boot
-    with_lock do
-      say "Get most recent version available as an image...", :magenta unless options[:version]
-      using_version(version_or_latest) do |version|
-        say "Start container with version #{version} using a #{KAMAL.config.readiness_delay}s readiness delay (or reboot if already running)...", :magenta
+    mutating do
+      hold_lock_on_error do
+        say "Get most recent version available as an image...", :magenta unless options[:version]
+        using_version(version_or_latest) do |version|
+          say "Start container with version #{version} using a #{KAMAL.config.readiness_delay}s readiness delay (or reboot if already running)...", :magenta

-        # Assets are prepared in a separate step to ensure they are on all hosts before booting
-        on(KAMAL.hosts) do
-          KAMAL.roles_on(host).each do |role|
-            Kamal::Cli::App::PrepareAssets.new(host, role, self).run
+          # Assets are prepared in a separate step to ensure they are on all hosts before booting
+          on(KAMAL.hosts) do
+            execute *KAMAL.auditor.record("Tagging #{KAMAL.config.absolute_image} as the latest image"), verbosity: :debug
+            execute *KAMAL.app.tag_current_image_as_latest
+
+            KAMAL.roles_on(host).each do |role|
+              Kamal::Cli::App::PrepareAssets.new(host, role, self).run
+            end
          end
-        end

-        # Primary hosts and roles are returned first, so they can open the barrier
-        barrier = Kamal::Cli::Healthcheck::Barrier.new
-
-        on(KAMAL.hosts, **KAMAL.boot_strategy) do |host|
-          KAMAL.roles_on(host).each do |role|
-            Kamal::Cli::App::Boot.new(host, role, self, version, barrier).run
+          on(KAMAL.hosts, **KAMAL.boot_strategy) do |host|
+            KAMAL.roles_on(host).each do |role|
+              Kamal::Cli::App::Boot.new(host, role, version, self).run
+            end
          end
        end
-
-        # Tag once the app booted on all hosts
-        on(KAMAL.hosts) do |host|
-          execute *KAMAL.auditor.record("Tagging #{KAMAL.config.absolute_image} as the latest image"), verbosity: :debug
-          execute *KAMAL.app.tag_latest_image
-        end
      end
    end
  end

  desc "start", "Start existing app container on servers"
  def start
-    with_lock do
+    mutating do
      on(KAMAL.hosts) do |host|
        roles = KAMAL.roles_on(host)

        roles.each do |role|
          execute *KAMAL.auditor.record("Started app version #{KAMAL.config.version}"), verbosity: :debug
-          execute *KAMAL.app(role: role, host: host).start, raise_on_non_zero_exit: false
+          execute *KAMAL.app(role: role).start, raise_on_non_zero_exit: false
        end
      end
    end
@@ -47,13 +43,13 @@ class Kamal::Cli::App < Kamal::Cli::Base

  desc "stop", "Stop app container on servers"
  def stop
-    with_lock do
+    mutating do
      on(KAMAL.hosts) do |host|
        roles = KAMAL.roles_on(host)

        roles.each do |role|
          execute *KAMAL.auditor.record("Stopped app", role: role), verbosity: :debug
-          execute *KAMAL.app(role: role, host: host).stop, raise_on_non_zero_exit: false
+          execute *KAMAL.app(role: role).stop, raise_on_non_zero_exit: false
        end
      end
    end
@@ -66,23 +62,21 @@ class Kamal::Cli::App < Kamal::Cli::Base
      roles = KAMAL.roles_on(host)

      roles.each do |role|
-        puts_by_host host, capture_with_info(*KAMAL.app(role: role, host: host).info)
+        puts_by_host host, capture_with_info(*KAMAL.app(role: role).info)
      end
    end
  end

-  desc "exec [CMD]", "Execute a custom command on servers within the app container (use --help to show options)"
+  desc "exec [CMD]", "Execute a custom command on servers (use --help to show options)"
  option :interactive, aliases: "-i", type: :boolean, default: false, desc: "Execute command over ssh for an interactive shell (use for console/bash)"
  option :reuse, type: :boolean, default: false, desc: "Reuse currently running container instead of starting a new one"
-  option :env, aliases: "-e", type: :hash, desc: "Set environment variables for the command"
  def exec(cmd)
-    env = options[:env]
    case
    when options[:interactive] && options[:reuse]
      say "Get current version of running container...", :magenta unless options[:version]
      using_version(options[:version] || current_running_version) do |version|
        say "Launching interactive command with version #{version} via SSH from existing container on #{KAMAL.primary_host}...", :magenta
-        run_locally { exec KAMAL.app(role: KAMAL.primary_role, host: KAMAL.primary_host).execute_in_existing_container_over_ssh(cmd, env: env) }
+        run_locally { exec KAMAL.app(role: KAMAL.primary_role).execute_in_existing_container_over_ssh(cmd, host: KAMAL.primary_host) }
      end

    when options[:interactive]
@@ -90,7 +84,7 @@ class Kamal::Cli::App < Kamal::Cli::Base
      using_version(version_or_latest) do |version|
        say "Launching interactive command with version #{version} via SSH from new container on #{KAMAL.primary_host}...", :magenta
        run_locally do
-          exec KAMAL.app(role: KAMAL.primary_role, host: KAMAL.primary_host).execute_in_new_container_over_ssh(cmd, env: env)
+          exec KAMAL.app(role: KAMAL.primary_role).execute_in_new_container_over_ssh(cmd, host: KAMAL.primary_host)
        end
      end

@@ -104,7 +98,7 @@ class Kamal::Cli::App < Kamal::Cli::Base

          roles.each do |role|
            execute *KAMAL.auditor.record("Executed cmd '#{cmd}' on app version #{version}", role: role), verbosity: :debug
-            puts_by_host host, capture_with_info(*KAMAL.app(role: role, host: host).execute_in_existing_container(cmd, env: env))
+            puts_by_host host, capture_with_info(*KAMAL.app(role: role).execute_in_existing_container(cmd))
          end
        end
      end
@@ -118,7 +112,7 @@ class Kamal::Cli::App < Kamal::Cli::Base

          roles.each do |role|
            execute *KAMAL.auditor.record("Executed cmd '#{cmd}' on app version #{version}"), verbosity: :debug
-            puts_by_host host, capture_with_info(*KAMAL.app(role: role, host: host).execute_in_new_container(cmd, env: env))
+            puts_by_host host, capture_with_info(*KAMAL.app(role: role).execute_in_new_container(cmd))
          end
        end
      end
@@ -133,21 +127,19 @@ class Kamal::Cli::App < Kamal::Cli::Base
  desc "stale_containers", "Detect app stale containers"
  option :stop, aliases: "-s", type: :boolean, default: false, desc: "Stop the stale containers found"
  def stale_containers
-    stop = options[:stop]
+    mutating do
+      stop = options[:stop]
+
+      cli = self

-    with_lock_if_stopping do
      on(KAMAL.hosts) do |host|
        roles = KAMAL.roles_on(host)

        roles.each do |role|
-          app = KAMAL.app(role: role, host: host)
-          versions = capture_with_info(*app.list_versions, raise_on_non_zero_exit: false).split("\n")
-          versions -= [ capture_with_info(*app.current_running_version, raise_on_non_zero_exit: false).strip ]
-
-          versions.each do |version|
+          cli.send(:stale_versions, host: host, role: role).each do |version|
            if stop
              puts_by_host host, "Stopping stale container for role #{role} with version #{version}"
-              execute *app.stop(version: version), raise_on_non_zero_exit: false
+              execute *KAMAL.app(role: role).stop(version: version), raise_on_non_zero_exit: false
            else
              puts_by_host host,  "Detected stale container for role #{role} with version #{version} (use `kamal app stale_containers --stop` to stop)"
            end
@@ -166,15 +158,12 @@ class Kamal::Cli::App < Kamal::Cli::Base
  option :since, aliases: "-s", desc: "Show lines since timestamp (e.g. 2013-01-02T13:23:37Z) or relative (e.g. 42m for 42 minutes)"
  option :lines, type: :numeric, aliases: "-n", desc: "Number of lines to show from each server"
  option :grep, aliases: "-g", desc: "Show lines with grep match only (use this to fetch specific requests by id)"
-  option :grep_options, aliases: "-o", desc: "Additional options supplied to grep"
  option :follow, aliases: "-f", desc: "Follow log on primary server (or specific host set by --hosts)"
  def logs
    # FIXME: Catch when app containers aren't running

    grep = options[:grep]
-    grep_options = options[:grep_options]
    since = options[:since]
-
    if options[:follow]
      lines = options[:lines].presence || ((since || grep) ? nil : 10) # Default to 10 lines if since or grep isn't set

@@ -184,9 +173,8 @@ class Kamal::Cli::App < Kamal::Cli::Base
        KAMAL.specific_roles ||= [ "web" ]
        role = KAMAL.roles_on(KAMAL.primary_host).first

-        app = KAMAL.app(role: role, host: host)
-        info app.follow_logs(host: KAMAL.primary_host, lines: lines, grep: grep, grep_options: grep_options)
-        exec app.follow_logs(host: KAMAL.primary_host, lines: lines, grep: grep, grep_options: grep_options)
+        info KAMAL.app(role: role).follow_logs(host: KAMAL.primary_host, lines: lines, grep: grep)
+        exec KAMAL.app(role: role).follow_logs(host: KAMAL.primary_host, lines: lines, grep: grep)
      end
    else
      lines = options[:lines].presence || ((since || grep) ? nil : 100) # Default to 100 lines if since or grep isn't set
@@ -196,7 +184,7 @@ class Kamal::Cli::App < Kamal::Cli::Base

        roles.each do |role|
          begin
-            puts_by_host host, capture_with_info(*KAMAL.app(role: role, host: host).logs(since: since, lines: lines, grep: grep, grep_options: grep_options))
+            puts_by_host host, capture_with_info(*KAMAL.app(role: role).logs(since: since, lines: lines, grep: grep))
          rescue SSHKit::Command::Failed
            puts_by_host host, "Nothing found"
          end
@@ -207,7 +195,7 @@ class Kamal::Cli::App < Kamal::Cli::Base

  desc "remove", "Remove app containers and images from servers"
  def remove
-    with_lock do
+    mutating do
      stop
      remove_containers
      remove_images
@@ -216,13 +204,13 @@ class Kamal::Cli::App < Kamal::Cli::Base

  desc "remove_container [VERSION]", "Remove app container with given version from servers", hide: true
  def remove_container(version)
-    with_lock do
+    mutating do
      on(KAMAL.hosts) do |host|
        roles = KAMAL.roles_on(host)

        roles.each do |role|
          execute *KAMAL.auditor.record("Removed app container with version #{version}", role: role), verbosity: :debug
-          execute *KAMAL.app(role: role, host: host).remove_container(version: version)
+          execute *KAMAL.app(role: role).remove_container(version: version)
        end
      end
    end
@@ -230,13 +218,13 @@ class Kamal::Cli::App < Kamal::Cli::Base

  desc "remove_containers", "Remove all app containers from servers", hide: true
  def remove_containers
-    with_lock do
+    mutating do
      on(KAMAL.hosts) do |host|
        roles = KAMAL.roles_on(host)

        roles.each do |role|
          execute *KAMAL.auditor.record("Removed all app containers", role: role), verbosity: :debug
-          execute *KAMAL.app(role: role, host: host).remove_containers
+          execute *KAMAL.app(role: role).remove_containers
        end
      end
    end
@@ -244,7 +232,7 @@ class Kamal::Cli::App < Kamal::Cli::Base

  desc "remove_images", "Remove all app images from servers", hide: true
  def remove_images
-    with_lock do
+    mutating do
      on(KAMAL.hosts) do
        execute *KAMAL.auditor.record("Removed all app images"), verbosity: :debug
        execute *KAMAL.app.remove_images
@@ -256,7 +244,7 @@ class Kamal::Cli::App < Kamal::Cli::Base
  def version
    on(KAMAL.hosts) do |host|
      role = KAMAL.roles_on(host).first
-      puts_by_host host, capture_with_info(*KAMAL.app(role: role, host: host).current_running_version).strip
+      puts_by_host host, capture_with_info(*KAMAL.app(role: role).current_running_version).strip
    end
  end

@@ -279,20 +267,23 @@ class Kamal::Cli::App < Kamal::Cli::Base
      version = nil
      on(host) do
        role = KAMAL.roles_on(host).first
-        version = capture_with_info(*KAMAL.app(role: role, host: host).current_running_version).strip
+        version = capture_with_info(*KAMAL.app(role: role).current_running_version).strip
      end
      version.presence
    end

-    def version_or_latest
-      options[:version] || KAMAL.config.latest_tag
+    def stale_versions(host:, role:)
+      versions = nil
+      on(host) do
+        versions = \
+          capture_with_info(*KAMAL.app(role: role).list_versions, raise_on_non_zero_exit: false)
+          .split("\n")
+          .drop(1)
+      end
+      versions
    end

-    def with_lock_if_stopping
-      if options[:stop]
-        with_lock { yield }
-      else
-        yield
-      end
+    def version_or_latest
+      options[:version] || "latest"
    end
 end
--- a/lib/kamal/cli/app/boot.rb
+++ b/lib/kamal/cli/app/boot.rb
@@ -1,30 +1,19 @@
 class Kamal::Cli::App::Boot
-  attr_reader :host, :role, :version, :barrier, :sshkit
-  delegate :execute, :capture_with_info, :capture_with_pretty_json, :info, :error, to: :sshkit
-  delegate :uses_cord?, :assets?, :running_traefik?, to: :role
+  attr_reader :host, :role, :version, :sshkit
+  delegate :execute, :capture_with_info, :info, to: :sshkit
+  delegate :uses_cord?, :assets?, to: :role

-  def initialize(host, role, sshkit, version, barrier)
+  def initialize(host, role, version, sshkit)
    @host = host
    @role = role
    @version = version
-    @barrier = barrier
    @sshkit = sshkit
  end

  def run
    old_version = old_version_renamed_if_clashing

-    wait_at_barrier if queuer?
-
-    begin
-      start_new_version
-    rescue => e
-      close_barrier if gatekeeper?
-      stop_new_version
-      raise
-    end
-
-    release_barrier if gatekeeper?
+    start_new_version

    if old_version
      stop_old_version(old_version)
@@ -32,6 +21,18 @@ class Kamal::Cli::App::Boot
  end

  private
+    def app
+      @app ||= KAMAL.app(role: role)
+    end
+
+    def auditor
+      @auditor = KAMAL.auditor(role: role)
+    end
+
+    def audit(message)
+      execute *auditor.record(message), verbosity: :debug
+    end
+
    def old_version_renamed_if_clashing
      if capture_with_info(*app.container_id_for_version(version), raise_on_non_zero_exit: false).present?
        renamed_version = "#{version}_replaced_#{SecureRandom.hex(8)}"
@@ -45,17 +46,11 @@ class Kamal::Cli::App::Boot

    def start_new_version
      audit "Booted app version #{version}"
-
      execute *app.tie_cord(role.cord_host_file) if uses_cord?
-      hostname = "#{host.to_s[0...51].gsub(/\.+$/, '')}-#{SecureRandom.hex(6)}"
-      execute *app.run(hostname: hostname)
+      execute *app.run(hostname: "#{host}-#{SecureRandom.hex(6)}")
      Kamal::Cli::Healthcheck::Poller.wait_for_healthy(pause_after_ready: true) { capture_with_info(*app.status(version: version)) }
    end

-    def stop_new_version
-      execute *app.stop(version: version), raise_on_non_zero_exit: false
-    end
-
    def stop_old_version(version)
      if uses_cord?
        cord = capture_with_info(*app.cord(version: version), raise_on_non_zero_exit: false).strip
@@ -69,51 +64,4 @@ class Kamal::Cli::App::Boot

      execute *app.clean_up_assets if assets?
    end
-
-    def release_barrier
-      if barrier.open
-        info "First #{KAMAL.primary_role} container is healthy on #{host}, booting any other roles"
-      end
-    end
-
-    def wait_at_barrier
-      info "Waiting for the first healthy #{KAMAL.primary_role} container before booting #{role} on #{host}..."
-      barrier.wait
-      info "First #{KAMAL.primary_role} container is healthy, booting #{role} on #{host}..."
-    rescue Kamal::Cli::Healthcheck::Error
-      info "First #{KAMAL.primary_role} container is unhealthy, not booting #{role} on #{host}"
-      raise
-    end
-
-    def close_barrier
-      if barrier.close
-        info "First #{KAMAL.primary_role} container is unhealthy on #{host}, not booting any other roles"
-        error capture_with_info(*app.logs(version: version))
-        error capture_with_info(*app.container_health_log(version: version))
-      end
-    end
-
-    def barrier_role?
-      role == KAMAL.primary_role
-    end
-
-    def app
-      @app ||= KAMAL.app(role: role, host: host)
-    end
-
-    def auditor
-      @auditor = KAMAL.auditor(role: role)
-    end
-
-    def audit(message)
-      execute *auditor.record(message), verbosity: :debug
-    end
-
-    def gatekeeper?
-      barrier && barrier_role?
-    end
-
-    def queuer?
-      barrier && !barrier_role?
-    end
 end
--- a/lib/kamal/cli/app/prepare_assets.rb
+++ b/lib/kamal/cli/app/prepare_assets.rb
@@ -19,6 +19,6 @@ class Kamal::Cli::App::PrepareAssets

  private
    def app
-      @app ||= KAMAL.app(role: role, host: host)
+      @app ||= KAMAL.app(role: role)
    end
 end
--- a/lib/kamal/cli/base.rb
+++ b/lib/kamal/cli/base.rb
@@ -25,17 +25,12 @@ module Kamal::Cli
    def initialize(*)
      super
      @original_env = ENV.to_h.dup
-      load_env
+      load_envs
      initialize_commander(options_with_subcommand_class_options)
    end

    private
-      def reload_env
-        reset_env
-        load_env
-      end
-
-      def load_env
+      def load_envs
        if destination = options[:destination]
          Dotenv.load(".env.#{destination}", ".env")
        else
@@ -43,27 +38,10 @@ module Kamal::Cli
        end
      end

-      def reset_env
-        replace_env @original_env
-      end
-
-      def replace_env(env)
+      def reload_envs
        ENV.clear
-        ENV.update(env)
-      end
-
-      def with_original_env
-        keeping_current_env do
-          reset_env
-          yield
-        end
-      end
-
-      def keeping_current_env
-        current_env = ENV.to_h.dup
-        yield
-      ensure
-        replace_env(current_env)
+        ENV.update(@original_env)
+        load_envs
      end

      def options_with_subcommand_class_options
@@ -101,27 +79,28 @@ module Kamal::Cli
        puts "  Finished all in #{sprintf("%.1f seconds", runtime)}"
      end

-      def with_lock
-        if KAMAL.holding_lock?
+      def mutating
+        return yield if KAMAL.holding_lock?
+
+        run_hook "pre-connect"
+
+        ensure_run_directory
+
+        acquire_lock
+
+        begin
          yield
-        else
-          ensure_run_and_locks_directory
-
-          acquire_lock
-
-          begin
-            yield
-          rescue
-            begin
-              release_lock
-            rescue => e
-              say "Error releasing the deploy lock: #{e.message}", :red
-            end
-            raise
+        rescue
+          if KAMAL.hold_lock_on_error?
+            error "  \e[31mDeploy lock was not released\e[0m"
+          else
+            release_lock
          end

-          release_lock
+          raise
        end
+
+        release_lock
      end

      def confirming(question)
@@ -162,28 +141,29 @@ module Kamal::Cli
        end
      end

+      def hold_lock_on_error
+        if KAMAL.hold_lock_on_error?
+          yield
+        else
+          KAMAL.hold_lock_on_error = true
+          yield
+          KAMAL.hold_lock_on_error = false
+        end
+      end
+
      def run_hook(hook, **extra_details)
        if !options[:skip_hooks] && KAMAL.hook.hook_exists?(hook)
          details = { hosts: KAMAL.hosts.join(","), command: command, subcommand: subcommand }

          say "Running the #{hook} hook...", :magenta
          run_locally do
-            execute *KAMAL.hook.run(hook, **details, **extra_details)
-          rescue SSHKit::Command::Failed => e
-            raise HookError.new("Hook `#{hook}` failed:\n#{e.message}")
+            KAMAL.with_verbosity(:debug) { execute *KAMAL.hook.run(hook, **details, **extra_details) }
+          rescue SSHKit::Command::Failed
+            raise HookError.new("Hook `#{hook}` failed")
          end
        end
      end

-      def on(*args, &block)
-        if !KAMAL.connected?
-          run_hook "pre-connect"
-          KAMAL.connected = true
-        end
-
-        super
-      end
-
      def command
        @kamal_command ||= begin
          invocation_class, invocation_commands = *first_invocation
@@ -206,18 +186,10 @@ module Kamal::Cli
        instance_variable_get("@_invocations").first
      end

-      def reset_invocation(cli_class)
-        instance_variable_get("@_invocations")[cli_class].pop
-      end
-
-      def ensure_run_and_locks_directory
+      def ensure_run_directory
        on(KAMAL.hosts) do
          execute(*KAMAL.server.ensure_run_directory)
        end
-
-        on(KAMAL.primary_host) do
-          execute(*KAMAL.lock.ensure_locks_directory)
-        end
      end
  end
 end
--- a/lib/kamal/cli/build.rb
+++ b/lib/kamal/cli/build.rb
@@ -5,87 +5,74 @@ class Kamal::Cli::Build < Kamal::Cli::Base

  desc "deliver", "Build app and push app image to registry then pull image on servers"
  def deliver
-    push
-    pull
+    mutating do
+      push
+      pull
+    end
  end

  desc "push", "Build and push app image to registry"
  def push
-    cli = self
+    mutating do
+      cli = self

-    verify_local_dependencies
-    run_hook "pre-build"
+      verify_local_dependencies
+      run_hook "pre-build"

-    uncommitted_changes = Kamal::Git.uncommitted_changes
-
-    if KAMAL.config.builder.git_clone?
-      if uncommitted_changes.present?
-        say "Building from a local git clone, so ignoring these uncommitted changes:\n #{uncommitted_changes}", :yellow
+      if (uncommitted_changes = Kamal::Git.uncommitted_changes).present?
+        say "The following paths have uncommitted changes:\n #{uncommitted_changes}", :yellow
      end

      run_locally do
-        Clone.new(self).prepare
-      end
-    elsif uncommitted_changes.present?
-      say "Building with uncommitted changes:\n #{uncommitted_changes}", :yellow
-    end
+        begin
+          KAMAL.with_verbosity(:debug) do
+            execute *KAMAL.builder.push
+          end
+        rescue SSHKit::Command::Failed => e
+          if e.message =~ /(no builder)|(no such file or directory)/
+            error "Missing compatible builder, so creating a new one first"

-    # Get the command here to ensure the Dir.chdir doesn't interfere with it
-    push = KAMAL.builder.push
-
-    run_locally do
-      begin
-        context_hosts = capture_with_info(*KAMAL.builder.context_hosts).split("\n")
-
-        if context_hosts != KAMAL.builder.config_context_hosts
-          warn "Context hosts have changed, so re-creating builder, was: #{context_hosts.join(", ")}], now: #{KAMAL.builder.config_context_hosts.join(", ")}"
-          cli.remove
-          cli.create
+            if cli.create
+              KAMAL.with_verbosity(:debug) { execute *KAMAL.builder.push }
+            end
+          else
+            raise
+          end
        end
-      rescue SSHKit::Command::Failed => e
-        if e.message =~ /(context not found|no builder|does not exist)/
-          warn "Missing compatible builder, so creating a new one first"
-          cli.create
-        else
-          raise
-        end
-      end
-
-      KAMAL.with_verbosity(:debug) do
-        Dir.chdir(KAMAL.config.builder.build_directory) { execute *push }
      end
    end
  end

  desc "pull", "Pull app image from registry onto servers"
  def pull
-    if (first_hosts = mirror_hosts).any?
-      #  Pull on a single host per mirror first to seed them
-      say "Pulling image on #{first_hosts.join(", ")} to seed the #{"mirror".pluralize(first_hosts.count)}...", :magenta
-      pull_on_hosts(first_hosts)
-      say "Pulling image on remaining hosts...", :magenta
-      pull_on_hosts(KAMAL.hosts - first_hosts)
-    else
-      pull_on_hosts(KAMAL.hosts)
+    mutating do
+      on(KAMAL.hosts) do
+        execute *KAMAL.auditor.record("Pulled image with version #{KAMAL.config.version}"), verbosity: :debug
+        execute *KAMAL.builder.clean, raise_on_non_zero_exit: false
+        execute *KAMAL.builder.pull
+        execute *KAMAL.builder.validate_image
+      end
    end
  end

  desc "create", "Create a build setup"
  def create
-    if (remote_host = KAMAL.config.builder.remote_host)
-      connect_to_remote_host(remote_host)
-    end
+    mutating do
+      if (remote_host = KAMAL.config.builder.remote_host)
+        connect_to_remote_host(remote_host)
+      end

-    run_locally do
-      begin
-        debug "Using builder: #{KAMAL.builder.name}"
-        execute *KAMAL.builder.create
-      rescue SSHKit::Command::Failed => e
-        if e.message =~ /stderr=(.*)/
-          error "Couldn't create remote builder: #{$1}"
-          false
-        else
-          raise
+      run_locally do
+        begin
+          debug "Using builder: #{KAMAL.builder.name}"
+          execute *KAMAL.builder.create
+        rescue SSHKit::Command::Failed => e
+          if e.message =~ /stderr=(.*)/
+            error "Couldn't create remote builder: #{$1}"
+            false
+          else
+            raise
+          end
        end
      end
    end
@@ -93,9 +80,11 @@ class Kamal::Cli::Build < Kamal::Cli::Base

  desc "remove", "Remove build setup"
  def remove
-    run_locally do
-      debug "Using builder: #{KAMAL.builder.name}"
-      execute *KAMAL.builder.remove
+    mutating do
+      run_locally do
+        debug "Using builder: #{KAMAL.builder.name}"
+        execute *KAMAL.builder.remove
+      end
    end
  end

@@ -125,37 +114,10 @@ class Kamal::Cli::Build < Kamal::Cli::Base
    def connect_to_remote_host(remote_host)
      remote_uri = URI.parse(remote_host)
      if remote_uri.scheme == "ssh"
-        host = SSHKit::Host.new(
-          hostname: remote_uri.host,
-          ssh_options: { user: remote_uri.user, port: remote_uri.port }.compact
-        )
-        on(host, options) do
+        options = { user: remote_uri.user, port: remote_uri.port }.compact
+        on(remote_uri.host, options) do
          execute "true"
        end
      end
    end
-
-    def mirror_hosts
-      if KAMAL.hosts.many?
-        mirror_hosts = Concurrent::Hash.new
-        on(KAMAL.hosts) do |host|
-          first_mirror = capture_with_info(*KAMAL.builder.first_mirror).strip.presence
-          mirror_hosts[first_mirror] ||= host.to_s if first_mirror
-        rescue SSHKit::Command::Failed => e
-          raise unless e.message =~ /error calling index: reflect: slice index out of range/
-        end
-        mirror_hosts.values
-      else
-        []
-      end
-    end
-
-    def pull_on_hosts(hosts)
-      on(hosts) do
-        execute *KAMAL.auditor.record("Pulled image with version #{KAMAL.config.version}"), verbosity: :debug
-        execute *KAMAL.builder.clean, raise_on_non_zero_exit: false
-        execute *KAMAL.builder.pull
-        execute *KAMAL.builder.validate_image
-      end
-    end
 end
--- a/lib/kamal/cli/build/clone.rb
+++ b/lib/kamal/cli/build/clone.rb
@@ -1,61 +0,0 @@
-require "uri"
-
-class Kamal::Cli::Build::Clone
-  attr_reader :sshkit
-  delegate :info, :error, :execute, :capture_with_info, to: :sshkit
-
-  def initialize(sshkit)
-    @sshkit = sshkit
-  end
-
-  def prepare
-    begin
-      clone_repo
-    rescue SSHKit::Command::Failed => e
-      if e.message =~ /already exists and is not an empty directory/
-        reset
-      else
-        raise Kamal::Cli::Build::BuildError, "Failed to clone repo: #{e.message}"
-      end
-    end
-
-    validate!
-  rescue Kamal::Cli::Build::BuildError => e
-    error "Error preparing clone: #{e.message}, deleting and retrying..."
-
-    FileUtils.rm_rf KAMAL.config.builder.clone_directory
-    clone_repo
-    validate!
-  end
-
-  private
-    def clone_repo
-      info "Cloning repo into build directory `#{KAMAL.config.builder.build_directory}`..."
-
-      FileUtils.mkdir_p KAMAL.config.builder.clone_directory
-      execute *KAMAL.builder.clone
-    end
-
-    def reset
-      info "Resetting local clone as `#{KAMAL.config.builder.build_directory}` already exists..."
-
-      KAMAL.builder.clone_reset_steps.each { |step| execute *step }
-    rescue SSHKit::Command::Failed => e
-      raise Kamal::Cli::Build::BuildError, "Failed to clone repo: #{e.message}"
-    end
-
-    def validate!
-      status = capture_with_info(*KAMAL.builder.clone_status).strip
-
-      unless status.empty?
-        raise Kamal::Cli::Build::BuildError, "Clone in #{KAMAL.config.builder.build_directory} is dirty, #{status}"
-      end
-
-      revision = capture_with_info(*KAMAL.builder.clone_revision).strip
-      if revision != Kamal::Git.revision
-        raise Kamal::Cli::Build::BuildError, "Clone in #{KAMAL.config.builder.build_directory} is not on the correct revision, expected `#{Kamal::Git.revision}` but got `#{revision}`"
-      end
-    rescue SSHKit::Command::Failed => e
-      raise Kamal::Cli::Build::BuildError, "Failed to validate clone: #{e.message}"
-    end
-end
--- a/lib/kamal/cli/env.rb
+++ b/lib/kamal/cli/env.rb
@@ -3,13 +3,13 @@ require "tempfile"
 class Kamal::Cli::Env < Kamal::Cli::Base
  desc "push", "Push the env file to the remote hosts"
  def push
-    with_lock do
+    mutating do
      on(KAMAL.hosts) do
        execute *KAMAL.auditor.record("Pushed env files"), verbosity: :debug

        KAMAL.roles_on(host).each do |role|
-          execute *KAMAL.app(role: role, host: host).make_env_directory
-          upload! role.env(host).secrets_io, role.env(host).secrets_file, mode: 400
+          execute *KAMAL.app(role: role).make_env_directory
+          upload! role.env.secrets_io, role.env.secrets_file, mode: 400
        end
      end

@@ -30,12 +30,12 @@ class Kamal::Cli::Env < Kamal::Cli::Base

  desc "delete", "Delete the env file from the remote hosts"
  def delete
-    with_lock do
+    mutating do
      on(KAMAL.hosts) do
        execute *KAMAL.auditor.record("Deleted env files"), verbosity: :debug

        KAMAL.roles_on(host).each do |role|
-          execute *KAMAL.app(role: role, host: host).remove_env_file
+          execute *KAMAL.app(role: role).remove_env_file
        end
      end

--- a/lib/kamal/cli/healthcheck.rb
+++ b/lib/kamal/cli/healthcheck.rb
@@ -0,0 +1,21 @@
+class Kamal::Cli::Healthcheck < Kamal::Cli::Base
+  default_command :perform
+
+  desc "perform", "Health check current app version"
+  def perform
+    raise "The primary host is not configured to run Traefik" unless KAMAL.config.role(KAMAL.config.primary_role).running_traefik?
+    on(KAMAL.primary_host) do
+      begin
+        execute *KAMAL.healthcheck.run
+        Poller.wait_for_healthy { capture_with_info(*KAMAL.healthcheck.status) }
+      rescue Poller::HealthcheckError => e
+        error capture_with_info(*KAMAL.healthcheck.logs)
+        error capture_with_pretty_json(*KAMAL.healthcheck.container_health_log)
+        raise
+      ensure
+        execute *KAMAL.healthcheck.stop, raise_on_non_zero_exit: false
+        execute *KAMAL.healthcheck.remove, raise_on_non_zero_exit: false
+      end
+    end
+  end
+end
--- a/lib/kamal/cli/healthcheck/barrier.rb
+++ b/lib/kamal/cli/healthcheck/barrier.rb
@@ -1,31 +0,0 @@
-class Kamal::Cli::Healthcheck::Barrier
-  def initialize
-    @ivar = Concurrent::IVar.new
-  end
-
-  def close
-    set(false)
-  end
-
-  def open
-    set(true)
-  end
-
-  def wait
-    unless opened?
-      raise Kamal::Cli::Healthcheck::Error.new("Halted at barrier")
-    end
-  end
-
-  private
-    def opened?
-      @ivar.value
-    end
-
-    def set(value)
-      @ivar.set(value)
-      true
-    rescue Concurrent::MultipleAssignmentError
-      false
-    end
-end
--- a/lib/kamal/cli/healthcheck/error.rb
+++ b/lib/kamal/cli/healthcheck/error.rb
@@ -1,2 +0,0 @@
-class Kamal::Cli::Healthcheck::Error < StandardError
-end
--- a/lib/kamal/cli/healthcheck/poller.rb
+++ b/lib/kamal/cli/healthcheck/poller.rb
@@ -3,10 +3,11 @@ module Kamal::Cli::Healthcheck::Poller

  TRAEFIK_UPDATE_DELAY = 5

+  class HealthcheckError < StandardError; end

  def wait_for_healthy(pause_after_ready: false, &block)
    attempt = 1
-    max_attempts = KAMAL.config.healthcheck.max_attempts
+    max_attempts = KAMAL.config.healthcheck["max_attempts"]

    begin
      case status = block.call
@@ -15,9 +16,9 @@ module Kamal::Cli::Healthcheck::Poller
      when "running" # No health check configured
        sleep KAMAL.config.readiness_delay if pause_after_ready
      else
-        raise Kamal::Cli::Healthcheck::Error, "container not ready (#{status})"
+        raise HealthcheckError, "container not ready (#{status})"
      end
-    rescue Kamal::Cli::Healthcheck::Error => e
+    rescue HealthcheckError => e
      if attempt <= max_attempts
        info "#{e.message}, retrying in #{attempt}s (attempt #{attempt}/#{max_attempts})..."
        sleep attempt
@@ -33,16 +34,16 @@ module Kamal::Cli::Healthcheck::Poller

  def wait_for_unhealthy(pause_after_ready: false, &block)
    attempt = 1
-    max_attempts = KAMAL.config.healthcheck.max_attempts
+    max_attempts = KAMAL.config.healthcheck["max_attempts"]

    begin
      case status = block.call
      when "unhealthy"
        sleep TRAEFIK_UPDATE_DELAY if pause_after_ready
      else
-        raise Kamal::Cli::Healthcheck::Error, "container not unhealthy (#{status})"
+        raise HealthcheckError, "container not unhealthy (#{status})"
      end
-    rescue Kamal::Cli::Healthcheck::Error => e
+    rescue HealthcheckError => e
      if attempt <= max_attempts
        info "#{e.message}, retrying in #{attempt}s (attempt #{attempt}/#{max_attempts})..."
        sleep attempt
--- a/lib/kamal/cli/main.rb
+++ b/lib/kamal/cli/main.rb
@@ -3,14 +3,13 @@ class Kamal::Cli::Main < Kamal::Cli::Base
  option :skip_push, aliases: "-P", type: :boolean, default: false, desc: "Skip image build and push"
  def setup
    print_runtime do
-      with_lock do
+      mutating do
        invoke_options = deploy_options

        say "Ensure Docker is installed...", :magenta
        invoke "kamal:cli:server:bootstrap", [], invoke_options

-        say "Evaluate and push env files...", :magenta
-        invoke "kamal:cli:main:envify", [], invoke_options
+        say "Push env files...", :magenta
        invoke "kamal:cli:env:push", [], invoke_options

        invoke "kamal:cli:accessory:boot", [ "all" ], invoke_options
@@ -23,25 +22,30 @@ class Kamal::Cli::Main < Kamal::Cli::Base
  option :skip_push, aliases: "-P", type: :boolean, default: false, desc: "Skip image build and push"
  def deploy
    runtime = print_runtime do
-      invoke_options = deploy_options
+      mutating do
+        invoke_options = deploy_options

-      say "Log into image registry...", :magenta
-      invoke "kamal:cli:registry:login", [], invoke_options.merge(skip_local: options[:skip_push])
+        say "Log into image registry...", :magenta
+        invoke "kamal:cli:registry:login", [], invoke_options

-      if options[:skip_push]
-        say "Pull app image...", :magenta
-        invoke "kamal:cli:build:pull", [], invoke_options
-      else
-        say "Build and push app image...", :magenta
-        invoke "kamal:cli:build:deliver", [], invoke_options
-      end
+        if options[:skip_push]
+          say "Pull app image...", :magenta
+          invoke "kamal:cli:build:pull", [], invoke_options
+        else
+          say "Build and push app image...", :magenta
+          invoke "kamal:cli:build:deliver", [], invoke_options
+        end

-      with_lock do
        run_hook "pre-deploy"

        say "Ensure Traefik is running...", :magenta
        invoke "kamal:cli:traefik:boot", [], invoke_options

+        if KAMAL.config.role(KAMAL.config.primary_role).running_traefik?
+          say "Ensure app can pass healthcheck...", :magenta
+          invoke "kamal:cli:healthcheck:perform", [], invoke_options
+        end
+
        say "Detect stale containers...", :magenta
        invoke "kamal:cli:app:stale_containers", [], invoke_options.merge(stop: true)

@@ -59,19 +63,22 @@ class Kamal::Cli::Main < Kamal::Cli::Base
  option :skip_push, aliases: "-P", type: :boolean, default: false, desc: "Skip image build and push"
  def redeploy
    runtime = print_runtime do
-      invoke_options = deploy_options
+      mutating do
+        invoke_options = deploy_options

-      if options[:skip_push]
-        say "Pull app image...", :magenta
-        invoke "kamal:cli:build:pull", [], invoke_options
-      else
-        say "Build and push app image...", :magenta
-        invoke "kamal:cli:build:deliver", [], invoke_options
-      end
+        if options[:skip_push]
+          say "Pull app image...", :magenta
+          invoke "kamal:cli:build:pull", [], invoke_options
+        else
+          say "Build and push app image...", :magenta
+          invoke "kamal:cli:build:deliver", [], invoke_options
+        end

-      with_lock do
        run_hook "pre-deploy"

+        say "Ensure app can pass healthcheck...", :magenta
+        invoke "kamal:cli:healthcheck:perform", [], invoke_options
+
        say "Detect stale containers...", :magenta
        invoke "kamal:cli:app:stale_containers", [], invoke_options.merge(stop: true)

@@ -86,7 +93,7 @@ class Kamal::Cli::Main < Kamal::Cli::Base
  def rollback(version)
    rolled_back = false
    runtime = print_runtime do
-      with_lock do
+      mutating do
        invoke_options = deploy_options

        KAMAL.config.version = version
@@ -127,18 +134,6 @@ class Kamal::Cli::Main < Kamal::Cli::Base
    end
  end

-  desc "docs", "Show Kamal documentation for configuration setting"
-  def docs(section = nil)
-    case section
-    when NilClass
-      puts Kamal::Configuration.validation_doc
-    else
-      puts Kamal::Configuration.const_get(section.titlecase.to_sym).validation_doc
-    end
-  rescue NameError
-    puts "No documentation found for #{section}"
-  end
-
  desc "init", "Create config stub in config/deploy.yml and env stub in .env"
  option :bundle, type: :boolean, default: false, desc: "Add Kamal to the Gemfile and create a bin/kamal binstub"
  def init
@@ -190,60 +185,23 @@ class Kamal::Cli::Main < Kamal::Cli::Base
      env_path          = ".env"
    end

-    if Pathname.new(File.expand_path(env_template_path)).exist?
-      # Ensure existing env doesn't pollute template evaluation
-      content = with_original_env { ERB.new(File.read(env_template_path), trim_mode: "-").result }
-      File.write(env_path, content, perm: 0600)
+    File.write(env_path, ERB.new(File.read(env_template_path), trim_mode: "-").result, perm: 0600)

-      unless options[:skip_push]
-        reload_env
-        invoke "kamal:cli:env:push", options
-      end
-    else
-      puts "Skipping envify (no #{env_template_path} exist)"
+    unless options[:skip_push]
+      reload_envs
+      invoke "kamal:cli:env:push", options
    end
  end

  desc "remove", "Remove Traefik, app, accessories, and registry session from servers"
  option :confirmed, aliases: "-y", type: :boolean, default: false, desc: "Proceed without confirmation question"
  def remove
-    confirming "This will remove all containers and images. Are you sure?" do
-      with_lock do
+    mutating do
+      confirming "This will remove all containers and images. Are you sure?" do
        invoke "kamal:cli:traefik:remove", [], options.without(:confirmed)
        invoke "kamal:cli:app:remove", [], options.without(:confirmed)
        invoke "kamal:cli:accessory:remove", [ "all" ], options
-        invoke "kamal:cli:registry:logout", [], options.without(:confirmed).merge(skip_local: true)
-      end
-    end
-  end
-
-  desc "downgrade", "Downgrade from Kamal 2 to 1.9"
-  option :confirmed, aliases: "-y", type: :boolean, default: false, desc: "Proceed without confirmation question"
-  option :rolling, type: :boolean, default: false, desc: "Downgrade one host at a time"
-  def downgrade
-    confirming "This will replace Traefik with kamal-proxy and restart all accessories" do
-      with_lock do
-        if options[:rolling]
-          (KAMAL.hosts | KAMAL.accessory_hosts).each do |host|
-            KAMAL.with_specific_hosts(host) do
-              say "Downgrading #{host}...", :magenta
-              if KAMAL.hosts.include?(host)
-                invoke "kamal:cli:traefik:downgrade", [], options.merge(confirmed: true, rolling: false)
-                reset_invocation(Kamal::Cli::Traefik)
-              end
-              if KAMAL.accessory_hosts.include?(host)
-                invoke "kamal:cli:accessory:downgrade", [ "all" ], options.merge(confirmed: true, rolling: false)
-                reset_invocation(Kamal::Cli::Accessory)
-              end
-              say "Downgraded #{host}", :magenta
-            end
-          end
-        else
-          say "Downgrading all hosts...", :magenta
-          invoke "kamal:cli:traefik:downgrade", [], options.merge(confirmed: true)
-          invoke "kamal:cli:accessory:downgrade", [ "all" ], options.merge(confirmed: true)
-          say "Downgraded all hosts", :magenta
-        end
+        invoke "kamal:cli:registry:logout", [], options.without(:confirmed)
      end
    end
  end
@@ -265,6 +223,9 @@ class Kamal::Cli::Main < Kamal::Cli::Base
  desc "env", "Manage environment files"
  subcommand "env", Kamal::Cli::Env

+  desc "healthcheck", "Healthcheck application"
+  subcommand "healthcheck", Kamal::Cli::Healthcheck
+
  desc "lock", "Manage the deploy lock"
  subcommand "lock", Kamal::Cli::Lock

@@ -285,11 +246,11 @@ class Kamal::Cli::Main < Kamal::Cli::Base
      begin
        on(KAMAL.hosts) do
          KAMAL.roles_on(host).each do |role|
-            container_id = capture_with_info(*KAMAL.app(role: role, host: host).container_id_for_version(version))
+            container_id = capture_with_info(*KAMAL.app(role: role).container_id_for_version(version))
            raise "Container not found" unless container_id.present?
          end
        end
-      rescue SSHKit::Runner::ExecuteError, SSHKit::Runner::MultipleExecuteError => e
+      rescue SSHKit::Runner::ExecuteError => e
        if e.message =~ /Container not found/
          say "Error looking for container version #{version}: #{e.message}"
          return false
--- a/lib/kamal/cli/prune.rb
+++ b/lib/kamal/cli/prune.rb
@@ -1,7 +1,7 @@
 class Kamal::Cli::Prune < Kamal::Cli::Base
  desc "all", "Prune unused images and stopped containers"
  def all
-    with_lock do
+    mutating do
      containers
      images
    end
@@ -9,7 +9,7 @@ class Kamal::Cli::Prune < Kamal::Cli::Base

  desc "images", "Prune unused images"
  def images
-    with_lock do
+    mutating do
      on(KAMAL.hosts) do
        execute *KAMAL.auditor.record("Pruned images"), verbosity: :debug
        execute *KAMAL.prune.dangling_images
@@ -24,7 +24,7 @@ class Kamal::Cli::Prune < Kamal::Cli::Base
    retain = options.fetch(:retain, KAMAL.config.retain_containers)
    raise "retain must be at least 1" if retain < 1

-    with_lock do
+    mutating do
      on(KAMAL.hosts) do
        execute *KAMAL.auditor.record("Pruned containers"), verbosity: :debug
        execute *KAMAL.prune.app_containers(retain: retain)
--- a/lib/kamal/cli/registry.rb
+++ b/lib/kamal/cli/registry.rb
@@ -1,17 +1,18 @@
 class Kamal::Cli::Registry < Kamal::Cli::Base
  desc "login", "Log in to registry locally and remotely"
-  option :skip_local, aliases: "-L", type: :boolean, default: false, desc: "Skip local login"
-  option :skip_remote, aliases: "-R", type: :boolean, default: false, desc: "Skip remote login"
  def login
-    run_locally    { execute *KAMAL.registry.login } unless options[:skip_local]
-    on(KAMAL.hosts) { execute *KAMAL.registry.login } unless options[:skip_remote]
+    run_locally    { execute *KAMAL.registry.login }
+    on(KAMAL.hosts) { execute *KAMAL.registry.login }
+  # FIXME: This rescue needed?
+  rescue ArgumentError => e
+    puts e.message
  end

-  desc "logout", "Log out of registry locally and remotely"
-  option :skip_local, aliases: "-L", type: :boolean, default: false, desc: "Skip local login"
-  option :skip_remote, aliases: "-R", type: :boolean, default: false, desc: "Skip remote login"
+  desc "logout", "Log out of registry remotely"
  def logout
-    run_locally    { execute *KAMAL.registry.logout } unless options[:skip_local]
-    on(KAMAL.hosts) { execute *KAMAL.registry.logout } unless options[:skip_remote]
+    on(KAMAL.hosts) { execute *KAMAL.registry.logout }
+  # FIXME: This rescue needed?
+  rescue ArgumentError => e
+    puts e.message
  end
 end
--- a/lib/kamal/cli/server.rb
+++ b/lib/kamal/cli/server.rb
@@ -1,49 +1,25 @@
 class Kamal::Cli::Server < Kamal::Cli::Base
-  desc "exec", "Run a custom command on the server (use --help to show options)"
-  option :interactive, type: :boolean, aliases: "-i", default: false, desc: "Run the command interactively (use for console/bash)"
-  def exec(cmd)
-    hosts = KAMAL.hosts | KAMAL.accessory_hosts
-
-    case
-    when options[:interactive]
-      host = KAMAL.primary_host
-
-      say "Running '#{cmd}' on #{host} interactively...", :magenta
-
-      run_locally { exec KAMAL.server.run_over_ssh(cmd, host: host) }
-    else
-      say "Running '#{cmd}' on #{hosts.join(', ')}...", :magenta
-
-      on(hosts) do |host|
-        execute *KAMAL.auditor.record("Executed cmd '#{cmd}' on #{host}"), verbosity: :debug
-        puts_by_host host, capture_with_info(cmd)
-      end
-    end
-  end
-
  desc "bootstrap", "Set up Docker to run Kamal apps"
  def bootstrap
-    with_lock do
-      missing = []
+    missing = []

-      on(KAMAL.hosts | KAMAL.accessory_hosts) do |host|
-        unless execute(*KAMAL.docker.installed?, raise_on_non_zero_exit: false)
-          if execute(*KAMAL.docker.superuser?, raise_on_non_zero_exit: false)
-            info "Missing Docker on #{host}. Installing…"
-            execute *KAMAL.docker.install
-          else
-            missing << host
-          end
+    on(KAMAL.hosts | KAMAL.accessory_hosts) do |host|
+      unless execute(*KAMAL.docker.installed?, raise_on_non_zero_exit: false)
+        if execute(*KAMAL.docker.superuser?, raise_on_non_zero_exit: false)
+          info "Missing Docker on #{host}. Installing…"
+          execute *KAMAL.docker.install
+        else
+          missing << host
        end
-
-        execute(*KAMAL.server.ensure_run_directory)
      end

-      if missing.any?
-        raise "Docker is not installed on #{missing.join(", ")} and can't be automatically installed without having root access and either `wget` or `curl`. Install Docker manually: https://docs.docker.com/engine/install/"
-      end
-
-      run_hook "docker-setup"
+      execute(*KAMAL.server.ensure_run_directory)
    end
+
+    if missing.any?
+      raise "Docker is not installed on #{missing.join(", ")} and can't be automatically installed without having root access and either `wget` or `curl`. Install Docker manually: https://docs.docker.com/engine/install/"
+    end
+
+    run_hook "docker-setup"
  end
 end
--- a/lib/kamal/cli/templates/deploy.yml
+++ b/lib/kamal/cli/templates/deploy.yml
@@ -63,7 +63,7 @@ registry:
 #     directories:
 #       - data:/data

-# Configure custom arguments for Traefik. Be sure to reboot traefik when you modify it.
+# Configure custom arguments for Traefik
 # traefik:
 #   args:
 #     accesslog: true
--- a/lib/kamal/cli/templates/sample_hooks/docker-setup.sample
+++ b/lib/kamal/cli/templates/sample_hooks/docker-setup.sample
@@ -2,12 +2,6 @@

 # A sample docker-setup hook
 #
-# Sets up a Docker network on defined hosts which can then be used by the application’s containers
+# Sets up a Docker network which can then be used by the application’s containers

-hosts = ENV["KAMAL_HOSTS"].split(",")
-
-hosts.each do |ip|
-  destination = "root@#{ip}"
-  puts "Creating a Docker network \"kamal\" on #{destination}"
-  `ssh #{destination} docker network create kamal`
-end
+ssh user@example.com docker network create kamal
--- a/lib/kamal/cli/traefik.rb
+++ b/lib/kamal/cli/traefik.rb
@@ -1,7 +1,7 @@
 class Kamal::Cli::Traefik < Kamal::Cli::Base
  desc "boot", "Boot Traefik on servers"
  def boot
-    with_lock do
+    mutating do
      on(KAMAL.traefik_hosts) do
        execute *KAMAL.registry.login
        execute *KAMAL.traefik.start_or_run
@@ -14,7 +14,7 @@ class Kamal::Cli::Traefik < Kamal::Cli::Base
  option :confirmed, aliases: "-y", type: :boolean, default: false, desc: "Proceed without confirmation question"
  def reboot
    confirming "This will cause a brief outage on each host. Are you sure?" do
-      with_lock do
+      mutating do
        host_groups = options[:rolling] ? KAMAL.traefik_hosts : [ KAMAL.traefik_hosts ]
        host_groups.each do |hosts|
          host_list = Array(hosts).join(",")
@@ -34,7 +34,7 @@ class Kamal::Cli::Traefik < Kamal::Cli::Base

  desc "start", "Start existing Traefik container on servers"
  def start
-    with_lock do
+    mutating do
      on(KAMAL.traefik_hosts) do
        execute *KAMAL.auditor.record("Started traefik"), verbosity: :debug
        execute *KAMAL.traefik.start
@@ -44,7 +44,7 @@ class Kamal::Cli::Traefik < Kamal::Cli::Base

  desc "stop", "Stop existing Traefik container on servers"
  def stop
-    with_lock do
+    mutating do
      on(KAMAL.traefik_hosts) do
        execute *KAMAL.auditor.record("Stopped traefik"), verbosity: :debug
        execute *KAMAL.traefik.stop, raise_on_non_zero_exit: false
@@ -54,7 +54,7 @@ class Kamal::Cli::Traefik < Kamal::Cli::Base

  desc "restart", "Restart existing Traefik container on servers"
  def restart
-    with_lock do
+    mutating do
      stop
      start
    end
@@ -69,31 +69,29 @@ class Kamal::Cli::Traefik < Kamal::Cli::Base
  option :since, aliases: "-s", desc: "Show logs since timestamp (e.g. 2013-01-02T13:23:37Z) or relative (e.g. 42m for 42 minutes)"
  option :lines, type: :numeric, aliases: "-n", desc: "Number of log lines to pull from each server"
  option :grep, aliases: "-g", desc: "Show lines with grep match only (use this to fetch specific requests by id)"
-  option :grep_options, aliases: "-o", desc: "Additional options supplied to grep"
  option :follow, aliases: "-f", desc: "Follow logs on primary server (or specific host set by --hosts)"
  def logs
    grep = options[:grep]
-    grep_options = options[:grep_options]

    if options[:follow]
      run_locally do
        info "Following logs on #{KAMAL.primary_host}..."
-        info KAMAL.traefik.follow_logs(host: KAMAL.primary_host, grep: grep, grep_options: grep_options)
-        exec KAMAL.traefik.follow_logs(host: KAMAL.primary_host, grep: grep, grep_options: grep_options)
+        info KAMAL.traefik.follow_logs(host: KAMAL.primary_host, grep: grep)
+        exec KAMAL.traefik.follow_logs(host: KAMAL.primary_host, grep: grep)
      end
    else
      since = options[:since]
      lines = options[:lines].presence || ((since || grep) ? nil : 100) # Default to 100 lines if since or grep isn't set

      on(KAMAL.traefik_hosts) do |host|
-        puts_by_host host, capture(*KAMAL.traefik.logs(since: since, lines: lines, grep: grep, grep_options: grep_options)), type: "Traefik"
+        puts_by_host host, capture(*KAMAL.traefik.logs(since: since, lines: lines, grep: grep)), type: "Traefik"
      end
    end
  end

  desc "remove", "Remove Traefik container and image from servers"
  def remove
-    with_lock do
+    mutating do
      stop
      remove_container
      remove_image
@@ -102,7 +100,7 @@ class Kamal::Cli::Traefik < Kamal::Cli::Base

  desc "remove_container", "Remove Traefik container from servers", hide: true
  def remove_container
-    with_lock do
+    mutating do
      on(KAMAL.traefik_hosts) do
        execute *KAMAL.auditor.record("Removed traefik container"), verbosity: :debug
        execute *KAMAL.traefik.remove_container
@@ -112,51 +110,11 @@ class Kamal::Cli::Traefik < Kamal::Cli::Base

  desc "remove_image", "Remove Traefik image from servers", hide: true
  def remove_image
-    with_lock do
+    mutating do
      on(KAMAL.traefik_hosts) do
        execute *KAMAL.auditor.record("Removed traefik image"), verbosity: :debug
        execute *KAMAL.traefik.remove_image
      end
    end
  end
-
-  desc "downgrade", "Downgrade to Traefik on servers (stop container, remove container, start new container, reboot app)"
-  option :rolling, type: :boolean, default: false, desc: "Reboot proxy on hosts in sequence, rather than in parallel"
-  option :confirmed, aliases: "-y", type: :boolean, default: false, desc: "Proceed without confirmation question"
-  def downgrade
-    invoke_options = { "version" => KAMAL.config.latest_tag }.merge(options)
-
-    confirming "This will cause a brief outage on each host. Are you sure?" do
-      host_groups = options[:rolling] ? KAMAL.hosts : [ KAMAL.hosts ]
-      host_groups.each do |hosts|
-        host_list = Array(hosts).join(",")
-        say "Downgrading to Traefik on #{host_list}...", :magenta
-        run_hook "pre-traefik-reboot", hosts: host_list
-        on(hosts) do |host|
-          execute *KAMAL.auditor.record("Rebooted Traefik"), verbosity: :debug
-          execute *KAMAL.registry.login
-
-          "Stopping and removing kamal-proxy on #{host}, if running..."
-          execute *KAMAL.traefik.cleanup_kamal_proxy
-
-          "Stopping and removing Traefik on #{host}, if running..."
-          execute *KAMAL.traefik.stop, raise_on_non_zero_exit: false
-          execute *KAMAL.traefik.remove_container
-          execute *KAMAL.traefik.remove_image
-        end
-
-        KAMAL.with_specific_hosts(hosts) do
-          invoke "kamal:cli:traefik:boot", [], invoke_options
-          reset_invocation(Kamal::Cli::Traefik)
-          invoke "kamal:cli:app:boot", [], invoke_options
-          reset_invocation(Kamal::Cli::App)
-          invoke "kamal:cli:prune:all", [], invoke_options
-          reset_invocation(Kamal::Cli::Prune)
-        end
-
-        run_hook "post-traefik-reboot", hosts: host_list
-        say "Downgraded to Traefik on #{host_list}", :magenta
-      end
-    end
-  end
 end
--- a/lib/kamal/commander.rb
+++ b/lib/kamal/commander.rb
@@ -2,14 +2,12 @@ require "active_support/core_ext/enumerable"
 require "active_support/core_ext/module/delegation"

 class Kamal::Commander
-  attr_accessor :verbosity, :holding_lock, :connected
-  delegate :hosts, :roles, :primary_host, :primary_role, :roles_on, :traefik_hosts, :accessory_hosts, to: :specifics
+  attr_accessor :verbosity, :holding_lock, :hold_lock_on_error

  def initialize
    self.verbosity = :info
    self.holding_lock = false
-    self.connected = false
-    @specifics = nil
+    self.hold_lock_on_error = false
  end

  def config
@@ -26,12 +24,10 @@ class Kamal::Commander
  attr_reader :specific_roles, :specific_hosts

  def specific_primary!
-    @specifics = nil
    self.specific_hosts = [ config.primary_host ]
  end

  def specific_roles=(role_names)
-    @specifics = nil
    if role_names.present?
      @specific_roles = Kamal::Utils.filter_specific_items(role_names, config.roles)

@@ -44,7 +40,6 @@ class Kamal::Commander
  end

  def specific_hosts=(hosts)
-    @specifics = nil
    if hosts.present?
      @specific_hosts = Kamal::Utils.filter_specific_items(hosts, config.all_hosts)

@@ -56,11 +51,37 @@ class Kamal::Commander
    end
  end

-  def with_specific_hosts(hosts)
-    original_hosts, self.specific_hosts = specific_hosts, hosts
-    yield
-  ensure
-    self.specific_hosts = original_hosts
+  def primary_host
+    # Given a list of specific roles, make an effort to match up with the primary_role
+    specific_hosts&.first || specific_roles&.detect { |role| role == config.primary_role }&.primary_host || specific_roles&.first&.primary_host || config.primary_host
+  end
+
+  def primary_role
+    roles_on(primary_host).first
+  end
+
+  def roles
+    (specific_roles || config.roles).select do |role|
+      ((specific_hosts || config.all_hosts) & role.hosts).any?
+    end
+  end
+
+  def hosts
+    (specific_hosts || config.all_hosts).select do |host|
+      (specific_roles || config.roles).flat_map(&:hosts).include?(host)
+    end
+  end
+
+  def roles_on(host)
+    roles.select { |role| role.hosts.include?(host.to_s) }
+  end
+
+  def traefik_hosts
+    specific_hosts || config.traefik_hosts
+  end
+
+  def accessory_hosts
+    specific_hosts || config.accessories.flat_map(&:hosts)
  end

  def accessory_names
@@ -72,8 +93,8 @@ class Kamal::Commander
  end


-  def app(role: nil, host: nil)
-    Kamal::Commands::App.new(config, role: role, host: host)
+  def app(role: nil)
+    Kamal::Commands::App.new(config, role: role)
  end

  def accessory(name)
@@ -145,8 +166,8 @@ class Kamal::Commander
    self.holding_lock
  end

-  def connected?
-    self.connected
+  def hold_lock_on_error?
+    self.hold_lock_on_error
  end

  private
@@ -160,8 +181,4 @@ class Kamal::Commander
      SSHKit.config.command_map[:docker] = "docker" # No need to use /usr/bin/env, just clogs up the logs
      SSHKit.config.output_verbosity = verbosity
    end
-
-    def specifics
-      @specifics ||= Kamal::Commander::Specifics.new(config, specific_hosts, specific_roles)
-    end
 end
--- a/lib/kamal/commander/specifics.rb
+++ b/lib/kamal/commander/specifics.rb
@@ -1,49 +0,0 @@
-class Kamal::Commander::Specifics
-  attr_reader :primary_host, :primary_role, :hosts, :roles
-  delegate :stable_sort!, to: Kamal::Utils
-
-  def initialize(config, specific_hosts, specific_roles)
-    @config, @specific_hosts, @specific_roles = config, specific_hosts, specific_roles
-
-    @roles, @hosts = specified_roles, specified_hosts
-
-    @primary_host = specific_hosts&.first || primary_specific_role&.primary_host || config.primary_host
-    @primary_role = primary_or_first_role(roles_on(primary_host))
-
-    stable_sort!(roles) { |role| role == primary_role ? 0 : 1 }
-    stable_sort!(hosts) { |host| roles_on(host).any? { |role| role == primary_role } ? 0 : 1 }
-  end
-
-  def roles_on(host)
-    roles.select { |role| role.hosts.include?(host.to_s) }
-  end
-
-  def traefik_hosts
-    config.traefik_hosts & specified_hosts
-  end
-
-  def accessory_hosts
-    config.accessories.flat_map(&:hosts) & specified_hosts
-  end
-
-  private
-    attr_reader :config, :specific_hosts, :specific_roles
-
-    def primary_specific_role
-      primary_or_first_role(specific_roles) if specific_roles.present?
-    end
-
-    def primary_or_first_role(roles)
-      roles.detect { |role| role == config.primary_role } || roles.first
-    end
-
-    def specified_roles
-      (specific_roles || config.roles) \
-        .select { |role| ((specific_hosts || config.all_hosts) & role.hosts).any? }
-    end
-
-    def specified_hosts
-      (specific_hosts || config.all_hosts) \
-        .select { |host| (specific_roles || config.roles).flat_map(&:hosts).include?(host) }
-    end
-end
--- a/lib/kamal/commands/accessory.rb
+++ b/lib/kamal/commands/accessory.rb
@@ -36,17 +36,17 @@ class Kamal::Commands::Accessory < Kamal::Commands::Base
  end


-  def logs(since: nil, lines: nil, grep: nil, grep_options: nil)
+  def logs(since: nil, lines: nil, grep: nil)
    pipe \
      docker(:logs, service_name, (" --since #{since}" if since), (" --tail #{lines}" if lines), "--timestamps", "2>&1"),
-      ("grep '#{grep}'#{" #{grep_options}" if grep_options}" if grep)
+      ("grep '#{grep}'" if grep)
  end

-  def follow_logs(grep: nil, grep_options: nil)
+  def follow_logs(grep: nil)
    run_over_ssh \
      pipe \
        docker(:logs, service_name, "--timestamps", "--tail", "10", "--follow", "2>&1"),
-        (%(grep "#{grep}"#{" #{grep_options}" if grep_options}) if grep)
+        (%(grep "#{grep}") if grep)
  end


--- a/lib/kamal/commands/app.rb
+++ b/lib/kamal/commands/app.rb
@@ -3,12 +3,11 @@ class Kamal::Commands::App < Kamal::Commands::Base

  ACTIVE_DOCKER_STATUSES = [ :running, :restarting ]

-  attr_reader :role, :host
+  attr_reader :role, :role

-  def initialize(config, role: nil, host: nil)
+  def initialize(config, role: nil)
    super(config)
    @role = role
-    @host = host
  end

  def run(hostname: nil)
@@ -19,7 +18,7 @@ class Kamal::Commands::App < Kamal::Commands::Base
      *([ "--hostname", hostname ] if hostname),
      "-e", "KAMAL_CONTAINER_NAME=\"#{container_name}\"",
      "-e", "KAMAL_VERSION=\"#{config.version}\"",
-      *role.env_args(host),
+      *role.env_args,
      *role.health_check_args,
      *role.logging_args,
      *config.volume_args,
@@ -50,7 +49,7 @@ class Kamal::Commands::App < Kamal::Commands::Base


  def current_running_container_id
-    current_running_container(format: "--quiet")
+    docker :ps, "--quiet", *filter_args(statuses: ACTIVE_DOCKER_STATUSES), "--latest"
  end

  def container_id_for_version(version, only_running: false)
@@ -58,24 +57,22 @@ class Kamal::Commands::App < Kamal::Commands::Base
  end

  def current_running_version
-    pipe \
-      current_running_container(format: "--format '{{.Names}}'"),
-      extract_version_from_name
+    list_versions("--latest", statuses: ACTIVE_DOCKER_STATUSES)
  end

  def list_versions(*docker_args, statuses: nil)
    pipe \
      docker(:ps, *filter_args(statuses: statuses), *docker_args, "--format", '"{{.Names}}"'),
-      extract_version_from_name
+      %(while read line; do echo ${line##{role.container_prefix}-}; done) # Extract SHA from "service-role-dest-SHA"
  end


  def make_env_directory
-    make_directory role.env(host).secrets_directory
+    make_directory role.env.secrets_directory
  end

  def remove_env_file
-    [ :rm, "-f", role.env(host).secrets_file ]
+    [ :rm, "-f", role.env.secrets_file ]
  end


@@ -84,33 +81,10 @@ class Kamal::Commands::App < Kamal::Commands::Base
      [ role.container_prefix, version || config.version ].compact.join("-")
    end

-    def latest_image_id
-      docker :image, :ls, *argumentize("--filter", "reference=#{config.latest_image}"), "--format", "'{{.ID}}'"
-    end
-
-    def current_running_container(format:)
-      pipe \
-        shell(chain(latest_image_container(format: format), latest_container(format: format))),
-        [ :head, "-1" ]
-    end
-
-    def latest_image_container(format:)
-      latest_container format: format, filters: [ "ancestor=$(#{latest_image_id.join(" ")})" ]
-    end
-
-    def latest_container(format:, filters: nil)
-      docker :ps, "--latest", *format, *filter_args(statuses: ACTIVE_DOCKER_STATUSES), argumentize("--filter", filters)
-    end
-
    def filter_args(statuses: nil)
      argumentize "--filter", filters(statuses: statuses)
    end

-    def extract_version_from_name
-      # Extract SHA from "service-role-dest-SHA"
-      %(while read line; do echo ${line##{role.container_prefix}-}; done)
-    end
-
    def filters(statuses: nil)
      [ "label=service=#{config.service}" ].tap do |filters|
        filters << "label=destination=#{config.destination}" if config.destination
--- a/lib/kamal/commands/app/assets.rb
+++ b/lib/kamal/commands/app/assets.rb
@@ -5,7 +5,7 @@ module Kamal::Commands::App::Assets
    combine \
      make_directory(role.asset_extracted_path),
      [ *docker(:stop, "-t 1", asset_container, "2> /dev/null"), "|| true" ],
-      docker(:run, "--name", asset_container, "--detach", "--rm", config.absolute_image, "sleep 1000000"),
+      docker(:run, "--name", asset_container, "--detach", "--rm", config.latest_image, "sleep 1000000"),
      docker(:cp, "-L", "#{asset_container}:#{role.asset_path}/.", role.asset_extracted_path),
      docker(:stop, "-t 1", asset_container),
      by: "&&"
--- a/lib/kamal/commands/app/containers.rb
+++ b/lib/kamal/commands/app/containers.rb
@@ -1,6 +1,4 @@
 module Kamal::Commands::App::Containers
-  DOCKER_HEALTH_LOG_FORMAT    = "'{{json .State.Health}}'"
-
  def list_containers
    docker :container, :ls, "--all", *filter_args
  end
@@ -22,10 +20,4 @@ module Kamal::Commands::App::Containers
  def remove_containers
    docker :container, :prune, "--force", *filter_args
  end
-
-  def container_health_log(version:)
-    pipe \
-      container_id_for(container_name: container_name(version)),
-      xargs(docker(:inspect, "--format", DOCKER_HEALTH_LOG_FORMAT))
-  end
 end
--- a/lib/kamal/commands/app/execution.rb
+++ b/lib/kamal/commands/app/execution.rb
@@ -1,29 +1,27 @@
 module Kamal::Commands::App::Execution
-  def execute_in_existing_container(*command, interactive: false, env:)
+  def execute_in_existing_container(*command, interactive: false)
    docker :exec,
      ("-it" if interactive),
-      *argumentize("--env", env),
      container_name,
      *command
  end

-  def execute_in_new_container(*command, interactive: false, env:)
+  def execute_in_new_container(*command, interactive: false)
    docker :run,
      ("-it" if interactive),
      "--rm",
-      *role&.env_args(host),
-      *argumentize("--env", env),
+      *role&.env_args,
      *config.volume_args,
      *role&.option_args,
      config.absolute_image,
      *command
  end

-  def execute_in_existing_container_over_ssh(*command,  env:)
-    run_over_ssh execute_in_existing_container(*command, interactive: true, env: env), host: host
+  def execute_in_existing_container_over_ssh(*command, host:)
+    run_over_ssh execute_in_existing_container(*command, interactive: true), host: host
  end

-  def execute_in_new_container_over_ssh(*command, env:)
-    run_over_ssh execute_in_new_container(*command, interactive: true, env: env), host: host
+  def execute_in_new_container_over_ssh(*command, host:)
+    run_over_ssh execute_in_new_container(*command, interactive: true), host: host
  end
 end
--- a/lib/kamal/commands/app/images.rb
+++ b/lib/kamal/commands/app/images.rb
@@ -7,7 +7,7 @@ module Kamal::Commands::App::Images
    docker :image, :prune, "--all", "--force", *filter_args
  end

-  def tag_latest_image
+  def tag_current_image_as_latest
    docker :tag, config.absolute_image, config.latest_image
  end
 end
--- a/lib/kamal/commands/app/logging.rb
+++ b/lib/kamal/commands/app/logging.rb
@@ -1,17 +1,17 @@
 module Kamal::Commands::App::Logging
-  def logs(version: nil, since: nil, lines: nil, grep: nil, grep_options: nil)
+  def logs(since: nil, lines: nil, grep: nil)
    pipe \
-      version ? container_id_for_version(version) : current_running_container_id,
+      current_running_container_id,
      "xargs docker logs#{" --since #{since}" if since}#{" --tail #{lines}" if lines} 2>&1",
-      ("grep '#{grep}'#{" #{grep_options}" if grep_options}" if grep)
+      ("grep '#{grep}'" if grep)
  end

-  def follow_logs(host:, lines: nil, grep: nil, grep_options: nil)
+  def follow_logs(host:, lines: nil, grep: nil)
    run_over_ssh \
      pipe(
        current_running_container_id,
        "xargs docker logs --timestamps#{" --tail #{lines}" if lines} --follow 2>&1",
-        (%(grep "#{grep}"#{" #{grep_options}" if grep_options}) if grep)
+        (%(grep "#{grep}") if grep)
      ),
      host: host
  end
--- a/lib/kamal/commands/auditor.rb
+++ b/lib/kamal/commands/auditor.rb
@@ -9,7 +9,7 @@ class Kamal::Commands::Auditor < Kamal::Commands::Base
  # Runs remotely
  def record(line, **details)
    append \
-      [ :echo, audit_tags(**details).except(:version, :service_version, :service).to_s, line ],
+      [ :echo, audit_tags(**details).except(:version, :service_version).to_s, line ],
      audit_log_file
  end

@@ -21,7 +21,7 @@ class Kamal::Commands::Auditor < Kamal::Commands::Base
    def audit_log_file
      file = [ config.service, config.destination, "audit.log" ].compact.join("-")

-      File.join(config.run_directory, file)
+      "#{config.run_directory}/#{file}"
    end

    def audit_tags(**details)
--- a/lib/kamal/commands/base.rb
+++ b/lib/kamal/commands/base.rb
@@ -3,6 +3,7 @@ module Kamal::Commands
    delegate :sensitive, :argumentize, to: Kamal::Utils

    DOCKER_HEALTH_STATUS_FORMAT = "'{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}'"
+    DOCKER_HEALTH_LOG_FORMAT    = "'{{json .State.Health}}'"

    attr_accessor :config

@@ -17,7 +18,7 @@ module Kamal::Commands
        elsif config.ssh.proxy && config.ssh.proxy.is_a?(Net::SSH::Proxy::Command)
          cmd << " -o ProxyCommand='#{config.ssh.proxy.command_line_template}'"
        end
-        cmd << " -t #{config.ssh.user}@#{host} -p #{config.ssh.port} '#{command.join(" ").gsub("'", "'\\\\''")}'"
+        cmd << " -t #{config.ssh.user}@#{host} -p #{config.ssh.port} '#{command.join(" ")}'"
      end
    end

@@ -70,17 +71,13 @@ module Kamal::Commands
      end

      def shell(command)
-        [ :sh, "-c", "'#{command.flatten.join(" ").gsub("'", "'\\\\''")}'" ]
+        [ :sh, "-c", "'#{command.flatten.join(" ").gsub("'", "'\\''")}'" ]
      end

      def docker(*args)
        args.compact.unshift :docker
      end

-      def git(*args, path: nil)
-        [ :git, *([ "-C", path ] if path), *args.compact ]
-      end
-
      def tags(**details)
        Kamal::Tags.from_config(config, **details)
      end
--- a/lib/kamal/commands/builder.rb
+++ b/lib/kamal/commands/builder.rb
@@ -1,32 +1,24 @@
 require "active_support/core_ext/string/filters"

 class Kamal::Commands::Builder < Kamal::Commands::Base
-  delegate :create, :remove, :push, :clean, :pull, :info, :context_hosts, :config_context_hosts, :validate_image,
-           :first_mirror, to: :target
-
-  include Clone
+  delegate :create, :remove, :push, :clean, :pull, :info, :validate_image, to: :target

  def name
    target.class.to_s.remove("Kamal::Commands::Builder::").underscore.inquiry
  end

  def target
-    if config.builder.multiarch?
-      if config.builder.remote?
-        if config.builder.local?
-          multiarch_remote
-        else
-          native_remote
-        end
-      else
-        multiarch
-      end
+    case
+    when !config.builder.multiarch? && !config.builder.cached?
+      native
+    when !config.builder.multiarch? && config.builder.cached?
+      native_cached
+    when config.builder.local? && config.builder.remote?
+      multiarch_remote
+    when config.builder.remote?
+      native_remote
    else
-      if config.builder.cached?
-        native_cached
-      else
-        native
-      end
+      multiarch
    end
  end

--- a/lib/kamal/commands/builder/base.rb
+++ b/lib/kamal/commands/builder/base.rb
@@ -2,10 +2,8 @@
 class Kamal::Commands::Builder::Base < Kamal::Commands::Base
  class BuilderError < StandardError; end

-  ENDPOINT_DOCKER_HOST_INSPECT = "'{{.Endpoints.docker.Host}}'"
-
  delegate :argumentize, to: Kamal::Utils
-  delegate :args, :secrets, :dockerfile, :target, :local_arch, :local_host, :remote_arch, :remote_host, :cache_from, :cache_to, :ssh, to: :builder_config
+  delegate :args, :secrets, :dockerfile, :local_arch, :local_host, :remote_arch, :remote_host, :cache_from, :cache_to, :ssh, to: :builder_config

  def clean
    docker :image, :rm, "--force", config.absolute_image
@@ -16,7 +14,7 @@ class Kamal::Commands::Builder::Base < Kamal::Commands::Base
  end

  def build_options
-    [ *build_tags, *build_cache, *build_labels, *build_args, *build_secrets, *build_dockerfile, *build_target, *build_ssh ]
+    [ *build_tags, *build_cache, *build_labels, *build_args, *build_secrets, *build_dockerfile, *build_ssh ]
  end

  def build_context
@@ -32,17 +30,6 @@ class Kamal::Commands::Builder::Base < Kamal::Commands::Base
      )
  end

-  def context_hosts
-    :true
-  end
-
-  def config_context_hosts
-    []
-  end
-
-  def first_mirror
-    docker(:info, "--format '{{index .RegistryConfig.Mirrors 0}}'")
-  end

  private
    def build_tags
@@ -76,10 +63,6 @@ class Kamal::Commands::Builder::Base < Kamal::Commands::Base
      end
    end

-    def build_target
-      argumentize "--target", target if target.present?
-    end
-
    def build_ssh
      argumentize "--ssh", ssh if ssh.present?
    end
@@ -87,8 +70,4 @@ class Kamal::Commands::Builder::Base < Kamal::Commands::Base
    def builder_config
      config.builder
    end
-
-    def context_host(builder_name)
-      docker :context, :inspect, builder_name, "--format", ENDPOINT_DOCKER_HOST_INSPECT
-    end
 end
--- a/lib/kamal/commands/builder/clone.rb
+++ b/lib/kamal/commands/builder/clone.rb
@@ -1,29 +0,0 @@
-module Kamal::Commands::Builder::Clone
-  extend ActiveSupport::Concern
-
-  included do
-    delegate :clone_directory, :build_directory, to: :"config.builder"
-  end
-
-  def clone
-    git :clone, Kamal::Git.root, "--recurse-submodules", path: clone_directory
-  end
-
-  def clone_reset_steps
-    [
-      git(:remote, "set-url", :origin, Kamal::Git.root, path: build_directory),
-      git(:fetch, :origin, path: build_directory),
-      git(:reset, "--hard", Kamal::Git.revision, path: build_directory),
-      git(:clean, "-fdx", path: build_directory),
-      git(:submodule, :update, "--init", path: build_directory)
-    ]
-  end
-
-  def clone_status
-    git :status, "--porcelain", path: build_directory
-  end
-
-  def clone_revision
-    git :"rev-parse", :HEAD, path: build_directory
-  end
-end
--- a/lib/kamal/commands/builder/multiarch.rb
+++ b/lib/kamal/commands/builder/multiarch.rb
@@ -7,12 +7,6 @@ class Kamal::Commands::Builder::Multiarch < Kamal::Commands::Builder::Base
    docker :buildx, :rm, builder_name
  end

-  def info
-    combine \
-      docker(:context, :ls),
-      docker(:buildx, :ls)
-  end
-
  def push
    docker :buildx, :build,
      "--push",
@@ -22,8 +16,10 @@ class Kamal::Commands::Builder::Multiarch < Kamal::Commands::Builder::Base
      build_context
  end

-  def context_hosts
-    docker :buildx, :inspect, builder_name, "> /dev/null"
+  def info
+    combine \
+      docker(:context, :ls),
+      docker(:buildx, :ls)
  end

  private
--- a/lib/kamal/commands/builder/multiarch/remote.rb
+++ b/lib/kamal/commands/builder/multiarch/remote.rb
@@ -12,16 +12,6 @@ class Kamal::Commands::Builder::Multiarch::Remote < Kamal::Commands::Builder::Mu
      super
  end

-  def context_hosts
-    chain \
-      context_host(builder_name_with_arch(local_arch)),
-      context_host(builder_name_with_arch(remote_arch))
-  end
-
-  def config_context_hosts
-    [ local_host, remote_host ].compact
-  end
-
  private
    def builder_name
      super + "-remote"
@@ -58,8 +48,4 @@ class Kamal::Commands::Builder::Multiarch::Remote < Kamal::Commands::Builder::Mu
    def remove_context(arch)
      docker :context, :rm, builder_name_with_arch(arch)
    end
-
-    def platform_names
-      "linux/#{local_arch},linux/#{remote_arch}"
-    end
 end
--- a/lib/kamal/commands/builder/native.rb
+++ b/lib/kamal/commands/builder/native.rb
@@ -7,14 +7,14 @@ class Kamal::Commands::Builder::Native < Kamal::Commands::Builder::Base
    # No-op on native without cache
  end

-  def info
-    # No-op on native
-  end
-
  def push
    combine \
      docker(:build, *build_options, build_context),
      docker(:push, config.absolute_image),
      docker(:push, config.latest_image)
  end
+
+  def info
+    # No-op on native
+  end
 end
--- a/lib/kamal/commands/builder/native/cached.rb
+++ b/lib/kamal/commands/builder/native/cached.rb
@@ -1,6 +1,6 @@
 class Kamal::Commands::Builder::Native::Cached < Kamal::Commands::Builder::Native
  def create
-    docker :buildx, :create, "--name", builder_name, "--use", "--driver=docker-container"
+    docker :buildx, :create, "--use", "--driver=docker-container"
  end

  def remove
@@ -13,13 +13,4 @@ class Kamal::Commands::Builder::Native::Cached < Kamal::Commands::Builder::Nativ
      *build_options,
      build_context
  end
-
-  def context_hosts
-    docker :buildx, :inspect, builder_name, "> /dev/null"
-  end
-
-  private
-    def builder_name
-      "kamal-#{config.service}-native-cached"
-    end
 end
--- a/lib/kamal/commands/builder/native/remote.rb
+++ b/lib/kamal/commands/builder/native/remote.rb
@@ -11,29 +11,21 @@ class Kamal::Commands::Builder::Native::Remote < Kamal::Commands::Builder::Nativ
      remove_buildx
  end

+  def push
+    docker :buildx, :build,
+      "--push",
+      "--platform", platform,
+      "--builder", builder_name,
+      *build_options,
+      build_context
+  end
+
  def info
    chain \
      docker(:context, :ls),
      docker(:buildx, :ls)
  end

-  def push
-    docker :buildx, :build,
-    "--push",
-    "--platform", platform,
-    "--builder", builder_name,
-    *build_options,
-    build_context
-  end
-
-  def context_hosts
-    context_host(builder_name_with_arch)
-  end
-
-  def config_context_hosts
-    [ remote_host ]
-  end
-

  private
    def builder_name
--- a/lib/kamal/commands/healthcheck.rb
+++ b/lib/kamal/commands/healthcheck.rb
@@ -0,0 +1,59 @@
+class Kamal::Commands::Healthcheck < Kamal::Commands::Base
+  def run
+    primary = config.role(config.primary_role)
+
+    docker :run,
+      "--detach",
+      "--name", container_name_with_version,
+      "--publish", "#{exposed_port}:#{config.healthcheck["port"]}",
+      "--label", "service=#{config.healthcheck_service}",
+      "-e", "KAMAL_CONTAINER_NAME=\"#{config.healthcheck_service}\"",
+      *primary.env_args,
+      *primary.health_check_args(cord: false),
+      *config.volume_args,
+      *primary.option_args,
+      config.absolute_image,
+      primary.cmd
+  end
+
+  def status
+    pipe container_id, xargs(docker(:inspect, "--format", DOCKER_HEALTH_STATUS_FORMAT))
+  end
+
+  def container_health_log
+    pipe container_id, xargs(docker(:inspect, "--format", DOCKER_HEALTH_LOG_FORMAT))
+  end
+
+  def logs
+    pipe container_id, xargs(docker(:logs, "--tail", log_lines, "2>&1"))
+  end
+
+  def stop
+    pipe container_id, xargs(docker(:stop))
+  end
+
+  def remove
+    pipe container_id, xargs(docker(:container, :rm))
+  end
+
+  private
+    def container_name_with_version
+      "#{config.healthcheck_service}-#{config.version}"
+    end
+
+    def container_id
+      container_id_for(container_name: container_name_with_version)
+    end
+
+    def health_url
+      "http://localhost:#{exposed_port}#{config.healthcheck["path"]}"
+    end
+
+    def exposed_port
+      config.healthcheck["exposed_port"]
+    end
+
+    def log_lines
+      config.healthcheck["log_lines"]
+    end
+end
--- a/lib/kamal/commands/hook.rb
+++ b/lib/kamal/commands/hook.rb
@@ -9,6 +9,6 @@ class Kamal::Commands::Hook < Kamal::Commands::Base

  private
    def hook_file(hook)
-      File.join(config.hooks_path, hook)
+      "#{config.hooks_path}/#{hook}"
    end
 end
--- a/lib/kamal/commands/lock.rb
+++ b/lib/kamal/commands/lock.rb
@@ -21,10 +21,6 @@ class Kamal::Commands::Lock < Kamal::Commands::Base
      read_lock_details
  end

-  def ensure_locks_directory
-    [ :mkdir, "-p", locks_dir ]
-  end
-
  private
    def write_lock_details(message, version)
      write \
@@ -44,18 +40,12 @@ class Kamal::Commands::Lock < Kamal::Commands::Base
        "/dev/null"
    end

-    def locks_dir
-      File.join(config.run_directory, "locks")
-    end
-
    def lock_dir
-      dir_name = [ config.service, config.destination ].compact.join("-")
-
-      File.join(locks_dir, dir_name)
+      "#{config.run_directory}/lock-#{config.service}"
    end

    def lock_details_file
-      File.join(lock_dir, "details")
+      [ lock_dir, :details ].join("/")
    end

    def lock_details(message, version)
--- a/lib/kamal/commands/registry.rb
+++ b/lib/kamal/commands/registry.rb
@@ -3,12 +3,21 @@ class Kamal::Commands::Registry < Kamal::Commands::Base

  def login
    docker :login,
-      registry.server,
-      "-u", sensitive(Kamal::Utils.escape_shell_value(registry.username)),
-      "-p", sensitive(Kamal::Utils.escape_shell_value(registry.password))
+      registry["server"],
+      "-u", sensitive(Kamal::Utils.escape_shell_value(lookup("username"))),
+      "-p", sensitive(Kamal::Utils.escape_shell_value(lookup("password")))
  end

  def logout
-    docker :logout, registry.server
+    docker :logout, registry["server"]
  end
+
+  private
+    def lookup(key)
+      if registry[key].is_a?(Array)
+        ENV.fetch(registry[key].first).dup
+      else
+        registry[key]
+      end
+    end
 end
--- a/lib/kamal/commands/traefik.rb
+++ b/lib/kamal/commands/traefik.rb
@@ -1,6 +1,19 @@
 class Kamal::Commands::Traefik < Kamal::Commands::Base
  delegate :argumentize, :optionize, to: Kamal::Utils
-  delegate :port, :publish?, :labels, :env, :image, :options, :args, to: :"config.traefik"
+
+  DEFAULT_IMAGE = "traefik:v2.10"
+  CONTAINER_PORT = 80
+  DEFAULT_ARGS = {
+    "log.level" => "DEBUG"
+  }
+  DEFAULT_LABELS = {
+    # These ensure we serve a 502 rather than a 404 if no containers are available
+    "traefik.http.routers.catchall.entryPoints" => "http",
+    "traefik.http.routers.catchall.rule" => "PathPrefix(`/`)",
+    "traefik.http.routers.catchall.service" => "unavailable",
+    "traefik.http.routers.catchall.priority" => 1,
+    "traefik.http.services.unavailable.loadbalancer.server.port" => "0"
+  }

  def run
    docker :run, "--name traefik",
@@ -33,16 +46,16 @@ class Kamal::Commands::Traefik < Kamal::Commands::Base
    docker :ps, "--filter", "name=^traefik$"
  end

-  def logs(since: nil, lines: nil, grep: nil, grep_options: nil)
+  def logs(since: nil, lines: nil, grep: nil)
    pipe \
      docker(:logs, "traefik", (" --since #{since}" if since), (" --tail #{lines}" if lines), "--timestamps", "2>&1"),
-      ("grep '#{grep}'#{" #{grep_options}" if grep_options}" if grep)
+      ("grep '#{grep}'" if grep)
  end

-  def follow_logs(host:, grep: nil, grep_options: nil)
+  def follow_logs(host:, grep: nil)
    run_over_ssh pipe(
      docker(:logs, "traefik", "--timestamps", "--tail", "10", "--follow", "2>&1"),
-      (%(grep "#{grep}"#{" #{grep_options}" if grep_options}) if grep)
+      (%(grep "#{grep}") if grep)
    ).join(" "), host: host
  end

@@ -54,6 +67,16 @@ class Kamal::Commands::Traefik < Kamal::Commands::Base
    docker :image, :prune, "--all", "--force", "--filter", "label=org.opencontainers.image.title=Traefik"
  end

+  def port
+    "#{host_port}:#{CONTAINER_PORT}"
+  end
+
+  def env
+    Kamal::Configuration::Env.from_config \
+      config: config.traefik.fetch("env", {}),
+      secrets_file: File.join(config.host_env_directory, "traefik", "traefik.env")
+  end
+
  def make_env_directory
    make_directory(env.secrets_directory)
  end
@@ -62,18 +85,9 @@ class Kamal::Commands::Traefik < Kamal::Commands::Base
    [ :rm, "-f", env.secrets_file ]
  end

-  def cleanup_kamal_proxy
-    chain \
-      docker(:container, :stop, "kamal-proxy"),
-      combine(
-        docker(:container, :prune, "--force", "--filter", "label=org.opencontainers.image.title=kamal-proxy"),
-        docker(:image, :prune, "--all", "--force", "--filter", "label=org.opencontainers.image.title=kamal-proxy")
-      )
-  end
-
  private
    def publish_args
-      argumentize "--publish", port if publish?
+      argumentize "--publish", port unless config.traefik["publish"] == false
    end

    def label_args
@@ -84,11 +98,27 @@ class Kamal::Commands::Traefik < Kamal::Commands::Base
      env.args
    end

+    def labels
+      DEFAULT_LABELS.merge(config.traefik["labels"] || {})
+    end
+
+    def image
+      config.traefik.fetch("image") { DEFAULT_IMAGE }
+    end
+
    def docker_options_args
-      optionize(options)
+      optionize(config.traefik["options"] || {})
    end

    def cmd_option_args
-      optionize args, with: "="
+      if args = config.traefik["args"]
+        optionize DEFAULT_ARGS.merge(args), with: "="
+      else
+        optionize DEFAULT_ARGS, with: "="
+      end
+    end
+
+    def host_port
+      config.traefik["host_port"] || CONTAINER_PORT
    end
 end
--- a/lib/kamal/configuration.rb
+++ b/lib/kamal/configuration.rb
@@ -1,19 +1,15 @@
 require "active_support/ordered_options"
 require "active_support/core_ext/string/inquiry"
 require "active_support/core_ext/module/delegation"
-require "active_support/core_ext/hash/keys"
 require "pathname"
 require "erb"
 require "net/ssh/proxy/jump"

 class Kamal::Configuration
-  delegate :service, :image, :labels, :stop_wait_time, :hooks_path, to: :raw_config, allow_nil: true
+  delegate :service, :image, :servers, :labels, :registry, :stop_wait_time, :hooks_path, :logging, to: :raw_config, allow_nil: true
  delegate :argumentize, :optionize, to: Kamal::Utils

  attr_reader :destination, :raw_config
-  attr_reader :accessories, :boot, :builder, :env, :healthcheck, :logging, :traefik, :servers, :ssh, :sshkit, :registry
-
-  include Validation

  class << self
    def create_from(config_file:, destination: nil, version: nil)
@@ -46,29 +42,7 @@ class Kamal::Configuration
    @raw_config = ActiveSupport::InheritableOptions.new(raw_config)
    @destination = destination
    @declared_version = version
-
-    validate! raw_config, example: validation_yml.symbolize_keys, context: "", with: Kamal::Configuration::Validator::Configuration
-
-    # Eager load config to validate it, these are first as they have dependencies later on
-    @servers = Servers.new(config: self)
-    @registry = Registry.new(config: self)
-
-    @accessories = @raw_config.accessories&.keys&.collect { |name| Accessory.new(name, config: self) } || []
-    @boot = Boot.new(config: self)
-    @builder = Builder.new(config: self)
-    @env = Env.new(config: @raw_config.env || {})
-
-    @healthcheck = Healthcheck.new(healthcheck_config: @raw_config.healthcheck)
-    @logging = Logging.new(logging_config: @raw_config.logging)
-    @traefik = Traefik.new(config: self)
-    @ssh = Ssh.new(config: self)
-    @sshkit = Sshkit.new(config: self)
-
-    ensure_destination_if_required
-    ensure_required_keys_present
-    ensure_valid_kamal_version
-    ensure_retain_containers_valid
-    ensure_valid_service_name
+    valid? if validate
  end


@@ -97,20 +71,24 @@ class Kamal::Configuration


  def roles
-    servers.roles
+    @roles ||= role_names.collect { |role_name| Role.new(role_name, config: self) }
  end

  def role(name)
    roles.detect { |r| r.name == name.to_s }
  end

+  def accessories
+    @accessories ||= raw_config.accessories&.keys&.collect { |name| Kamal::Configuration::Accessory.new(name, config: self) } || []
+  end
+
  def accessory(name)
    accessories.detect { |a| a.name == name.to_s }
  end


  def all_hosts
-    (roles + accessories).flat_map(&:hosts).uniq
+    roles.flat_map(&:hosts).uniq
  end

  def primary_host
@@ -142,7 +120,7 @@ class Kamal::Configuration
  end

  def repository
-    [ registry.server, image ].compact.join("/")
+    [ raw_config.registry["server"], image ].compact.join("/")
  end

  def absolute_image
@@ -150,11 +128,7 @@ class Kamal::Configuration
  end

  def latest_image
-    "#{repository}:#{latest_tag}"
-  end
-
-  def latest_tag
-    [ "latest", *destination ].join("-")
+    "#{repository}:#{[ "latest", *destination ].join("-")}"
  end

  def service_with_version
@@ -179,10 +153,40 @@ class Kamal::Configuration
  end

  def logging_args
-    logging.args
+    if logging.present?
+      optionize({ "log-driver" => logging["driver"] }.compact) +
+        argumentize("--log-opt", logging["options"])
+    else
+      argumentize("--log-opt", { "max-size" => "10m" })
+    end
  end


+  def boot
+    Kamal::Configuration::Boot.new(config: self)
+  end
+
+  def builder
+    Kamal::Configuration::Builder.new(config: self)
+  end
+
+  def traefik
+    raw_config.traefik || {}
+  end
+
+  def ssh
+    Kamal::Configuration::Ssh.new(config: self)
+  end
+
+  def sshkit
+    Kamal::Configuration::Sshkit.new(config: self)
+  end
+
+
+  def healthcheck
+    { "path" => "/up", "port" => 3000, "max_attempts" => 7, "exposed_port" => 3999, "cord" => "/tmp/kamal-cord", "log_lines" => 50 }.merge(raw_config.healthcheck || {})
+  end
+
  def healthcheck_service
    [ "healthcheck", service, destination ].compact.join("-")
  end
@@ -218,21 +222,17 @@ class Kamal::Configuration


  def host_env_directory
-    File.join(run_directory, "env")
+    "#{run_directory}/env"
  end

-  def env_tags
-    @env_tags ||= if (tags = raw_config.env["tags"])
-      tags.collect { |name, config| Env::Tag.new(name, config: config) }
-    else
-      []
-    end
+  def env
+    raw_config.env || {}
  end

-  def env_tag(name)
-    env_tags.detect { |t| t.name == name.to_s }
-  end

+  def valid?
+    ensure_destination_if_required && ensure_required_keys_present && ensure_valid_kamal_version && ensure_retain_containers_valid && ensure_valid_service_name
+  end

  def to_h
    {
@@ -249,10 +249,11 @@ class Kamal::Configuration
      builder: builder.to_h,
      accessories: raw_config.accessories,
      logging: logging_args,
-      healthcheck: healthcheck.to_h
+      healthcheck: healthcheck
    }.compact
  end

+
  private
    # Will raise ArgumentError if any required config keys are missing
    def ensure_destination_if_required
@@ -265,21 +266,29 @@ class Kamal::Configuration

    def ensure_required_keys_present
      %i[ service image registry servers ].each do |key|
-        raise Kamal::ConfigurationError, "Missing required configuration for #{key}" unless raw_config[key].present?
+        raise ArgumentError, "Missing required configuration for #{key}" unless raw_config[key].present?
      end

-      unless role(primary_role_name).present?
-        raise Kamal::ConfigurationError, "The primary_role #{primary_role_name} isn't defined"
+      if raw_config.registry["username"].blank?
+        raise ArgumentError, "You must specify a username for the registry in config/deploy.yml"
+      end
+
+      if raw_config.registry["password"].blank?
+        raise ArgumentError, "You must specify a password for the registry in config/deploy.yml (or set the ENV variable if that's used)"
+      end
+
+      unless role_names.include?(primary_role_name)
+        raise ArgumentError, "The primary_role #{primary_role_name} isn't defined"
      end

      if primary_role.hosts.empty?
-        raise Kamal::ConfigurationError, "No servers specified for the #{primary_role.name} primary_role"
+        raise ArgumentError, "No servers specified for the #{primary_role.name} primary_role"
      end

      unless allow_empty_roles?
        roles.each do |role|
          if role.hosts.empty?
-            raise Kamal::ConfigurationError, "No servers specified for the #{role.name} role. You can ignore this with allow_empty_roles: true"
+            raise ArgumentError, "No servers specified for the #{role.name} role. You can ignore this with allow_empty_roles: true"
          end
        end
      end
@@ -288,21 +297,21 @@ class Kamal::Configuration
    end

    def ensure_valid_service_name
-      raise Kamal::ConfigurationError, "Service name can only include alphanumeric characters, hyphens, and underscores" unless raw_config[:service] =~ /^[a-z0-9_-]+$/i
+      raise ArgumentError, "Service name can only include alphanumeric characters, hyphens, and underscores" unless raw_config[:service] =~ /^[a-z0-9_-]+$/

      true
    end

    def ensure_valid_kamal_version
      if minimum_version && Gem::Version.new(minimum_version) > Gem::Version.new(Kamal::VERSION)
-        raise Kamal::ConfigurationError, "Current version is #{Kamal::VERSION}, minimum required is #{minimum_version}"
+        raise ArgumentError, "Current version is #{Kamal::VERSION}, minimum required is #{minimum_version}"
      end

      true
    end

    def ensure_retain_containers_valid
-      raise Kamal::ConfigurationError, "Must retain at least 1 container" if retain_containers < 1
+      raise ArgumentError, "Must retain at least 1 container" if retain_containers < 1

      true
    end
@@ -315,10 +324,7 @@ class Kamal::Configuration
    def git_version
      @git_version ||=
        if Kamal::Git.used?
-          if Kamal::Git.uncommitted_changes.present? && !builder.git_clone?
-            uncommitted_suffix = "_uncommitted_#{SecureRandom.hex(8)}"
-          end
-          [ Kamal::Git.revision, uncommitted_suffix ].compact.join
+          [ Kamal::Git.revision, Kamal::Git.uncommitted_changes.present? ? "_uncommitted_#{SecureRandom.hex(8)}" : "" ].join
        else
          raise "Can't use commit hash as version, no git repository found in #{Dir.pwd}"
        end
--- a/lib/kamal/configuration/accessory.rb
+++ b/lib/kamal/configuration/accessory.rb
@@ -1,39 +1,30 @@
 class Kamal::Configuration::Accessory
-  include Kamal::Configuration::Validation
-
  delegate :argumentize, :optionize, to: Kamal::Utils

-  attr_reader :name, :accessory_config, :env
+  attr_accessor :name, :specifics

  def initialize(name, config:)
-    @name, @config, @accessory_config = name.inquiry, config, config.raw_config["accessories"][name]
-
-    validate! \
-      accessory_config,
-      example: validation_yml["accessories"]["mysql"],
-      context: "accessories/#{name}",
-      with: Kamal::Configuration::Validator::Accessory
-
-    @env = Kamal::Configuration::Env.new \
-      config: accessory_config.fetch("env", {}),
-      secrets_file: File.join(config.host_env_directory, "accessories", "#{service_name}.env"),
-      context: "accessories/#{name}/env"
+    @name, @config, @specifics = name.inquiry, config, config.raw_config["accessories"][name]
  end

  def service_name
-    accessory_config["service"] || "#{config.service}-#{name}"
+    specifics["service"] || "#{config.service}-#{name}"
  end

  def image
-    accessory_config["image"]
+    specifics["image"]
  end

  def hosts
+    if (specifics.keys & [ "host", "hosts", "roles" ]).size != 1
+      raise ArgumentError, "Specify one of `host`, `hosts` or `roles` for accessory `#{name}`"
+    end
+
    hosts_from_host || hosts_from_hosts || hosts_from_roles
  end

  def port
-    if port = accessory_config["port"]&.to_s
+    if port = specifics["port"]&.to_s
      port.include?(":") ? port : "#{port}:#{port}"
    end
  end
@@ -43,26 +34,32 @@ class Kamal::Configuration::Accessory
  end

  def labels
-    default_labels.merge(accessory_config["labels"] || {})
+    default_labels.merge(specifics["labels"] || {})
  end

  def label_args
    argumentize "--label", labels
  end

+  def env
+    Kamal::Configuration::Env.from_config \
+      config: specifics.fetch("env", {}),
+      secrets_file: File.join(config.host_env_directory, "accessories", "#{service_name}.env")
+  end
+
  def env_args
    env.args
  end

  def files
-    accessory_config["files"]&.to_h do |local_to_remote_mapping|
+    specifics["files"]&.to_h do |local_to_remote_mapping|
      local_file, remote_file = local_to_remote_mapping.split(":")
      [ expand_local_file(local_file), expand_remote_file(remote_file) ]
    end || {}
  end

  def directories
-    accessory_config["directories"]&.to_h do |host_to_container_mapping|
+    specifics["directories"]&.to_h do |host_to_container_mapping|
      host_path, container_path = host_to_container_mapping.split(":")
      [ expand_host_path(host_path), container_path ]
    end || {}
@@ -77,7 +74,7 @@ class Kamal::Configuration::Accessory
  end

  def option_args
-    if args = accessory_config["options"]
+    if args = specifics["options"]
      optionize args
    else
      []
@@ -85,7 +82,7 @@ class Kamal::Configuration::Accessory
  end

  def cmd
-    accessory_config["cmd"]
+    specifics["cmd"]
  end

  private
@@ -119,25 +116,25 @@ class Kamal::Configuration::Accessory
    end

    def specific_volumes
-      accessory_config["volumes"] || []
+      specifics["volumes"] || []
    end

    def remote_files_as_volumes
-      accessory_config["files"]&.collect do |local_to_remote_mapping|
+      specifics["files"]&.collect do |local_to_remote_mapping|
        _, remote_file = local_to_remote_mapping.split(":")
        "#{service_data_directory + remote_file}:#{remote_file}"
      end || []
    end

    def remote_directories_as_volumes
-      accessory_config["directories"]&.collect do |host_to_container_mapping|
+      specifics["directories"]&.collect do |host_to_container_mapping|
        host_path, container_path = host_to_container_mapping.split(":")
        [ expand_host_path(host_path), container_path ].join(":")
      end || []
    end

    def expand_host_path(host_path)
-      absolute_path?(host_path) ? host_path : File.join(service_data_directory, host_path)
+      absolute_path?(host_path) ? host_path : "#{service_data_directory}/#{host_path}"
    end

    def absolute_path?(path)
@@ -149,16 +146,30 @@ class Kamal::Configuration::Accessory
    end

    def hosts_from_host
-      [ accessory_config["host"] ] if accessory_config.key?("host")
+      if specifics.key?("host")
+        host = specifics["host"]
+        if host
+          [ host ]
+        else
+          raise ArgumentError, "Missing host for accessory `#{name}`"
+        end
+      end
    end

    def hosts_from_hosts
-      accessory_config["hosts"] if accessory_config.key?("hosts")
+      if specifics.key?("hosts")
+        hosts = specifics["hosts"]
+        if hosts.is_a?(Array)
+          hosts
+        else
+          raise ArgumentError, "Hosts should be an Array for accessory `#{name}`"
+        end
+      end
    end

    def hosts_from_roles
-      if accessory_config.key?("roles")
-        accessory_config["roles"].flat_map { |role| config.role(role).hosts }
+      if specifics.key?("roles")
+        specifics["roles"].flat_map { |role| config.role(role).hosts }
      end
    end
 end
--- a/lib/kamal/configuration/boot.rb
+++ b/lib/kamal/configuration/boot.rb
@@ -1,25 +1,20 @@
 class Kamal::Configuration::Boot
-  include Kamal::Configuration::Validation
-
-  attr_reader :boot_config, :host_count
-
  def initialize(config:)
-    @boot_config = config.raw_config.boot || {}
+    @options = config.raw_config.boot || {}
    @host_count = config.all_hosts.count
-    validate! boot_config
  end

  def limit
-    limit = boot_config["limit"]
+    limit = @options["limit"]

    if limit.to_s.end_with?("%")
-      [ host_count * limit.to_i / 100, 1 ].max
+      [ @host_count * limit.to_i / 100, 1 ].max
    else
      limit
    end
  end

  def wait
-    boot_config["wait"]
+    @options["wait"]
  end
 end
--- a/lib/kamal/configuration/builder.rb
+++ b/lib/kamal/configuration/builder.rb
@@ -1,79 +1,67 @@
 class Kamal::Configuration::Builder
-  include Kamal::Configuration::Validation
-
-  attr_reader :config, :builder_config
-  delegate :image, :service, to: :config
-  delegate :server, to: :"config.registry"
-
  def initialize(config:)
-    @config = config
-    @builder_config = config.raw_config.builder || {}
+    @options = config.raw_config.builder || {}
    @image = config.image
-    @server = config.registry.server
-    @service = config.service
+    @server = config.registry["server"]

-    validate! builder_config, with: Kamal::Configuration::Validator::Builder
+    valid?
  end

  def to_h
-    builder_config
+    @options
  end

  def multiarch?
-    builder_config["multiarch"] != false
+    @options["multiarch"] != false
  end

  def local?
-    !!builder_config["local"]
+    !!@options["local"]
  end

  def remote?
-    !!builder_config["remote"]
+    !!@options["remote"]
  end

  def cached?
-    !!builder_config["cache"]
+    !!@options["cache"]
  end

  def args
-    builder_config["args"] || {}
+    @options["args"] || {}
  end

  def secrets
-    builder_config["secrets"] || []
+    @options["secrets"] || []
  end

  def dockerfile
-    builder_config["dockerfile"] || "Dockerfile"
-  end
-
-  def target
-    builder_config["target"]
+    @options["dockerfile"] || "Dockerfile"
  end

  def context
-    builder_config["context"] || "."
+    @options["context"] || "."
  end

  def local_arch
-    builder_config["local"]["arch"] if local?
+    @options["local"]["arch"] if local?
  end

  def local_host
-    builder_config["local"]["host"] if local?
+    @options["local"]["host"] if local?
  end

  def remote_arch
-    builder_config["remote"]["arch"] if remote?
+    @options["remote"]["arch"] if remote?
  end

  def remote_host
-    builder_config["remote"]["host"] if remote?
+    @options["remote"]["host"] if remote?
  end

  def cache_from
    if cached?
-      case builder_config["cache"]["type"]
+      case @options["cache"]["type"]
      when "gha"
        cache_from_config_for_gha
      when "registry"
@@ -84,7 +72,7 @@ class Kamal::Configuration::Builder

  def cache_to
    if cached?
-      case builder_config["cache"]["type"]
+      case @options["cache"]["type"]
      when "gha"
        cache_to_config_for_gha
      when "registry"
@@ -94,33 +82,22 @@ class Kamal::Configuration::Builder
  end

  def ssh
-    builder_config["ssh"]
-  end
-
-  def git_clone?
-    Kamal::Git.used? && builder_config["context"].nil?
-  end
-
-  def clone_directory
-    @clone_directory ||= File.join Dir.tmpdir, "kamal-clones", [ service, pwd_sha ].compact.join("-")
-  end
-
-  def build_directory
-    @build_directory ||=
-      if git_clone?
-        File.join clone_directory, repo_basename, repo_relative_pwd
-      else
-        "."
-      end
+    @options["ssh"]
  end

  private
+    def valid?
+      if @options["cache"] && @options["cache"]["type"]
+        raise ArgumentError, "Invalid cache type: #{@options["cache"]["type"]}" unless [ "gha", "registry" ].include?(@options["cache"]["type"])
+      end
+    end
+
    def cache_image
-      builder_config["cache"]&.fetch("image", nil) || "#{image}-build-cache"
+      @options["cache"]&.fetch("image", nil) || "#{@image}-build-cache"
    end

    def cache_image_ref
-      [ server, cache_image ].compact.join("/")
+      [ @server, cache_image ].compact.join("/")
    end

    def cache_from_config_for_gha
@@ -132,22 +109,10 @@ class Kamal::Configuration::Builder
    end

    def cache_to_config_for_gha
-      [ "type=gha", builder_config["cache"]&.fetch("options", nil) ].compact.join(",")
+      [ "type=gha", @options["cache"]&.fetch("options", nil) ].compact.join(",")
    end

    def cache_to_config_for_registry
-      [ "type=registry", builder_config["cache"]&.fetch("options", nil), "ref=#{cache_image_ref}" ].compact.join(",")
-    end
-
-    def repo_basename
-      File.basename(Kamal::Git.root)
-    end
-
-    def repo_relative_pwd
-      Dir.pwd.delete_prefix(Kamal::Git.root)
-    end
-
-    def pwd_sha
-      Digest::SHA256.hexdigest(Dir.pwd)[0..12]
+      [ "type=registry", @options["cache"]&.fetch("options", nil), "ref=#{cache_image_ref}" ].compact.join(",")
    end
 end
--- a/lib/kamal/configuration/docs/accessory.yml
+++ b/lib/kamal/configuration/docs/accessory.yml
@@ -1,90 +0,0 @@
-# Accessories
-#
-# Accessories can be booted on a single host, a list of hosts, or on specific roles.
-# The hosts do not need to be defined in the Kamal servers configuration.
-#
-# Accessories are managed separately from the main service - they are not updated
-# when you deploy and they do not have zero-downtime deployments.
-#
-# Run `kamal accessory boot <accessory>` to boot an accessory.
-# See `kamal accessory --help` for more information.
-
-# Configuring accessories
-#
-# First define the accessory in the `accessories`
-accessories:
-  mysql:
-
-    # Service name
-    #
-    # This is used in the service label and defaults to `<service>-<accessory>`
-    # where `<service>` is the main service name from the root configuration
-    service: mysql
-
-    # Image
-    #
-    # The Docker image to use, prefix with a registry if not using Docker hub
-    image: mysql:8.0
-
-    # Accessory hosts
-    #
-    # Specify one  of `host`, `hosts` or `roles`
-    host: mysql-db1
-    hosts:
-      - mysql-db1
-      - mysql-db2
-    roles:
-      - mysql
-
-    # Custom command
-    #
-    # You can set a custom command to run in the container, if you do not want to use the default
-    cmd: "bin/mysqld"
-
-    # Port mappings
-    #
-    # See https://docs.docker.com/network/, especially note the warning about the security
-    # implications of exposing ports publicly.
-    port: "127.0.0.1:3306:3306"
-
-    # Labels
-    labels:
-      app: myapp
-
-    # Options
-    # These are passed to the Docker run command in the form `--<name> <value>`
-    options:
-      restart: always
-      cpus: 2
-
-    # Environment variables
-    # See kamal docs env for more information
-    env:
-      ...
-
-    # Copying files
-    #
-    # You can specify files to mount into the container.
-    # The format is `local:remote` where `local` is the path to the file on the local machine
-    # and `remote` is the path to the file in the container.
-    #
-    # They will be uploaded from the local repo to the host and then mounted.
-    #
-    # ERB files will be evaluated before being copied.
-    files:
-      - config/my.cnf.erb:/etc/mysql/my.cnf
-      - config/myoptions.cnf:/etc/mysql/myoptions.cnf
-
-    # Directories
-    #
-    # You can specify directories to mount into the container. They will be created on the host
-    # before being mounted
-    directories:
-      - mysql-logs:/var/log/mysql
-
-    # Volumes
-    #
-    # Any other volumes to mount, in addition to the files and directories.
-    # They are not created or copied before mounting
-    volumes:
-      - /path/to/mysql-logs:/var/log/mysql
--- a/lib/kamal/configuration/docs/boot.yml
+++ b/lib/kamal/configuration/docs/boot.yml
@@ -1,19 +0,0 @@
-# Booting
-#
-# When deploying to large numbers of hosts, you might prefer not to restart your services on every host at the same time.
-#
-# Kamal’s default is to boot new containers on all hosts in parallel. But you can control this with the boot configuration.
-
-# Fixed group sizes
-#
-# Here we boot 2 hosts at a time with a 10 second gap between each group.
-boot:
-  limit: 2
-  wait: 10
-
-# Percentage of hosts
-#
-# Here we boot 25% of the hosts at a time with a 2 second gap between each group.
-boot:
-  limit: 25%
-  wait: 2
--- a/lib/kamal/configuration/docs/builder.yml
+++ b/lib/kamal/configuration/docs/builder.yml
@@ -1,107 +0,0 @@
-# Builder
-#
-# The builder configuration controls how the application is built with `docker build` or `docker buildx build`
-#
-# If no configuration is specified, Kamal will:
-# 1. Create a buildx context called `kamal-<service>-multiarch`
-# 2. Use `docker buildx build` to build a multiarch image for linux/amd64,linux/arm64 with that context
-#
-# See https://kamal-deploy.org/docs/configuration/builder-examples/ for more information
-
-# Builder options
-#
-# Options go under the builder key in the root configuration.
-builder:
-
-  # Multiarch
-  #
-  # Enables multiarch builds, defaults to `true`
-  multiarch: false
-
-  # Local configuration
-  #
-  # The build configuration for local builds, only used if multiarch is enabled (the default)
-  #
-  # If there is no remote configuration, by default we build for amd64 and arm64.
-  # If you only want to build for one architecture, you can specify it here.
-  # The docker socket is optional and uses the default docker host socket when not specified
-  local:
-    arch: amd64
-    host: /var/run/docker.sock
-
-  # Remote configuration
-  #
-  # The build configuration for remote builds, also only used if multiarch is enabled.
-  # The arch is required and can be either amd64 or arm64.
-  remote:
-    arch: arm64
-    host: ssh://docker@docker-builder
-
-  # Builder cache
-  #
-  # The type must be either 'gha' or 'registry'
-  #
-  # The image is only used for registry cache
-  cache:
-    type: registry
-    options: mode=max
-    image: kamal-app-build-cache
-
-  # Build context
-  #
-  # If this is not set, then a local git clone of the repo is used.
-  # This ensures a clean build with no uncommitted changes.
-  #
-  # To use the local checkout instead you can set the context to `.`, or a path to another directory.
-  context: .
-
-  # Dockerfile
-  #
-  # The Dockerfile to use for building, defaults to `Dockerfile`
-  dockerfile: Dockerfile.production
-
-  # Build target
-  #
-  # If not set, then the default target is used
-  target: production
-
-  # Build Arguments
-  #
-  # Any additional build arguments, passed to `docker build` with `--build-arg <key>=<value>`
-  args:
-    ENVIRONMENT: production
-
-  # Referencing build arguments
-  #
-  # ```shell
-  # ARG RUBY_VERSION
-  # FROM ruby:$RUBY_VERSION-slim as base
-  # ```
-
-  # Build secrets
-  #
-  # Values are read from the environment.
-  #
-  secrets:
-    - SECRET1
-    - SECRET2
-
-  # Referencing Build Secrets
-  #
-  # ```shell
-  # # Copy Gemfiles
-  # COPY Gemfile Gemfile.lock ./
-  #
-  # # Install dependencies, including private repositories via access token
-  # # Then remove bundle cache with exposed GITHUB_TOKEN)
-  # RUN --mount=type=secret,id=GITHUB_TOKEN \
-  #   BUNDLE_GITHUB__COM=x-access-token:$(cat /run/secrets/GITHUB_TOKEN) \
-  #   bundle install && \
-  #   rm -rf /usr/local/bundle/cache
-  # ```
-
-
-  # SSH
-  #
-  # SSH agent socket or keys to expose to the build
-  ssh: default=$SSH_AUTH_SOCK
--- a/lib/kamal/configuration/docs/configuration.yml
+++ b/lib/kamal/configuration/docs/configuration.yml
@@ -1,168 +0,0 @@
-# Kamal Configuration
-#
-# Configuration is read from the `config/deploy.yml`
-#
-
-# Destinations
-#
-# When running commands, you can specify a destination with the `-d` flag,
-# e.g. `kamal deploy -d staging`
-#
-# In this case the configuration will also be read from `config/deploy.staging.yml`
-# and merged with the base configuration.
-
-# Extensions
-#
-# Kamal will not accept unrecognized keys in the configuration file.
-#
-# However, you might want to declare a configuration block using YAML anchors
-# and aliases to avoid repetition.
-#
-# You can use prefix a configuration section with `x-` to indicate that it is an
-# extension. Kamal will ignore the extension and not raise an error.
-
-# The service name
-# This is a required value. It is used as the container name prefix.
-service: myapp
-
-# The Docker image name
-#
-# The image will be pushed to the configured registry.
-image: my-image
-
-# Labels
-#
-# Additional labels to add to the container
-labels:
-  my-label: my-value
-
-# Additional volumes to mount into the container
-volumes:
-  - /path/on/host:/path/in/container:ro
-
-# Registry
-#
-# The Docker registry configuration, see kamal docs registry
-registry:
-  ...
-
-# Servers
-#
-# The servers to deploy to, optionally with custom roles, see kamal docs servers
-servers:
-  ...
-
-# Environment variables
-#
-# See kamal docs env
-env:
-  ...
-
-# Asset Bridging
-#
-# Used for asset bridging across deployments, default to `nil`
-#
-# If there are changes to CSS or JS files, we may get requests
-# for the old versions on the new container and vice-versa.
-#
-# To avoid 404s we can specify an asset path.
-# Kamal will replace that path in the container with a mapped
-# volume containing both sets of files.
-# This requires that file names change when the contents change
-# (e.g. by including a hash of the contents in the name).
-
-# To configure this, set the path to the assets:
-asset_path: /path/to/assets
-
-# Path to hooks, defaults to `.kamal/hooks`
-# See https://kamal-deploy.org/docs/hooks for more information
-hooks_path: /user_home/kamal/hooks
-
-# Require destinations
-#
-# Whether deployments require a destination to be specified, defaults to `false`
-require_destination: true
-
-# The primary role
-#
-# This defaults to `web`, but if you have no web role, you can change this
-primary_role: workers
-
-# Allowing empty roles
-#
-# Whether roles with no servers are allowed. Defaults to `false`.
-allow_empty_roles: false
-
-# Stop wait time
-#
-# How long we wait for a container to stop before killing it, defaults to 30 seconds
-stop_wait_time: 60
-
-# Retain containers
-#
-# How many old containers and images we retain, defaults to 5
-retain_containers: 3
-
-# Minimum version
-#
-# The minimum version of Kamal required to deploy this configuration, defaults to nil
-minimum_version: 1.3.0
-
-# Readiness delay
-#
-# Seconds to wait for a container to boot after is running, default 7
-# This only applies to containers that do not specify a healthcheck
-readiness_delay: 4
-
-# Run directory
-#
-# Directory to store kamal runtime files in on the host, default `.kamal`
-run_directory: /etc/kamal
-
-# SSH options
-#
-# See kamal docs ssh
-ssh:
-  ...
-
-# Builder options
-#
-# See kamal docs builder
-builder:
-  ...
-
-# Accessories
-#
-# Additionals services to run in Docker, see kamal docs accessory
-accessories:
-  ...
-
-# Traefik
-#
-# The Traefik proxy is used for zero-downtime deployments, see kamal docs traefik
-traefik:
-  ...
-
-# SSHKit
-#
-# See kamal docs sshkit
-sshkit:
-  ...
-
-# Boot options
-#
-# See kamal docs boot
-boot:
-  ...
-
-# Healthcheck
-#
-# Configuring healthcheck commands, intervals and timeouts, see kamal docs healthcheck
-healthcheck:
-  ...
-
-# Logging
-#
-# Docker logging configuration, see kamal docs logging
-logging:
-  ...
--- a/lib/kamal/configuration/docs/env.yml
+++ b/lib/kamal/configuration/docs/env.yml
@@ -1,72 +0,0 @@
-# Environment variables
-#
-# Environment variables can be set directory in the Kamal configuration or
-# for loaded from a .env file, for secrets that should not be checked into Git.
-
-# Reading environment variables from the configuration
-#
-# Environment variables can be set directly in the configuration file.
-#
-# These are passed to the docker run command when deploying.
-env:
-  DATABASE_HOST: mysql-db1
-  DATABASE_PORT: 3306
-
-# Using .env file to load required environment variables
-#
-# Kamal uses dotenv to automatically load environment variables set in the .env file present
-# in the application root.
-#
-# This file can be used to set variables like KAMAL_REGISTRY_PASSWORD or database passwords.
-# But for this reason you must ensure that .env files are not checked into Git or included
-# in your Dockerfile! The format is just key-value like:
-# ```
-# KAMAL_REGISTRY_PASSWORD=pw
-# DB_PASSWORD=secret123
-# ```
-# See https://kamal-deploy.org/docs/commands/envify/ for how to use generated .env files.
-#
-# To pass the secrets you should list them under the `secret` key. When you do this the
-# other variables need to be moved under the `clear` key.
-#
-# Unlike clear values, secrets are not passed directly to the container,
-# but are stored in an env file on the host
-# The file is not updated when deploying, only when running `kamal envify` or `kamal env push`.
-env:
-  clear:
-    DB_USER: app
-  secret:
-    - DB_PASSWORD
-
-# Tags
-#
-# Tags are used to add extra env variables to specific hosts.
-# See kamal docs servers for how to tag hosts.
-#
-# Tags are only allowed in the top level env configuration (i.e not under a role specific env).
-#
-# The env variables can be specified with secret and clear values as explained above.
-env:
-  tags:
-    <tag1>:
-      MYSQL_USER: monitoring
-    <tag2>:
-      clear:
-        MYSQL_USER: readonly
-      secret:
-        - MYSQL_PASSWORD
-
-# Example configuration
-env:
-  clear:
-    MYSQL_USER: app
-  secret:
-    - MYSQL_PASSWORD
-  tags:
-    monitoring:
-      MYSQL_USER: monitoring
-    replica:
-      clear:
-        MYSQL_USER: readonly
-      secret:
-        - READONLY_PASSWORD
--- a/lib/kamal/configuration/docs/healthcheck.yml
+++ b/lib/kamal/configuration/docs/healthcheck.yml
@@ -1,59 +0,0 @@
-# Healthcheck configuration
-#
-# On roles that are running Traefik, Kamal will supply a default healthcheck to `docker run`.
-# For other roles, by default no healthcheck is supplied.
-#
-# If no healthcheck is supplied and the image does not define one, they we wait for the container
-# to reach a running state and then pause for the readiness delay.
-#
-# The default healthcheck is `curl -f http://localhost:<port>/<path>`, so it assumes that `curl`
-# is available within the container.
-
-# Healthcheck options
-#
-# These go under the `healthcheck` key in the root or role configuration.
-healthcheck:
-
-  # Command
-  #
-  # The command to run, defaults to `curl -f http://localhost:<port>/<path>` on roles running Traefik
-  cmd: "curl -f http://localhost"
-
-  # Interval
-  #
-  # The Docker healthcheck interval, defaults to `1s`
-  interval: 10s
-
-  # Max attempts
-  #
-  # The maximum number of times we poll the container to see if it is healthy, defaults to `7`
-  # Each check is separated by an increasing interval starting with 1 second.
-  max_attempts: 3
-
-  # Port
-  #
-  # The port to use in the healthcheck, defaults to `3000`
-  port: "80"
-
-  # Path
-  #
-  # The path to use in the healthcheck, defaults to `/up`
-  path: /health
-
-  # Cords for zero-downtime deployments
-  #
-  # The cord file is used for zero-downtime deployments. The healthcheck is augmented with a check
-  # for the existance of the file. This allows us to delete the file and force the container to
-  # become unhealthy, causing Traefik to stop routing traffic to it.
-  #
-  # Kamal mounts a volume at this location and creates the file before starting the container.
-  # You can set the value to `false` to disable the cord file, but this loses the zero-downtime
-  # guarantee.
-  #
-  # The default value is `/tmp/kamal-cord`
-  cord: /cord
-
-  # Log lines
-  #
-  # Number of lines to log from the container when the healthcheck fails, defaults to `50`
-  log_lines: 100
--- a/lib/kamal/configuration/docs/logging.yml
+++ b/lib/kamal/configuration/docs/logging.yml
@@ -1,21 +0,0 @@
-# Custom logging configuration
-#
-# Set these to control the Docker logging driver and options.
-
-# Logging settings
-#
-# These go under the logging key in the configuration file.
-#
-# This can be specified in the root level or for a specific role.
-logging:
-
-  # Driver
-  #
-  # The logging driver to use, passed to Docker via `--log-driver`
-  driver: json-file
-
-  # Options
-  #
-  # Any logging options to pass to the driver, passed to Docker via `--log-opt`
-  options:
-    max-size: 100m
--- a/lib/kamal/configuration/docs/registry.yml
+++ b/lib/kamal/configuration/docs/registry.yml
@@ -1,49 +0,0 @@
-# Registry
-#
-# The default registry is Docker Hub, but you can change it using registry/server:
-#
-# A reference to secret (in this case DOCKER_REGISTRY_TOKEN) will look up the secret
-# in the local environment.
-
-registry:
-  server: registry.digitalocean.com
-  username:
-    - DOCKER_REGISTRY_TOKEN
-  password:
-    - DOCKER_REGISTRY_TOKEN
-
-# Using AWS ECR as the container registry
-# You will need to have the aws CLI installed locally for this to work.
-# AWS ECR’s access token is only valid for 12hrs. In order to not have to manually regenerate the token every time, you can use ERB in the deploy.yml file to shell out to the aws cli command, and obtain the token:
-
-registry:
-  server: <your aws account id>.dkr.ecr.<your aws region id>.amazonaws.com
-  username: AWS
-  password: <%= %x(aws ecr get-login-password) %>
-
-# Using GCP Artifact Registry as the container registry
-# To sign into Artifact Registry, you would need to
-# [create a service account](https://cloud.google.com/iam/docs/service-accounts-create#creating)
-# and [set up roles and permissions](https://cloud.google.com/artifact-registry/docs/access-control#permissions).
-# Normally, assigning a roles/artifactregistry.writer role should be sufficient.
-#
-# Once the service account is ready, you need to generate and download a JSON key, base64 encode it and add to .env:
-#
-# ```shell
-# echo "KAMAL_REGISTRY_PASSWORD=$(base64 -i /path/to/key.json)" | tr -d "\\n"  >> .env
-# ```
-# Use the env variable as password along with _json_key_base64 as username.
-# Here’s the final configuration:
-
-registry:
-  server: <your registry region>-docker.pkg.dev
-  username: _json_key_base64
-  password:
-    - KAMAL_REGISTRY_PASSWORD
-
-# Validating the configuration
-#
-# You can validate the configuration by running:
-# ```shell
-# kamal registry login
-# ```
--- a/lib/kamal/configuration/docs/role.yml
+++ b/lib/kamal/configuration/docs/role.yml
@@ -1,52 +0,0 @@
-# Roles
-#
-# Roles are used to configure different types of servers in the deployment.
-# The most common use for this is to run a web servers and job servers.
-#
-# Kamal expects there to be a `web` role, unless you set a different `primary_role`
-# in the root configuration.
-
-# Role configuration
-#
-# Roles are specified under the servers key
-servers:
-
-  # Simple role configuration
-  #
-  #
-  # This can be a list of hosts, if you don't need custom configuration for the role.
-  #
-  # You can set tags on the hosts for custom env variables (see kamal docs env)
-  web:
-    - 172.1.0.1
-    - 172.1.0.2: experiment1
-    - 172.1.0.2: [ experiment1, experiment2 ]
-
-  # Custom role configuration
-  #
-  # When there are other options to set, the list of hosts goes under the `hosts` key
-  #
-  # By default only the primary role uses Traefik, but you can set `traefik` to change
-  # it.
-  #
-  # You can also set a custom cmd to run in the container, and overwrite other settings
-  # from the root configuration.
-  workers:
-    hosts:
-      - 172.1.0.3
-      - 172.1.0.4: experiment1
-    traefik: true
-    cmd: "bin/jobs"
-    options:
-      memory: 2g
-      cpus: 4
-    healthcheck:
-      ...
-    logging:
-      ...
-    labels:
-      my-label: workers
-    env:
-      ...
-    asset_path: /public
-
--- a/lib/kamal/configuration/docs/servers.yml
+++ b/lib/kamal/configuration/docs/servers.yml
@@ -1,27 +0,0 @@
-# Servers
-#
-# Servers are split into different roles, with each role having its own configuration.
-#
-# For simpler deployments though where all servers are identical, you can just specify a list of servers
-# They will be implicitly assigned to the `web` role.
-servers:
-  - 172.0.0.1
-  - 172.0.0.2
-  - 172.0.0.3
-
-# Tagging servers
-#
-# Servers can be tagged, with the tags used to add custom env variables (see kamal docs env).
-servers:
-  - 172.0.0.1
-  - 172.0.0.2: experiments
-  - 172.0.0.3: [ experiments, three ]
-
-# Roles
-#
-# For more complex deployments (e.g. if you are running job hosts), you can specify roles, and configure each separately (see kamal docs role)
-servers:
-  web:
-    ...
-  workers:
-    ...
--- a/lib/kamal/configuration/docs/ssh.yml
+++ b/lib/kamal/configuration/docs/ssh.yml
@@ -1,66 +0,0 @@
-# SSH configuration
-#
-# Kamal uses SSH to connect run commands on your hosts.
-# By default it will attempt to connect to the root user on port 22
-#
-# If you are using non-root user, you may need to bootstrap your servers manually, before using them with Kamal. On Ubuntu, you’d do:
-#
-# ```shell
-# sudo apt update
-# sudo apt upgrade -y
-# sudo apt install -y docker.io curl git
-# sudo usermod -a -G docker app
-# ```
-
-
-# SSH options
-#
-# The options are specified under the ssh key in the configuration file.
-ssh:
-
-  # The SSH user
-  #
-  # Defaults to `root`
-  #
-  user: app
-
-  # The SSH port
-  #
-  # Defaults to 22
-  port: "2222"
-
-  # Proxy host
-  #
-  # Specified in the form <host> or <user>@<host>
-  proxy: root@proxy-host
-
-  # Proxy command
-  #
-  # A custom proxy command, required for older versions of SSH
-  proxy_command: "ssh -W %h:%p user@proxy"
-
-  # Log level
-  #
-  # Defaults to `fatal`. Set this to debug if you are having
-  # SSH connection issues.
-  log_level: debug
-
-  # Keys Only
-  #
-  # Set to true to use only private keys from keys and key_data parameters, 
-  # even if ssh-agent offers more identities. This option is intended for 
-  # situations where ssh-agent offers many different identites or you have 
-  # a need to overwrite all identites and force a single one.
-  keys_only: false
-
-  # Keys
-  #
-  # An array of file names of private keys to use for publickey
-  # and hostbased authentication
-  keys: [ "~/.ssh/id.pem" ]
-
-  # Key Data
-  #
-  # An array of strings, with each element of the array being
-  # a raw private key in PEM format.
-  key_data: [ "-----BEGIN OPENSSH PRIVATE KEY-----" ]
--- a/lib/kamal/configuration/docs/sshkit.yml
+++ b/lib/kamal/configuration/docs/sshkit.yml
@@ -1,23 +0,0 @@
-# SSHKit
-#
-# [SSHKit](https://github.com/capistrano/sshkit) is the SSH toolkit used by Kamal.
-#
-# The default settings should be sufficient for most use cases, but
-# when connecting to a large number of hosts you may need to adjust
-
-# SSHKit options
-#
-# The options are specified under the sshkit key in the configuration file.
-sshkit:
-
-  # Max concurrent starts
-  #
-  # Creating SSH connections concurrently can be an issue when deploying to many servers.
-  # By default Kamal will limit concurrent connection starts to 30 at a time.
-  max_concurrent_starts: 10
-
-  # Pool idle timeout
-  #
-  # Kamal sets a long idle timeout of 900 seconds on connections to try to avoid
-  # re-connection storms after an idle period, like building an image or waiting for CI.
-  pool_idle_timeout: 300
--- a/lib/kamal/configuration/docs/traefik.yml
+++ b/lib/kamal/configuration/docs/traefik.yml
@@ -1,62 +0,0 @@
-# Traefik
-#
-# Traefik is a reverse proxy, used by Kamal for zero-downtime deployments.
-#
-# We start an instance on the hosts in it's own container.
-#
-# During a deployment:
-# 1. We start a new container which Traefik automatically detects due to the labels we have applied
-# 2. Traefik starts routing traffic to the new container
-# 3. We force the old container to fail it's healthcheck, causing Traefik to stop routing traffic to it
-# 4. We stop the old container
-
-# Traefik settings
-#
-# Traekik is configured in the root configuration under `traefik`.
-traefik:
-
-  # Image
-  #
-  # The Traefik image to use, defaults to `traefik:v2.10`
-  image: traefik:v2.9
-
-  # Host port
-  #
-  # The host port to publish the Traefik container on, defaults to `80`
-  host_port: "8080"
-
-  # Disabling publishing
-  #
-  # To avoid publishing the Traefik container, set this to `false`
-  publish: false
-
-  # Labels
-  #
-  # Additional labels to apply to the Traefik container
-  labels:
-    traefik.http.routers.catchall.entryPoints: http
-    traefik.http.routers.catchall.rule: PathPrefix(`/`)
-    traefik.http.routers.catchall.service: unavailable
-    traefik.http.routers.catchall.priority: "1"
-    traefik.http.services.unavailable.loadbalancer.server.port: "0"
-
-  # Arguments
-  #
-  # Additional arguments to pass to the Traefik container
-  args:
-    entryPoints.http.address: ":80"
-    entryPoints.http.forwardedHeaders.insecure: true
-    accesslog: true
-    accesslog.format: json
-
-  # Options
-  #
-  # Additional options to pass to `docker run`
-  options:
-    cpus: 2
-
-  # Environment variables
-  #
-  # See kamal docs env
-  env:
-    ...
--- a/lib/kamal/configuration/env.rb
+++ b/lib/kamal/configuration/env.rb
@@ -1,15 +1,18 @@
 class Kamal::Configuration::Env
-  include Kamal::Configuration::Validation
-
-  attr_reader :secrets_keys, :clear, :secrets_file, :context
+  attr_reader :secrets_keys, :clear, :secrets_file
  delegate :argumentize, to: Kamal::Utils

-  def initialize(config:, secrets_file: nil, context: "env")
-    @clear = config.fetch("clear", config.key?("secret") || config.key?("tags") ? {} : config)
-    @secrets_keys = config.fetch("secret", [])
+  def self.from_config(config:, secrets_file: nil)
+    secrets_keys = config.fetch("secret", [])
+    clear = config.fetch("clear", config.key?("secret") ? {} : config)
+
+    new clear: clear, secrets_keys: secrets_keys, secrets_file: secrets_file
+  end
+
+  def initialize(clear:, secrets_keys:, secrets_file:)
+    @clear = clear
+    @secrets_keys = secrets_keys
    @secrets_file = secrets_file
-    @context = context
-    validate! config, context: context, with: Kamal::Configuration::Validator::Env
  end

  def args
@@ -30,7 +33,8 @@ class Kamal::Configuration::Env

  def merge(other)
    self.class.new \
-      config: { "clear" => clear.merge(other.clear), "secret" => secrets_keys | other.secrets_keys },
-      secrets_file: secrets_file || other.secrets_file
+      clear: @clear.merge(other.clear),
+      secrets_keys: @secrets_keys | other.secrets_keys,
+      secrets_file: secrets_file
  end
 end
--- a/lib/kamal/configuration/env/tag.rb
+++ b/lib/kamal/configuration/env/tag.rb
@@ -1,12 +0,0 @@
-class Kamal::Configuration::Env::Tag
-  attr_reader :name, :config
-
-  def initialize(name, config:)
-    @name = name
-    @config = config
-  end
-
-  def env
-    Kamal::Configuration::Env.new(config: config)
-  end
-end
--- a/lib/kamal/configuration/healthcheck.rb
+++ b/lib/kamal/configuration/healthcheck.rb
@@ -1,63 +0,0 @@
-class Kamal::Configuration::Healthcheck
-  include Kamal::Configuration::Validation
-
-  attr_reader :healthcheck_config
-
-  def initialize(healthcheck_config:, context: "healthcheck")
-    @healthcheck_config = healthcheck_config || {}
-    validate! @healthcheck_config, context: context
-  end
-
-  def merge(other)
-    self.class.new healthcheck_config: healthcheck_config.deep_merge(other.healthcheck_config)
-  end
-
-  def cmd
-    healthcheck_config.fetch("cmd", http_health_check)
-  end
-
-  def port
-    healthcheck_config.fetch("port", 3000)
-  end
-
-  def path
-    healthcheck_config.fetch("path", "/up")
-  end
-
-  def max_attempts
-    healthcheck_config.fetch("max_attempts", 7)
-  end
-
-  def interval
-    healthcheck_config.fetch("interval", "1s")
-  end
-
-  def cord
-    healthcheck_config.fetch("cord", "/tmp/kamal-cord")
-  end
-
-  def log_lines
-    healthcheck_config.fetch("log_lines", 50)
-  end
-
-  def set_port_or_path?
-    healthcheck_config["port"].present? || healthcheck_config["path"].present?
-  end
-
-  def to_h
-    {
-      "cmd" => cmd,
-      "interval" => interval,
-      "max_attempts" => max_attempts,
-      "port" => port,
-      "path" => path,
-      "cord" => cord,
-      "log_lines" => log_lines
-    }
-  end
-
-  private
-    def http_health_check
-      "curl -f #{URI.join("http://localhost:#{port}", path)} || exit 1" if path.present? || port.present?
-    end
-end
--- a/lib/kamal/configuration/logging.rb
+++ b/lib/kamal/configuration/logging.rb
@@ -1,33 +0,0 @@
-class Kamal::Configuration::Logging
-  delegate :optionize, :argumentize, to: Kamal::Utils
-
-  include Kamal::Configuration::Validation
-
-  attr_reader :logging_config
-
-  def initialize(logging_config:, context: "logging")
-    @logging_config = logging_config || {}
-    validate! @logging_config, context: context
-  end
-
-  def driver
-    logging_config["driver"]
-  end
-
-  def options
-    logging_config.fetch("options", {})
-  end
-
-  def merge(other)
-    self.class.new logging_config: logging_config.deep_merge(other.logging_config)
-  end
-
-  def args
-    if driver.present? || options.present?
-      optionize({ "log-driver" => driver }.compact) +
-        argumentize("--log-opt", options)
-    else
-      argumentize("--log-opt", { "max-size" => "10m" })
-    end
-  end
-end
--- a/lib/kamal/configuration/registry.rb
+++ b/lib/kamal/configuration/registry.rb
@@ -1,31 +0,0 @@
-class Kamal::Configuration::Registry
-  include Kamal::Configuration::Validation
-
-  attr_reader :registry_config
-
-  def initialize(config:)
-    @registry_config = config.raw_config.registry || {}
-    validate! registry_config, with: Kamal::Configuration::Validator::Registry
-  end
-
-  def server
-    registry_config["server"]
-  end
-
-  def username
-    lookup("username")
-  end
-
-  def password
-    lookup("password")
-  end
-
-  private
-    def lookup(key)
-      if registry_config[key].is_a?(Array)
-        ENV.fetch(registry_config[key].first).dup
-      else
-        registry_config[key]
-      end
-    end
-end
--- a/lib/kamal/configuration/role.rb
+++ b/lib/kamal/configuration/role.rb
@@ -1,33 +1,12 @@
 class Kamal::Configuration::Role
-  include Kamal::Configuration::Validation
-
  CORD_FILE = "cord"
  delegate :argumentize, :optionize, to: Kamal::Utils

-  attr_reader :name, :config, :specialized_env, :specialized_logging, :specialized_healthcheck
-
+  attr_accessor :name
  alias to_s name

  def initialize(name, config:)
    @name, @config = name.inquiry, config
-    validate! \
-      specializations,
-      example: validation_yml["servers"]["workers"],
-      context: "servers/#{name}",
-      with: Kamal::Configuration::Validator::Role
-
-    @specialized_env = Kamal::Configuration::Env.new \
-      config: specializations.fetch("env", {}),
-      secrets_file: File.join(config.host_env_directory, "roles", "#{container_prefix}.env"),
-      context: "servers/#{name}/env"
-
-    @specialized_logging = Kamal::Configuration::Logging.new \
-      logging_config: specializations.fetch("logging", {}),
-      context: "servers/#{name}/logging"
-
-    @specialized_healthcheck = Kamal::Configuration::Healthcheck.new \
-      healthcheck_config: specializations.fetch("healthcheck", {}),
-      context: "servers/#{name}/healthcheck"
  end

  def primary_host
@@ -35,11 +14,7 @@ class Kamal::Configuration::Role
  end

  def hosts
-    tagged_hosts.keys
-  end
-
-  def env_tags(host)
-    tagged_hosts.fetch(host).collect { |tag| config.env_tag(tag) }
+    @hosts ||= extract_hosts_from_config
  end

  def cmd
@@ -63,21 +38,24 @@ class Kamal::Configuration::Role
  end

  def logging_args
-    logging.args
-  end
+    args = config.logging || {}
+    args.deep_merge!(specializations["logging"]) if specializations["logging"].present?

-  def logging
-    @logging ||= config.logging.merge(specialized_logging)
+    if args.any?
+      optionize({ "log-driver" => args["driver"] }.compact) +
+        argumentize("--log-opt", args["options"])
+    else
+      config.logging_args
+    end
  end


-  def env(host)
-    @envs ||= {}
-    @envs[host] ||= [ config.env, specialized_env, *env_tags(host).map(&:env) ].reduce(:merge)
+  def env
+    @env ||= base_env.merge(specialized_env)
  end

-  def env_args(host)
-    env(host).args
+  def env_args
+    env.args
  end

  def asset_volume_args
@@ -86,29 +64,28 @@ class Kamal::Configuration::Role


  def health_check_args(cord: true)
-    if running_traefik? || healthcheck.set_port_or_path?
+    if health_check_cmd.present?
      if cord && uses_cord?
-        optionize({ "health-cmd" => health_check_cmd_with_cord, "health-interval" => healthcheck.interval })
+        optionize({ "health-cmd" => health_check_cmd_with_cord, "health-interval" => health_check_interval })
          .concat(cord_volume.docker_args)
      else
-        optionize({ "health-cmd" => healthcheck.cmd, "health-interval" => healthcheck.interval })
+        optionize({ "health-cmd" => health_check_cmd, "health-interval" => health_check_interval })
      end
    else
      []
    end
  end

-  def healthcheck
-    @healthcheck ||=
-      if running_traefik?
-        config.healthcheck.merge(specialized_healthcheck)
-      else
-        specialized_healthcheck
-      end
+  def health_check_cmd
+    health_check_options["cmd"] || http_health_check(port: health_check_options["port"], path: health_check_options["path"])
  end

  def health_check_cmd_with_cord
-    "(#{healthcheck.cmd}) && (stat #{cord_container_file} > /dev/null || exit 1)"
+    "(#{health_check_cmd}) && (stat #{cord_container_file} > /dev/null || exit 1)"
+  end
+
+  def health_check_interval
+    health_check_options["interval"] || "1s"
  end


@@ -126,7 +103,7 @@ class Kamal::Configuration::Role


  def uses_cord?
-    running_traefik? && cord_volume && healthcheck.cmd.present?
+    running_traefik? && cord_volume && health_check_cmd.present?
  end

  def cord_host_directory
@@ -134,7 +111,7 @@ class Kamal::Configuration::Role
  end

  def cord_volume
-    if (cord = healthcheck.cord)
+    if (cord = health_check_options["cord"])
      @cord_volume ||= Kamal::Configuration::Volume.new \
        host_path: File.join(config.run_directory, "cords", [ container_prefix, config.run_id ].join("-")),
        container_path: cord
@@ -187,37 +164,22 @@ class Kamal::Configuration::Role
  end

  private
-    def tagged_hosts
-      {}.tap do |tagged_hosts|
-        extract_hosts_from_config.map do |host_config|
-          if host_config.is_a?(Hash)
-            host, tags = host_config.first
-            tagged_hosts[host] = Array(tags)
-          elsif host_config.is_a?(String)
-            tagged_hosts[host_config] = []
-          end
-        end
-      end
-    end
+    attr_accessor :config

    def extract_hosts_from_config
-      if config.raw_config.servers.is_a?(Array)
-        config.raw_config.servers
+      if config.servers.is_a?(Array)
+        config.servers
      else
-        servers = config.raw_config.servers[name]
+        servers = config.servers[name]
        servers.is_a?(Array) ? servers : Array(servers["hosts"])
      end
    end

    def default_labels
-      { "service" => config.service, "role" => name, "destination" => config.destination }
-    end
-
-    def specializations
-      if config.raw_config.servers.is_a?(Array) || config.raw_config.servers[name].is_a?(Array)
-        {}
+      if config.destination
+        { "service" => config.service, "role" => name, "destination" => config.destination }
      else
-        config.raw_config.servers[name]
+        { "service" => config.service, "role" => name }
      end
    end

@@ -248,4 +210,35 @@ class Kamal::Configuration::Role
        labels.merge!(specializations["labels"]) if specializations["labels"].present?
      end
    end
+
+    def specializations
+      if config.servers.is_a?(Array) || config.servers[name].is_a?(Array)
+        {}
+      else
+        config.servers[name].except("hosts")
+      end
+    end
+
+    def specialized_env
+      Kamal::Configuration::Env.from_config config: specializations.fetch("env", {})
+    end
+
+    # Secrets are stored in an array, which won't merge by default, so have to do it by hand.
+    def base_env
+      Kamal::Configuration::Env.from_config \
+        config: config.env,
+        secrets_file: File.join(config.host_env_directory, "roles", "#{container_prefix}.env")
+    end
+
+    def http_health_check(port:, path:)
+      "curl -f #{URI.join("http://localhost:#{port}", path)} || exit 1" if path.present? || port.present?
+    end
+
+    def health_check_options
+      @health_check_options ||= begin
+        options = specializations["healthcheck"] || {}
+        options = config.healthcheck.merge(options) if running_traefik?
+        options
+      end
+    end
 end
--- a/lib/kamal/configuration/servers.rb
+++ b/lib/kamal/configuration/servers.rb
@@ -1,18 +0,0 @@
-class Kamal::Configuration::Servers
-  include Kamal::Configuration::Validation
-
-  attr_reader :config, :servers_config, :roles
-
-  def initialize(config:)
-    @config = config
-    @servers_config = config.raw_config.servers
-    validate! servers_config, with: Kamal::Configuration::Validator::Servers
-
-    @roles = role_names.map { |role_name| Kamal::Configuration::Role.new role_name, config: config }
-  end
-
-  private
-    def role_names
-      servers_config.is_a?(Array) ? [ "web" ] : servers_config.keys.sort
-    end
-end
--- a/lib/kamal/configuration/ssh.rb
+++ b/lib/kamal/configuration/ssh.rb
@@ -1,45 +1,28 @@
 class Kamal::Configuration::Ssh
  LOGGER = ::Logger.new(STDERR)

-  include Kamal::Configuration::Validation
-
-  attr_reader :ssh_config
-
  def initialize(config:)
-    @ssh_config = config.raw_config.ssh || {}
-    validate! ssh_config
+    @config = config.raw_config.ssh || {}
  end

  def user
-    ssh_config.fetch("user", "root")
+    config.fetch("user", "root")
  end

  def port
-    ssh_config.fetch("port", 22)
+    config.fetch("port", 22)
  end

  def proxy
-    if (proxy = ssh_config["proxy"])
+    if (proxy = config["proxy"])
      Net::SSH::Proxy::Jump.new(proxy.include?("@") ? proxy : "root@#{proxy}")
-    elsif (proxy_command = ssh_config["proxy_command"])
+    elsif (proxy_command = config["proxy_command"])
      Net::SSH::Proxy::Command.new(proxy_command)
    end
  end

-  def keys_only
-    ssh_config["keys_only"]
-  end
-
-  def keys
-    ssh_config["keys"]
-  end
-
-  def key_data
-    ssh_config["key_data"]
-  end
-
  def options
-    { user: user, port: port, proxy: proxy, logger: logger, keepalive: true, keepalive_interval: 30, keys_only: keys_only, keys: keys, key_data: key_data }.compact
+    { user: user, port: port, proxy: proxy, logger: logger, keepalive: true, keepalive_interval: 30 }.compact
  end

  def to_h
@@ -47,11 +30,13 @@ class Kamal::Configuration::Ssh
  end

  private
+    attr_accessor :config
+
    def logger
      LOGGER.tap { |logger| logger.level = log_level }
    end

    def log_level
-      ssh_config.fetch("log_level", :fatal)
+      config.fetch("log_level", :fatal)
    end
 end
--- a/lib/kamal/configuration/sshkit.rb
+++ b/lib/kamal/configuration/sshkit.rb
@@ -1,22 +1,20 @@
 class Kamal::Configuration::Sshkit
-  include Kamal::Configuration::Validation
-
-  attr_reader :sshkit_config
-
  def initialize(config:)
-    @sshkit_config = config.raw_config.sshkit || {}
-    validate! sshkit_config
+    @options = config.raw_config.sshkit || {}
  end

  def max_concurrent_starts
-    sshkit_config.fetch("max_concurrent_starts", 30)
+    options.fetch("max_concurrent_starts", 30)
  end

  def pool_idle_timeout
-    sshkit_config.fetch("pool_idle_timeout", 900)
+    options.fetch("pool_idle_timeout", 900)
  end

  def to_h
-    sshkit_config
+    options
  end
+
+  private
+    attr_accessor :options
 end
--- a/lib/kamal/configuration/traefik.rb
+++ b/lib/kamal/configuration/traefik.rb
@@ -1,60 +0,0 @@
-class Kamal::Configuration::Traefik
-  DEFAULT_IMAGE = "traefik:v2.10"
-  CONTAINER_PORT = 80
-  DEFAULT_ARGS = {
-    "log.level" => "DEBUG"
-  }
-  DEFAULT_LABELS = {
-    # These ensure we serve a 502 rather than a 404 if no containers are available
-    "traefik.http.routers.catchall.entryPoints" => "http",
-    "traefik.http.routers.catchall.rule" => "PathPrefix(`/`)",
-    "traefik.http.routers.catchall.service" => "unavailable",
-    "traefik.http.routers.catchall.priority" => 1,
-    "traefik.http.services.unavailable.loadbalancer.server.port" => "0"
-  }
-
-  include Kamal::Configuration::Validation
-
-  attr_reader :config, :traefik_config
-
-  def initialize(config:)
-    @config = config
-    @traefik_config = config.raw_config.traefik || {}
-    validate! traefik_config
-  end
-
-  def publish?
-    traefik_config["publish"] != false
-  end
-
-  def labels
-    DEFAULT_LABELS.merge(traefik_config["labels"] || {})
-  end
-
-  def env
-    Kamal::Configuration::Env.new \
-      config: traefik_config.fetch("env", {}),
-      secrets_file: File.join(config.host_env_directory, "traefik", "traefik.env"),
-      context: "traefik/env"
-  end
-
-  def host_port
-    traefik_config.fetch("host_port", CONTAINER_PORT)
-  end
-
-  def options
-    traefik_config.fetch("options", {})
-  end
-
-  def port
-    "#{host_port}:#{CONTAINER_PORT}"
-  end
-
-  def args
-    DEFAULT_ARGS.merge(traefik_config.fetch("args", {}))
-  end
-
-  def image
-    traefik_config.fetch("image", DEFAULT_IMAGE)
-  end
-end
--- a/lib/kamal/configuration/validation.rb
+++ b/lib/kamal/configuration/validation.rb
@@ -1,27 +0,0 @@
-require "yaml"
-require "active_support/inflector"
-
-module Kamal::Configuration::Validation
-  extend ActiveSupport::Concern
-
-  class_methods do
-    def validation_doc
-      @validation_doc ||= File.read(File.join(File.dirname(__FILE__), "docs", "#{validation_config_key}.yml"))
-    end
-
-    def validation_config_key
-      @validation_config_key ||= name.demodulize.underscore
-    end
-  end
-
-  def validate!(config, example: nil, context: nil, with: Kamal::Configuration::Validator)
-    context ||= self.class.validation_config_key
-    example ||= validation_yml[self.class.validation_config_key]
-
-    with.new(config, example: example, context: context).validate!
-  end
-
-  def validation_yml
-    @validation_yml ||= YAML.load(self.class.validation_doc)
-  end
-end
--- a/lib/kamal/configuration/validator.rb
+++ b/lib/kamal/configuration/validator.rb
@@ -1,153 +0,0 @@
-class Kamal::Configuration::Validator
-  attr_reader :config, :example, :context
-
-  def initialize(config, example:, context:)
-    @config = config
-    @example = example
-    @context = context
-  end
-
-  def validate!
-    validate_against_example! config, example
-  end
-
-  private
-    def validate_against_example!(validation_config, example)
-      validate_type! validation_config, Hash
-
-      check_unknown_keys! validation_config, example
-
-      validation_config.each do |key, value|
-        next if extension?(key)
-        with_context(key) do
-          example_value = example[key]
-
-          if example_value == "..."
-            validate_type! value, *(Array if key == :servers), Hash
-          elsif key == "hosts"
-            validate_servers! value
-          elsif example_value.is_a?(Array)
-            validate_array_of! value, example_value.first.class
-          elsif example_value.is_a?(Hash)
-            case key.to_s
-            when "options", "args"
-              validate_type! value, Hash
-            when "labels"
-              validate_hash_of! value, example_value.first[1].class
-            else
-              validate_against_example! value, example_value
-            end
-          else
-            validate_type! value, example_value.class
-          end
-        end
-      end
-    end
-
-
-    def valid_type?(value, type)
-      value.is_a?(type) ||
-        (type == String && stringish?(value)) ||
-        (boolean?(type) && boolean?(value.class))
-    end
-
-    def type_description(type)
-      if type == Integer || type == Array
-        "an #{type.name.downcase}"
-      elsif type == TrueClass || type == FalseClass
-        "a boolean"
-      else
-        "a #{type.name.downcase}"
-      end
-    end
-
-    def boolean?(type)
-      type == TrueClass || type == FalseClass
-    end
-
-    def stringish?(value)
-      value.is_a?(String) || value.is_a?(Symbol) || value.is_a?(Numeric) || value.is_a?(TrueClass) || value.is_a?(FalseClass)
-    end
-
-    def validate_array_of!(array, type)
-      validate_type! array, Array
-
-      array.each_with_index do |value, index|
-        with_context(index) do
-          validate_type! value, type
-        end
-      end
-    end
-
-    def validate_hash_of!(hash, type)
-      validate_type! hash, Hash
-
-      hash.each do |key, value|
-        with_context(key) do
-          validate_type! value, type
-        end
-      end
-    end
-
-    def validate_servers!(servers)
-      validate_type! servers, Array
-
-      servers.each_with_index do |server, index|
-        with_context(index) do
-          validate_type! server, String, Hash
-
-          if server.is_a?(Hash)
-            error "multiple hosts found" unless server.size == 1
-            host, tags = server.first
-
-            with_context(host) do
-              validate_type! tags, String, Array
-              validate_array_of! tags, String if tags.is_a?(Array)
-            end
-          end
-        end
-      end
-    end
-
-    def validate_type!(value, *types)
-      type_error(*types) unless types.any? { |type| valid_type?(value, type) }
-    end
-
-    def error(message)
-      raise Kamal::ConfigurationError, "#{error_context}#{message}"
-    end
-
-    def type_error(*expected_types)
-      error "should be #{expected_types.map { |type| type_description(type) }.join(" or ")}"
-    end
-
-    def unknown_keys_error(unknown_keys)
-      error "unknown #{"key".pluralize(unknown_keys.count)}: #{unknown_keys.join(", ")}"
-    end
-
-    def error_context
-      "#{context}: " if context.present?
-    end
-
-    def with_context(context)
-      old_context = @context
-      @context = [ @context, context ].select(&:present?).join("/")
-      yield
-    ensure
-      @context = old_context
-    end
-
-    def allow_extensions?
-      false
-    end
-
-    def extension?(key)
-      key.to_s.start_with?("x-")
-    end
-
-    def check_unknown_keys!(config, example)
-      unknown_keys = config.keys - example.keys
-      unknown_keys.reject! { |key| extension?(key) } if allow_extensions?
-      unknown_keys_error unknown_keys if unknown_keys.present?
-    end
-end
--- a/lib/kamal/configuration/validator/accessory.rb
+++ b/lib/kamal/configuration/validator/accessory.rb
@@ -1,9 +0,0 @@
-class Kamal::Configuration::Validator::Accessory < Kamal::Configuration::Validator
-  def validate!
-    super
-
-    if (config.keys & [ "host", "hosts", "roles" ]).size != 1
-      error "specify one of `host`, `hosts` or `roles`"
-    end
-  end
-end
--- a/lib/kamal/configuration/validator/builder.rb
+++ b/lib/kamal/configuration/validator/builder.rb
@@ -1,9 +0,0 @@
-class Kamal::Configuration::Validator::Builder < Kamal::Configuration::Validator
-  def validate!
-    super
-
-    if config["cache"] && config["cache"]["type"]
-      error "Invalid cache type: #{config["cache"]["type"]}" unless [ "gha", "registry" ].include?(config["cache"]["type"])
-    end
-  end
-end
--- a/lib/kamal/configuration/validator/configuration.rb
+++ b/lib/kamal/configuration/validator/configuration.rb
@@ -1,6 +0,0 @@
-class Kamal::Configuration::Validator::Configuration < Kamal::Configuration::Validator
-  private
-    def allow_extensions?
-      true
-    end
-end
--- a/lib/kamal/configuration/validator/env.rb
+++ b/lib/kamal/configuration/validator/env.rb
@@ -1,54 +0,0 @@
-class Kamal::Configuration::Validator::Env < Kamal::Configuration::Validator
-  SPECIAL_KEYS = [ "clear", "secret", "tags" ]
-
-  def validate!
-    if known_keys.any?
-      validate_complex_env!
-    else
-      validate_simple_env!
-    end
-  end
-
-  private
-    def validate_simple_env!
-      validate_hash_of!(config, String)
-    end
-
-    def validate_complex_env!
-      unknown_keys_error unknown_keys if unknown_keys.any?
-
-      with_context("clear") { validate_hash_of!(config["clear"], String) } if config.key?("clear")
-      with_context("secret") { validate_array_of!(config["secret"], String) } if config.key?("secret")
-      validate_tags! if config.key?("tags")
-    end
-
-    def known_keys
-      @known_keys ||= config.keys & SPECIAL_KEYS
-    end
-
-    def unknown_keys
-      @unknown_keys ||= config.keys - SPECIAL_KEYS
-    end
-
-    def validate_tags!
-      if context == "env"
-        with_context("tags") do
-          validate_type! config["tags"], Hash
-
-          config["tags"].each do |tag, value|
-            with_context(tag) do
-              validate_type! value, Hash
-
-              Kamal::Configuration::Validator::Env.new(
-                value,
-                example: example["tags"].values[1],
-                context: context
-              ).validate!
-            end
-          end
-        end
-      else
-        error "tags are only allowed in the root env"
-      end
-    end
-end
--- a/lib/kamal/configuration/validator/registry.rb
+++ b/lib/kamal/configuration/validator/registry.rb
@@ -1,25 +0,0 @@
-class Kamal::Configuration::Validator::Registry < Kamal::Configuration::Validator
-  STRING_OR_ONE_ITEM_ARRAY_KEYS = [ "username", "password" ]
-
-  def validate!
-    validate_against_example! \
-      config.except(*STRING_OR_ONE_ITEM_ARRAY_KEYS),
-      example.except(*STRING_OR_ONE_ITEM_ARRAY_KEYS)
-
-    validate_string_or_one_item_array! "username"
-    validate_string_or_one_item_array! "password"
-  end
-
-  private
-    def validate_string_or_one_item_array!(key)
-      with_context(key) do
-        value = config[key]
-
-        error "is required" unless value.present?
-
-        unless value.is_a?(String) || (value.is_a?(Array) && value.size == 1 && value.first.is_a?(String))
-          error "should be a string or an array with one string (for secret lookup)"
-        end
-      end
-    end
-end
--- a/lib/kamal/configuration/validator/role.rb
+++ b/lib/kamal/configuration/validator/role.rb
@@ -1,11 +0,0 @@
-class Kamal::Configuration::Validator::Role < Kamal::Configuration::Validator
-  def validate!
-    validate_type! config, Array, Hash
-
-    if config.is_a?(Array)
-      validate_servers! "servers", config
-    else
-      super
-    end
-  end
-end
--- a/lib/kamal/configuration/validator/servers.rb
+++ b/lib/kamal/configuration/validator/servers.rb
@@ -1,7 +0,0 @@
-class Kamal::Configuration::Validator::Servers < Kamal::Configuration::Validator
-  def validate!
-    validate_type! config, Array, Hash
-
-    validate_servers! config if config.is_a?(Array)
-  end
-end
--- a/lib/kamal/env_file.rb
+++ b/lib/kamal/env_file.rb
@@ -24,13 +24,6 @@ class Kamal::EnvFile

    # Escape a value to make it safe to dump in a docker file.
    def escape_docker_env_file_value(value)
-      # keep non-ascii(UTF-8) characters as it is
-      value.to_s.scan(/[\x00-\x7F]+|[^\x00-\x7F]+/).map do |part|
-        part.ascii_only? ? escape_docker_env_file_ascii_value(part) : part
-      end.join
-    end
-
-    def escape_docker_env_file_ascii_value(value)
      # Doublequotes are treated literally in docker env files
      # so remove leading and trailing ones and unescape any others
      value.to_s.dump[1..-2].gsub(/\\"/, "\"")
--- a/lib/kamal/git.rb
+++ b/lib/kamal/git.rb
@@ -9,10 +9,6 @@ module Kamal::Git
    `git config user.name`.strip
  end

-  def email
-    `git config user.email`.strip
-  end
-
  def revision
    `git rev-parse HEAD`.strip
  end
@@ -20,8 +16,4 @@ module Kamal::Git
  def uncommitted_changes
    `git status --porcelain`.strip
  end
-
-  def root
-    `git rev-parse --show-toplevel`.strip
-  end
 end
--- a/lib/kamal/sshkit_with_ext.rb
+++ b/lib/kamal/sshkit_with_ext.rb
@@ -103,39 +103,3 @@ class SSHKit::Backend::Netssh

  prepend LimitConcurrentStartsInstance
 end
-
-class SSHKit::Runner::Parallel
-  # SSHKit joins the threads in sequence and fails on the first error it encounters, which means that we wait threads
-  # before the first failure to complete but not for ones after.
-  #
-  # We'll patch it to wait for them all to complete, and to record all the threads that errored so we can see when a
-  # problem occurs on multiple hosts.
-  module CompleteAll
-    def execute
-      threads = hosts.map do |host|
-        Thread.new(host) do |h|
-          backend(h, &block).run
-        rescue ::StandardError => e
-          e2 = SSHKit::Runner::ExecuteError.new e
-          raise e2, "Exception while executing #{host.user ? "as #{host.user}@" : "on host "}#{host}: #{e.message}"
-        end
-      end
-
-      exceptions = []
-      threads.each do |t|
-        begin
-          t.join
-        rescue SSHKit::Runner::ExecuteError => e
-          exceptions << e
-        end
-      end
-      if exceptions.one?
-        raise exceptions.first
-      elsif exceptions.many?
-        raise exceptions.first, [ "Exceptions on #{exceptions.count} hosts:", exceptions.map(&:message) ].join("\n")
-      end
-    end
-  end
-
-  prepend CompleteAll
-end
--- a/lib/kamal/tags.rb
+++ b/lib/kamal/tags.rb
@@ -10,11 +10,10 @@ class Kamal::Tags

    def default_tags(config)
      { recorded_at: Time.now.utc.iso8601,
-        performer: Kamal::Git.email.presence || `whoami`.chomp,
+        performer: `whoami`.chomp,
        destination: config.destination,
        version: config.version,
-        service_version: service_version(config),
-        service: config.service }
+        service_version: service_version(config) }
    end

    def service_version(config)
--- a/lib/kamal/utils.rb
+++ b/lib/kamal/utils.rb
@@ -66,15 +66,12 @@ module Kamal::Utils
    Array(filters).select do |filter|
      matches += Array(items).select do |item|
        # Only allow * for a wildcard
+        pattern = Regexp.escape(filter).gsub('\*', ".*")
        # items are roles or hosts
-        File.fnmatch(filter, item.to_s, File::FNM_EXTGLOB)
+        (item.respond_to?(:name) ? item.name : item).match(/^#{pattern}$/)
      end
    end

-    matches.uniq
-  end
-
-  def stable_sort!(elements, &block)
-    elements.sort_by!.with_index { |element, index| [ block.call(element), index ] }
+    matches
  end
 end
--- a/lib/kamal/version.rb
+++ b/lib/kamal/version.rb
@@ -1,3 +1,3 @@
 module Kamal
-  VERSION = "1.9.0"
+  VERSION = "1.4.0"
 end
--- a/test/cli/accessory_test.rb
+++ b/test/cli/accessory_test.rb
@@ -76,10 +76,7 @@ class CliAccessoryTest < CliTestCase
  end

  test "details" do
-    run_command("details", "mysql").tap do |output|
-      assert_match "docker ps --filter label=service=app-mysql", output
-      assert_match "Accessory mysql Host: 1.1.1.3", output
-    end
+    assert_match "docker ps --filter label=service=app-mysql", run_command("details", "mysql")
  end

  test "details with non-existent accessory" do
@@ -88,8 +85,6 @@ class CliAccessoryTest < CliTestCase

  test "details with all" do
    run_command("details", "all").tap do |output|
-      assert_match "Accessory mysql Host: 1.1.1.3", output
-      assert_match "Accessory redis Host: 1.1.1.2", output
      assert_match "docker ps --filter label=service=app-mysql", output
      assert_match "docker ps --filter label=service=app-redis", output
    end
@@ -116,20 +111,6 @@ class CliAccessoryTest < CliTestCase
    assert_match "docker logs app-mysql  --tail 100 --timestamps 2>&1", run_command("logs", "mysql")
  end

-  test "logs with grep" do
-    SSHKit::Backend::Abstract.any_instance.stubs(:exec)
-      .with("ssh -t root@1.1.1.3 'docker logs app-mysql --timestamps 2>&1 | grep \'hey\''")
-
-    assert_match "docker logs app-mysql --timestamps 2>&1 | grep 'hey'", run_command("logs", "mysql", "--grep", "hey")
-  end
-
-  test "logs with grep and grep options" do
-    SSHKit::Backend::Abstract.any_instance.stubs(:exec)
-      .with("ssh -t root@1.1.1.3 'docker logs app-mysql --timestamps 2>&1 | grep \'hey\' -C 2'")
-
-    assert_match "docker logs app-mysql --timestamps 2>&1 | grep 'hey' -C 2", run_command("logs", "mysql", "--grep", "hey", "--grep-options", "-C 2")
-  end
-
  test "logs with follow" do
    SSHKit::Backend::Abstract.any_instance.stubs(:exec)
      .with("ssh -t root@1.1.1.3 -p 22 'docker logs app-mysql --timestamps --tail 10 --follow 2>&1'")
@@ -137,20 +118,6 @@ class CliAccessoryTest < CliTestCase
    assert_match "docker logs app-mysql --timestamps --tail 10 --follow 2>&1", run_command("logs", "mysql", "--follow")
  end

-  test "logs with follow and grep" do
-    SSHKit::Backend::Abstract.any_instance.stubs(:exec)
-      .with("ssh -t root@1.1.1.3 -p 22 'docker logs app-mysql --timestamps --tail 10 --follow 2>&1 | grep \"hey\"'")
-
-    assert_match "docker logs app-mysql --timestamps --tail 10 --follow 2>&1 | grep \"hey\"", run_command("logs", "mysql", "--follow", "--grep", "hey")
-  end
-
-  test "logs with follow, grep, and grep options" do
-    SSHKit::Backend::Abstract.any_instance.stubs(:exec)
-      .with("ssh -t root@1.1.1.3 -p 22 'docker logs app-mysql --timestamps --tail 10 --follow 2>&1 | grep \"hey\" -C 2'")
-
-    assert_match "docker logs app-mysql --timestamps --tail 10 --follow 2>&1 | grep \"hey\" -C 2", run_command("logs", "mysql", "--follow", "--grep", "hey", "--grep-options", "-C 2")
-  end
-
  test "remove with confirmation" do
    Kamal::Cli::Accessory.any_instance.expects(:stop).with("mysql")
    Kamal::Cli::Accessory.any_instance.expects(:remove_container).with("mysql")
@@ -209,24 +176,6 @@ class CliAccessoryTest < CliTestCase
    end
  end

-  test "downgrade" do
-    run_command("downgrade", "-y", "all").tap do |output|
-      assert_match "Downgrading all accessories on 1.1.1.3,1.1.1.1,1.1.1.2...", output
-      assert_match "docker container stop app-mysql on 1.1.1.3", output
-      assert_match "docker run --name app-mysql --detach --restart unless-stopped --log-opt max-size=\"10m\" --publish 3306:3306 --env-file .kamal/env/accessories/app-mysql.env --env MYSQL_ROOT_HOST=\"%\" --volume $PWD/app-mysql/etc/mysql/my.cnf:/etc/mysql/my.cnf --volume $PWD/app-mysql/data:/var/lib/mysql --label service=\"app-mysql\" mysql:5.7 on 1.1.1.3", output
-      assert_match "Downgraded all accessories on 1.1.1.3,1.1.1.1,1.1.1.2", output
-    end
-  end
-
-  test "downgrade rolling" do
-    run_command("downgrade", "--rolling", "-y", "all").tap do |output|
-      assert_match "Downgrading all accessories on 1.1.1.3...", output
-      assert_match "docker container stop app-mysql on 1.1.1.3", output
-      assert_match "docker run --name app-mysql --detach --restart unless-stopped --log-opt max-size=\"10m\" --publish 3306:3306 --env-file .kamal/env/accessories/app-mysql.env --env MYSQL_ROOT_HOST=\"%\" --volume $PWD/app-mysql/etc/mysql/my.cnf:/etc/mysql/my.cnf --volume $PWD/app-mysql/data:/var/lib/mysql --label service=\"app-mysql\" mysql:5.7 on 1.1.1.3", output
-      assert_match "Downgraded all accessories on 1.1.1.3", output
-    end
-  end
-
  private
    def run_command(*command)
      stdouted { Kamal::Cli::Accessory.start([ *command, "-c", "test/fixtures/deploy_with_accessories.yml" ]) }
--- a/test/cli/app_test.rb
+++ b/test/cli/app_test.rb
@@ -23,7 +23,7 @@ class CliAppTest < CliTestCase
      .returns("running") # health check

    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:sh, "-c", "'docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''{{.ID}}'\\'') ; docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting'", "|", :head, "-1", "|", "while read line; do echo ${line#app-web-}; done", raise_on_non_zero_exit: false)
+      .with(:docker, :ps, "--filter", "label=service=app", "--filter", "label=role=web", "--filter", "status=running", "--filter", "status=restarting", "--latest", "--format", "\"{{.Names}}\"", "|", "while read line; do echo ${line#app-web-}; done", raise_on_non_zero_exit: false)
      .returns("123") # old version

    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
@@ -45,7 +45,7 @@ class CliAppTest < CliTestCase
  end

  test "boot uses group strategy when specified" do
-    Kamal::Cli::App.any_instance.stubs(:on).with("1.1.1.1").times(3) # ensure locks dir, acquire & release lock
+    Kamal::Cli::App.any_instance.stubs(:on).with("1.1.1.1").twice # acquire & release lock
    Kamal::Cli::App.any_instance.stubs(:on).with([ "1.1.1.1" ]) # tag container

    # Strategy is used when booting the containers
@@ -54,14 +54,14 @@ class CliAppTest < CliTestCase
    run_command("boot", config: :with_boot_strategy)
  end

-  test "boot errors don't leave lock in place" do
+  test "boot errors leave lock in place" do
    Kamal::Cli::App.any_instance.expects(:using_version).raises(RuntimeError)

    assert_not KAMAL.holding_lock?
    assert_raises(RuntimeError) do
      stderred { run_command("boot") }
    end
-    assert_not KAMAL.holding_lock?
+    assert KAMAL.holding_lock?
  end

  test "boot with assets" do
@@ -75,7 +75,7 @@ class CliAppTest < CliTestCase
      .returns("running") # health check

    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:sh, "-c", "'docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''{{.ID}}'\\'') ; docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting'", "|", :head, "-1", "|", "while read line; do echo ${line#app-web-}; done", raise_on_non_zero_exit: false)
+      .with(:docker, :ps, "--filter", "label=service=app", "--filter", "label=role=web", "--filter", "status=running", "--filter", "status=restarting", "--latest", "--format", "\"{{.Names}}\"", "|", "while read line; do echo ${line#app-web-}; done", raise_on_non_zero_exit: false)
      .returns("123").twice # old version

    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
@@ -92,82 +92,6 @@ class CliAppTest < CliTestCase
    end
  end

-  test "boot with host tags" do
-    Object.any_instance.stubs(:sleep)
-
-    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-    .with(:docker, :container, :ls, "--all", "--filter", "name=^app-web-latest$", "--quiet", raise_on_non_zero_exit: false)
-    .returns("12345678") # running version
-
-    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:docker, :container, :ls, "--all", "--filter", "name=^app-web-latest$", "--quiet", "|", :xargs, :docker, :inspect, "--format", "'{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}'")
-      .returns("running") # health check
-
-    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:sh, "-c", "'docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''{{.ID}}'\\'') ; docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting'", "|", :head, "-1", "|", "while read line; do echo ${line#app-web-}; done", raise_on_non_zero_exit: false)
-      .returns("123") # old version
-
-    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:docker, :inspect, "-f '{{ range .Mounts }}{{printf \"%s %s\\n\" .Source .Destination}}{{ end }}'", "app-web-123", "|", :awk, "'$2 == \"/tmp/kamal-cord\" {print $1}'", raise_on_non_zero_exit: false)
-      .returns("") # old version
-
-    run_command("boot", config: :with_env_tags).tap do |output|
-      assert_match "docker tag dhh/app:latest dhh/app:latest", output
-      assert_match %r{docker run --detach --restart unless-stopped --name app-web-latest --hostname 1.1.1.1-[0-9a-f]{12} -e KAMAL_CONTAINER_NAME="app-web-latest" -e KAMAL_VERSION="latest" --env-file .kamal/env/roles/app-web.env --env TEST="root" --env EXPERIMENT="disabled" --env SITE="site1"}, output
-      assert_match "docker container ls --all --filter name=^app-web-123$ --quiet | xargs docker stop", output
-    end
-  end
-
-  test "boot with web barrier opened" do
-    Object.any_instance.stubs(:sleep)
-
-    SSHKit::Backend::Abstract.any_instance.stubs(:capture_with_info).returns("123") # old version
-
-    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:docker, :container, :ls, "--all", "--filter", "name=^app-web-latest$", "--quiet", "|", :xargs, :docker, :inspect, "--format", "'{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}'")
-      .returns("running").at_least_once # web health check passing
-
-    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:docker, :container, :ls, "--all", "--filter", "name=^app-web-123$", "--quiet", "|", :xargs, :docker, :inspect, "--format", "'{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}'")
-      .returns("unhealthy").at_least_once # web health check failing
-
-    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:docker, :container, :ls, "--all", "--filter", "name=^app-workers-latest$", "--quiet", "|", :xargs, :docker, :inspect, "--format", "'{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}'")
-      .returns("running").at_least_once # workers health check
-
-    run_command("boot", config: :with_roles, host: nil).tap do |output|
-      assert_match "Waiting for the first healthy web container before booting workers on 1.1.1.3...", output
-      assert_match "Waiting for the first healthy web container before booting workers on 1.1.1.4...", output
-      assert_match "First web container is healthy, booting workers on 1.1.1.3", output
-      assert_match "First web container is healthy, booting workers on 1.1.1.4", output
-  end
-  end
-
-  test "boot with web barrier closed" do
-    Thread.report_on_exception = false
-
-    Object.any_instance.stubs(:sleep)
-
-    SSHKit::Backend::Abstract.any_instance.stubs(:capture_with_info).returns("123") # old version
-
-    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:docker, :container, :ls, "--all", "--filter", "name=^app-web-latest$", "--quiet", "|", :xargs, :docker, :inspect, "--format", "'{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}'")
-      .returns("unhealthy").at_least_once # web health check failing
-
-    stderred do
-      run_command("boot", config: :with_roles, host: nil, allow_execute_error: true).tap do |output|
-        assert_match "Waiting for the first healthy web container before booting workers on 1.1.1.3...", output
-        assert_match "Waiting for the first healthy web container before booting workers on 1.1.1.4...", output
-        assert_match "First web container is unhealthy, not booting workers on 1.1.1.3", output
-        assert_match "First web container is unhealthy, not booting workers on 1.1.1.4", output
-        assert_match "Running docker container ls --all --filter name=^app-web-latest$ --quiet | xargs docker stop on 1.1.1.1", output
-        assert_match "Running docker container ls --all --filter name=^app-web-latest$ --quiet | xargs docker stop on 1.1.1.2", output
-      end
-    end
-  ensure
-    Thread.report_on_exception = true
-  end
-
  test "start" do
    run_command("start").tap do |output|
      assert_match "docker start app-web-999", output
@@ -176,18 +100,14 @@ class CliAppTest < CliTestCase

  test "stop" do
    run_command("stop").tap do |output|
-      assert_match "sh -c 'docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''{{.ID}}'\\'') ; docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting' | head -1 | xargs docker stop", output
+      assert_match "docker ps --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --latest | xargs docker stop", output
    end
  end

  test "stale_containers" do
    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
      .with(:docker, :ps, "--filter", "label=service=app", "--filter", "label=role=web", "--format", "\"{{.Names}}\"", "|", "while read line; do echo ${line#app-web-}; done", raise_on_non_zero_exit: false)
-      .returns("12345678\n87654321\n")
-
-    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:sh, "-c", "'docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''{{.ID}}'\\'') ; docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting'", "|", :head, "-1", "|", "while read line; do echo ${line#app-web-}; done", raise_on_non_zero_exit: false)
-      .returns("12345678\n")
+      .returns("12345678\n87654321")

    run_command("stale_containers").tap do |output|
      assert_match /Detected stale container for role web with version 87654321/, output
@@ -197,11 +117,7 @@ class CliAppTest < CliTestCase
  test "stop stale_containers" do
    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
      .with(:docker, :ps, "--filter", "label=service=app", "--filter", "label=role=web", "--format", "\"{{.Names}}\"", "|", "while read line; do echo ${line#app-web-}; done", raise_on_non_zero_exit: false)
-      .returns("12345678\n87654321\n")
-
-    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:sh, "-c", "'docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''{{.ID}}'\\'') ; docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting'", "|", :head, "-1", "|", "while read line; do echo ${line#app-web-}; done", raise_on_non_zero_exit: false)
-      .returns("12345678\n")
+      .returns("12345678\n87654321")

    run_command("stale_containers", "--stop").tap do |output|
      assert_match /Stopping stale container for role web with version 87654321/, output
@@ -217,7 +133,7 @@ class CliAppTest < CliTestCase

  test "remove" do
    run_command("remove").tap do |output|
-      assert_match /#{Regexp.escape("sh -c 'docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''{{.ID}}'\\'') ; docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting' | head -1 | xargs docker stop")}/, output
+      assert_match /#{Regexp.escape("docker ps --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --latest | xargs docker stop")}/, output
      assert_match /#{Regexp.escape("docker container prune --force --filter label=service=app")}/, output
      assert_match /#{Regexp.escape("docker image prune --all --force --filter label=service=app")}/, output
    end
@@ -249,7 +165,7 @@ class CliAppTest < CliTestCase

  test "exec with reuse" do
    run_command("exec", "--reuse", "ruby -v").tap do |output|
-      assert_match "sh -c 'docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''{{.ID}}'\\'') ; docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting' | head -1 | while read line; do echo ${line#app-web-}; done", output # Get current version
+      assert_match "docker ps --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --latest --format \"{{.Names}}\" | while read line; do echo ${line#app-web-}; done", output # Get current version
      assert_match "docker exec app-web-999 ruby -v", output
    end
  end
@@ -268,7 +184,7 @@ class CliAppTest < CliTestCase
      .with("ssh -t root@1.1.1.1 -p 22 'docker exec -it app-web-999 ruby -v'")
    run_command("exec", "-i", "--reuse", "ruby -v").tap do |output|
      assert_match "Get current version of running container...", output
-      assert_match "Running /usr/bin/env sh -c 'docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''{{.ID}}'\\'') ; docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting' | head -1 | while read line; do echo ${line#app-web-}; done on 1.1.1.1", output
+      assert_match "Running docker ps --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --latest --format \"{{.Names}}\" | while read line; do echo ${line#app-web-}; done on 1.1.1.1", output
      assert_match "Launching interactive command with version 999 via SSH from existing container on 1.1.1.1...", output
    end
  end
@@ -287,76 +203,34 @@ class CliAppTest < CliTestCase

  test "logs" do
    SSHKit::Backend::Abstract.any_instance.stubs(:exec)
-      .with("ssh -t root@1.1.1.1 'sh -c 'docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''{{.ID}}'\\'') ; docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting' | head -1| xargs docker logs --timestamps --tail 10 2>&1'")
+      .with("ssh -t root@1.1.1.1 'docker ps --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --latest| xargs docker logs --timestamps --tail 10 2>&1'")

-    assert_match "sh -c 'docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''{{.ID}}'\\'') ; docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting' | head -1 | xargs docker logs --tail 100 2>&1", run_command("logs")
-
-    assert_match "sh -c 'docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''{{.ID}}'\\'') ; docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting' | head -1 | xargs docker logs 2>&1 | grep 'hey'", run_command("logs", "--grep", "hey")
-
-    assert_match "sh -c 'docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''{{.ID}}'\\'') ; docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting' | head -1 | xargs docker logs 2>&1 | grep 'hey' -C 2", run_command("logs", "--grep", "hey", "--grep-options", "-C 2")
+    assert_match "docker ps --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --latest | xargs docker logs --tail 100 2>&1", run_command("logs")
  end

  test "logs with follow" do
    SSHKit::Backend::Abstract.any_instance.stubs(:exec)
-      .with("ssh -t root@1.1.1.1 -p 22 'sh -c '\\''docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''\\'\\'''\\''{{.ID}}'\\''\\'\\'''\\'') ; docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting'\\'' | head -1 | xargs docker logs --timestamps --tail 10 --follow 2>&1'")
+      .with("ssh -t root@1.1.1.1 -p 22 'docker ps --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --latest | xargs docker logs --timestamps --tail 10 --follow 2>&1'")

-    assert_match "sh -c '\\''docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''\\'\\'''\\''{{.ID}}'\\''\\'\\'''\\'') ; docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting'\\'' | head -1 | xargs docker logs --timestamps --tail 10 --follow 2>&1", run_command("logs", "--follow")
-  end
-
-  test "logs with follow and grep" do
-    SSHKit::Backend::Abstract.any_instance.stubs(:exec)
-      .with("ssh -t root@1.1.1.1 -p 22 'sh -c '\\''docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''\\'\\'''\\''{{.ID}}'\\''\\'\\'''\\'') ; docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting'\\'' | head -1 | xargs docker logs --timestamps --follow 2>&1 | grep \"hey\"'")
-
-    assert_match "sh -c '\\''docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''\\'\\'''\\''{{.ID}}'\\''\\'\\'''\\'') ; docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting'\\'' | head -1 | xargs docker logs --timestamps --follow 2>&1 | grep \"hey\"", run_command("logs", "--follow", "--grep", "hey")
-  end
-
-  test "logs with follow, grep and grep options" do
-    SSHKit::Backend::Abstract.any_instance.stubs(:exec)
-      .with("ssh -t root@1.1.1.1 -p 22 'sh -c '\\''docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''\\'\\'''\\''{{.ID}}'\\''\\'\\'''\\'') ; docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting'\\'' | head -1 | xargs docker logs --timestamps --follow 2>&1 | grep \"hey\" -C 2'")
-
-    assert_match "sh -c '\\''docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''\\'\\'''\\''{{.ID}}'\\''\\'\\'''\\'') ; docker ps --latest --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting'\\'' | head -1 | xargs docker logs --timestamps --follow 2>&1 | grep \"hey\" -C 2", run_command("logs", "--follow", "--grep", "hey", "--grep-options", "-C 2")
+    assert_match "docker ps --quiet --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --latest | xargs docker logs --timestamps --tail 10 --follow 2>&1", run_command("logs", "--follow")
  end

  test "version" do
    run_command("version").tap do |output|
-      assert_match "sh -c 'docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''{{.ID}}'\\'') ; docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting' | head -1 | while read line; do echo ${line#app-web-}; done", output
+      assert_match "docker ps --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --latest --format \"{{.Names}}\" | while read line; do echo ${line#app-web-}; done", output
    end
  end


  test "version through main" do
    stdouted { Kamal::Cli::Main.start([ "app", "version", "-c", "test/fixtures/deploy_with_accessories.yml", "--hosts", "1.1.1.1" ]) }.tap do |output|
-      assert_match "sh -c 'docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''{{.ID}}'\\'') ; docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting' | head -1 | while read line; do echo ${line#app-web-}; done", output
-    end
-  end
-
-  test "long hostname" do
-    stub_running
-
-    hostname = "this-hostname-is-really-unacceptably-long-to-be-honest.example.com"
-
-    stdouted { Kamal::Cli::App.start([ "boot", "-c", "test/fixtures/deploy_with_uncommon_hostnames.yml", "--hosts", hostname ]) }.tap do |output|
-      assert_match /docker run --detach --restart unless-stopped --name app-web-latest --hostname this-hostname-is-really-unacceptably-long-to-be-hon-[0-9a-f]{12} /, output
-    end
-  end
-
-  test "hostname is trimmed if will end with a period" do
-    stub_running
-
-    hostname = "this-hostname-with-random-part-is-too-long.example.com"
-
-    stdouted { Kamal::Cli::App.start([ "boot", "-c", "test/fixtures/deploy_with_uncommon_hostnames.yml", "--hosts", hostname ]) }.tap do |output|
-      assert_match /docker run --detach --restart unless-stopped --name app-web-latest --hostname this-hostname-with-random-part-is-too-long.example-[0-9a-f]{12} /, output
+      assert_match "docker ps --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --latest --format \"{{.Names}}\" | while read line; do echo ${line#app-web-}; done", output
    end
  end

  private
-    def run_command(*command, config: :with_accessories, host: "1.1.1.1", allow_execute_error: false)
-      stdouted do
-        Kamal::Cli::App.start([ *command, "-c", "test/fixtures/deploy_#{config}.yml", *([ "--hosts", host ] if host) ])
-      rescue SSHKit::Runner::ExecuteError => e
-        raise e unless allow_execute_error
-      end
+    def run_command(*command, config: :with_accessories)
+      stdouted { Kamal::Cli::App.start([ *command, "-c", "test/fixtures/deploy_#{config}.yml", "--hosts", "1.1.1.1" ]) }
    end

    def stub_running
--- a/test/cli/build_test.rb
+++ b/test/cli/build_test.rb
@@ -9,143 +9,29 @@ class CliBuildTest < CliTestCase
  end

  test "push" do
-    with_build_directory do |build_directory|
-      Kamal::Commands::Hook.any_instance.stubs(:hook_exists?).returns(true)
-      hook_variables = { version: 999, service_version: "app@999", hosts: "1.1.1.1,1.1.1.2,1.1.1.3,1.1.1.4", command: "build", subcommand: "push" }
-
-      SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-        .with(:git, "-C", anything, :"rev-parse", :HEAD)
-        .returns(Kamal::Git.revision)
-
-      SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-        .with(:git, "-C", anything, :status, "--porcelain")
-        .returns("")
-
-      SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-        .with(:docker, :buildx, :inspect, "kamal-app-multiarch", "> /dev/null")
-        .returns("")
-
-      run_command("push", "--verbose").tap do |output|
-        assert_hook_ran "pre-build", output, **hook_variables
-        assert_match /Cloning repo into build directory/, output
-        assert_match /git -C #{Dir.tmpdir}\/kamal-clones\/app-#{pwd_sha} clone #{Dir.pwd}/, output
-        assert_match /docker --version && docker buildx version/, output
-        assert_match /docker buildx build --push --platform linux\/amd64,linux\/arm64 --builder kamal-app-multiarch -t dhh\/app:999 -t dhh\/app:latest --label service="app" --file Dockerfile \. as .*@localhost/, output
-      end
-    end
-  end
-
-  test "push resetting clone" do
-    with_build_directory do |build_directory|
-      stub_setup
-
-      SSHKit::Backend::Abstract.any_instance.expects(:execute).with(:docker, "--version", "&&", :docker, :buildx, "version")
-
-      SSHKit::Backend::Abstract.any_instance.expects(:execute)
-        .with(:git, "-C", "#{Dir.tmpdir}/kamal-clones/app-#{pwd_sha}", :clone, Dir.pwd, "--recurse-submodules")
-        .raises(SSHKit::Command::Failed.new("fatal: destination path 'kamal' already exists and is not an empty directory"))
-        .then
-        .returns(true)
-      SSHKit::Backend::Abstract.any_instance.expects(:execute).with(:git, "-C", build_directory, :remote, "set-url", :origin, Dir.pwd)
-      SSHKit::Backend::Abstract.any_instance.expects(:execute).with(:git, "-C", build_directory, :fetch, :origin)
-      SSHKit::Backend::Abstract.any_instance.expects(:execute).with(:git, "-C", build_directory, :reset, "--hard", Kamal::Git.revision)
-      SSHKit::Backend::Abstract.any_instance.expects(:execute).with(:git, "-C", build_directory, :clean, "-fdx")
-      SSHKit::Backend::Abstract.any_instance.expects(:execute).with(:git, "-C", build_directory, :submodule, :update, "--init")
-
-      SSHKit::Backend::Abstract.any_instance.expects(:execute)
-        .with(:docker, :buildx, :build, "--push", "--platform", "linux/amd64,linux/arm64", "--builder", "kamal-app-multiarch", "-t", "dhh/app:999", "-t", "dhh/app:latest", "--label", "service=\"app\"", "--file", "Dockerfile", ".")
-
-      SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-        .with(:git, "-C", anything, :"rev-parse", :HEAD)
-        .returns(Kamal::Git.revision)
-
-      SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-        .with(:git, "-C", anything, :status, "--porcelain")
-        .returns("")
-
-      run_command("push", "--verbose").tap do |output|
-        assert_match /Cloning repo into build directory/, output
-        assert_match /Resetting local clone/, output
-      end
-    end
-  end
-
-  test "push without clone" do
    Kamal::Commands::Hook.any_instance.stubs(:hook_exists?).returns(true)
    hook_variables = { version: 999, service_version: "app@999", hosts: "1.1.1.1,1.1.1.2,1.1.1.3,1.1.1.4", command: "build", subcommand: "push" }

-    run_command("push", "--verbose", fixture: :without_clone).tap do |output|
-      assert_no_match /Cloning repo into build directory/, output
+    run_command("push").tap do |output|
      assert_hook_ran "pre-build", output, **hook_variables
      assert_match /docker --version && docker buildx version/, output
-      assert_match /docker buildx build --push --platform linux\/amd64,linux\/arm64 --builder kamal-app-multiarch -t dhh\/app:999 -t dhh\/app:latest --label service="app" --file Dockerfile . as .*@localhost/, output
-    end
-  end
-
-  test "push with corrupt clone" do
-    with_build_directory do |build_directory|
-      stub_setup
-
-      SSHKit::Backend::Abstract.any_instance.expects(:execute).with(:docker, "--version", "&&", :docker, :buildx, "version")
-
-      SSHKit::Backend::Abstract.any_instance.expects(:execute)
-        .with(:git, "-C", "#{Dir.tmpdir}/kamal-clones/app-#{pwd_sha}", :clone, Dir.pwd, "--recurse-submodules")
-        .raises(SSHKit::Command::Failed.new("fatal: destination path 'kamal' already exists and is not an empty directory"))
-        .then
-        .returns(true)
-        .twice
-
-      SSHKit::Backend::Abstract.any_instance.expects(:execute).with(:git, "-C", build_directory, :remote, "set-url", :origin, Dir.pwd)
-        .raises(SSHKit::Command::Failed.new("fatal: not a git repository"))
-
-      SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-        .with(:git, "-C", anything, :"rev-parse", :HEAD)
-        .returns(Kamal::Git.revision)
-
-      SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-        .with(:git, "-C", anything, :status, "--porcelain")
-        .returns("")
-
-      Dir.stubs(:chdir)
-
-      run_command("push", "--verbose") do |output|
-        assert_match /Cloning repo into build directory `#{build_directory}`\.\.\..*Cloning repo into build directory `#{build_directory}`\.\.\./, output
-        assert_match "Resetting local clone as `#{build_directory}` already exists...", output
-        assert_match "Error preparing clone: Failed to clone repo: fatal: not a git repository, deleting and retrying...", output
-      end
+      assert_match /docker buildx build --push --platform linux\/amd64,linux\/arm64 --builder kamal-app-multiarch -t dhh\/app:999 -t dhh\/app:latest --label service="app" --file Dockerfile \. as .*@localhost/, output
    end
  end

  test "push without builder" do
-    with_build_directory do |build_directory|
-      stub_setup
+    stub_setup
+    SSHKit::Backend::Abstract.any_instance.stubs(:execute)
+      .with(:docker, "--version", "&&", :docker, :buildx, "version")

-      SSHKit::Backend::Abstract.any_instance.expects(:execute)
-        .with(:docker, "--version", "&&", :docker, :buildx, "version")
+    SSHKit::Backend::Abstract.any_instance.stubs(:execute)
+      .with { |*args| args[0..1] == [ :docker, :buildx ] }
+      .raises(SSHKit::Command::Failed.new("no builder"))
+      .then
+      .returns(true)

-      SSHKit::Backend::Abstract.any_instance.expects(:execute)
-        .with(:docker, :buildx, :create, "--use", "--name", "kamal-app-multiarch")
-
-      SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-        .with(:docker, :buildx, :inspect, "kamal-app-multiarch", "> /dev/null")
-        .raises(SSHKit::Command::Failed.new("no builder"))
-
-      SSHKit::Backend::Abstract.any_instance.expects(:execute).with { |*args| args.first.start_with?("git") }
-
-      SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-        .with(:git, "-C", anything, :"rev-parse", :HEAD)
-        .returns(Kamal::Git.revision)
-
-      SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-        .with(:git, "-C", anything, :status, "--porcelain")
-        .returns("")
-
-      SSHKit::Backend::Abstract.any_instance.expects(:execute)
-        .with(:docker, :buildx, :build, "--push", "--platform", "linux/amd64,linux/arm64", "--builder", "kamal-app-multiarch", "-t", "dhh/app:999", "-t", "dhh/app:latest", "--label", "service=\"app\"", "--file", "Dockerfile", ".")
-
-      run_command("push").tap do |output|
-        assert_match /WARN Missing compatible builder, so creating a new one first/, output
-      end
+    run_command("push").tap do |output|
+      assert_match /Missing compatible builder, so creating a new one first/, output
    end
  end

@@ -162,49 +48,19 @@ class CliBuildTest < CliTestCase
  test "push pre-build hook failure" do
    fail_hook("pre-build")

-    error = assert_raises(Kamal::Cli::HookError) { run_command("push") }
-    assert_equal "Hook `pre-build` failed:\nfailed", error.message
+    assert_raises(Kamal::Cli::HookError) { run_command("push") }

    assert @executions.none? { |args| args[0..2] == [ :docker, :buildx, :build ] }
  end

  test "pull" do
    run_command("pull").tap do |output|
-      assert_match /docker info --format '{{index .RegistryConfig.Mirrors 0}}'/, output
      assert_match /docker image rm --force dhh\/app:999/, output
      assert_match /docker pull dhh\/app:999/, output
      assert_match "docker inspect -f '{{ .Config.Labels.service }}' dhh/app:999 | grep -x app || (echo \"Image dhh/app:999 is missing the 'service' label\" && exit 1)", output
    end
  end

-  test "pull with mirror" do
-    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:docker, :info, "--format '{{index .RegistryConfig.Mirrors 0}}'")
-      .returns("registry-mirror.example.com")
-      .at_least_once
-
-    run_command("pull").tap do |output|
-      assert_match /Pulling image on 1\.1\.1\.\d to seed the mirror\.\.\./, output
-      assert_match "Pulling image on remaining hosts...", output
-      assert_equal 4, output.scan(/docker pull dhh\/app:999/).size, output
-      assert_match "docker inspect -f '{{ .Config.Labels.service }}' dhh/app:999 | grep -x app || (echo \"Image dhh/app:999 is missing the 'service' label\" && exit 1)", output
-    end
-  end
-
-  test "pull with mirrors" do
-    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:docker, :info, "--format '{{index .RegistryConfig.Mirrors 0}}'")
-      .returns("registry-mirror.example.com", "registry-mirror2.example.com")
-      .at_least_once
-
-    run_command("pull").tap do |output|
-      assert_match /Pulling image on 1\.1\.1\.\d, 1\.1\.1\.\d to seed the mirrors\.\.\./, output
-      assert_match "Pulling image on remaining hosts...", output
-      assert_equal 4, output.scan(/docker pull dhh\/app:999/).size, output
-      assert_match "docker inspect -f '{{ .Config.Labels.service }}' dhh/app:999 | grep -x app || (echo \"Image dhh/app:999 is missing the 'service' label\" && exit 1)", output
-    end
-  end
-
  test "create" do
    run_command("create").tap do |output|
      assert_match /docker buildx create --use --name kamal-app-multiarch/, output
@@ -219,14 +75,6 @@ class CliBuildTest < CliTestCase
    end
  end

-  test "create remote with custom ports" do
-    run_command("create", fixture: :with_remote_builder_and_custom_ports).tap do |output|
-      assert_match "Running /usr/bin/env true on 1.1.1.5", output
-      assert_match "docker context create kamal-app-native-remote-amd64 --description 'kamal-app-native-remote amd64 native host' --docker 'host=ssh://app@1.1.1.5:2122'", output
-      assert_match "docker buildx create --name kamal-app-native-remote kamal-app-native-remote-amd64 --platform linux/amd64", output
-    end
-  end
-
  test "create with error" do
    stub_setup
    SSHKit::Backend::Abstract.any_instance.stubs(:execute)
@@ -266,17 +114,4 @@ class CliBuildTest < CliTestCase
      SSHKit::Backend::Abstract.any_instance.stubs(:execute)
        .with { |*args| args[0..1] == [ :docker, :buildx ] }
    end
-
-    def with_build_directory
-      build_directory = File.join Dir.tmpdir, "kamal-clones", "app-#{pwd_sha}", "kamal"
-      FileUtils.mkdir_p build_directory
-      FileUtils.touch File.join build_directory, "Dockerfile"
-      yield build_directory + "/"
-    ensure
-      FileUtils.rm_rf build_directory
-    end
-
-    def pwd_sha
-      Digest::SHA256.hexdigest(Dir.pwd)[0..12]
-    end
 end
--- a/test/cli/cli_test_case.rb
+++ b/test/cli/cli_test_case.rb
@@ -31,34 +31,26 @@ class CliTestCase < ActiveSupport::TestCase
      SSHKit::Backend::Abstract.any_instance.stubs(:execute)
        .with { |*args| args == [ :mkdir, "-p", ".kamal" ] }
      SSHKit::Backend::Abstract.any_instance.stubs(:execute)
-        .with { |arg1, arg2, arg3| arg1 == :mkdir && arg2 == "-p" && arg3 == ".kamal/locks" }
+        .with { |arg1, arg2| arg1 == :mkdir && arg2 == ".kamal/lock-app" }
      SSHKit::Backend::Abstract.any_instance.stubs(:execute)
-        .with { |arg1, arg2| arg1 == :mkdir && arg2 == ".kamal/locks/app" }
-      SSHKit::Backend::Abstract.any_instance.stubs(:execute)
-        .with { |arg1, arg2| arg1 == :rm && arg2 == ".kamal/locks/app/details" }
-      SSHKit::Backend::Abstract.any_instance.stubs(:capture_with_info)
-        .with { |*args| args[0..2] == [ :docker, :buildx, :inspect ] }
-        .returns("")
+        .with { |arg1, arg2| arg1 == :rm && arg2 == ".kamal/lock-app/details" }
    end

-    def assert_hook_ran(hook, output, version:, service_version:, hosts:, command:, subcommand: nil, runtime: false)
-      whoami = `whoami`.chomp
-      performer = Kamal::Git.email.presence || whoami
-      service = service_version.split("@").first
+    def assert_hook_ran(hook, output, version:, service_version:, hosts:, command:, subcommand: nil, runtime: nil)
+      performer = `whoami`.strip

      assert_match "Running the #{hook} hook...\n", output

-      expected = %r{Running\s/usr/bin/env\s\.kamal/hooks/#{hook}\sas\s#{whoami}@localhost\n\s
+      expected = %r{Running\s/usr/bin/env\s\.kamal/hooks/#{hook}\sas\s#{performer}@localhost\n\s
        DEBUG\s\[[0-9a-f]*\]\sCommand:\s\(\sexport\s
        KAMAL_RECORDED_AT=\"\d\d\d\d-\d\d-\d\dT\d\d:\d\d:\d\dZ\"\s
        KAMAL_PERFORMER=\"#{performer}\"\s
        KAMAL_VERSION=\"#{version}\"\s
        KAMAL_SERVICE_VERSION=\"#{service_version}\"\s
-        KAMAL_SERVICE=\"#{service}\"\s
        KAMAL_HOSTS=\"#{hosts}\"\s
        KAMAL_COMMAND=\"#{command}\"\s
        #{"KAMAL_SUBCOMMAND=\\\"#{subcommand}\\\"\\s" if subcommand}
-        #{"KAMAL_RUNTIME=\\\"\\d+\\\"\\s" if runtime}
+        #{"KAMAL_RUNTIME=\\\"#{runtime}\\\"\\s" if runtime}
        ;\s/usr/bin/env\s\.kamal/hooks/#{hook} }x

      assert_match expected, output
--- a/test/cli/healthcheck_test.rb
+++ b/test/cli/healthcheck_test.rb
@@ -0,0 +1,82 @@
+require_relative "cli_test_case"
+
+class CliHealthcheckTest < CliTestCase
+  test "perform" do
+    # Prevent expected failures from outputting to terminal
+    Thread.report_on_exception = false
+
+    Kamal::Cli::Healthcheck::Poller.stubs(:sleep) # No sleeping when retrying
+    Kamal::Configuration.any_instance.stubs(:run_id).returns("12345678901234567890123456789012")
+
+    SSHKit::Backend::Abstract.any_instance.stubs(:execute)
+      .with(:docker, :container, :ls, "--all", "--filter", "name=^healthcheck-app-999$", "--quiet", "|", :xargs, :docker, :stop, raise_on_non_zero_exit: false)
+    SSHKit::Backend::Abstract.any_instance.stubs(:execute)
+      .with(:docker, :run, "--detach", "--name", "healthcheck-app-999", "--publish", "3999:3000", "--label", "service=healthcheck-app", "-e", "KAMAL_CONTAINER_NAME=\"healthcheck-app\"", "--env-file", ".kamal/env/roles/app-web.env", "--health-cmd", "\"curl -f http://localhost:3000/up || exit 1\"", "--health-interval", "\"1s\"", "dhh/app:999")
+    SSHKit::Backend::Abstract.any_instance.stubs(:execute)
+      .with(:docker, :container, :ls, "--all", "--filter", "name=^healthcheck-app-999$", "--quiet", "|", :xargs, :docker, :container, :rm, raise_on_non_zero_exit: false)
+
+    # Fail twice to test retry logic
+    SSHKit::Backend::Abstract.any_instance.stubs(:capture_with_info)
+      .with(:docker, :container, :ls, "--all", "--filter", "name=^healthcheck-app-999$", "--quiet", "|", :xargs, :docker, :inspect, "--format", "'{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}'")
+      .returns("starting")
+      .then
+      .returns("unhealthy")
+      .then
+      .returns("healthy")
+
+    run_command("perform").tap do |output|
+      assert_match "container not ready (starting), retrying in 1s (attempt 1/7)...", output
+      assert_match "container not ready (unhealthy), retrying in 2s (attempt 2/7)...", output
+      assert_match "Container is healthy!", output
+    end
+  end
+
+  test "perform failing to become healthy" do
+    # Prevent expected failures from outputting to terminal
+    Thread.report_on_exception = false
+
+    Kamal::Cli::Healthcheck::Poller.stubs(:sleep) # No sleeping when retrying
+
+    SSHKit::Backend::Abstract.any_instance.stubs(:execute)
+      .with(:docker, :container, :ls, "--all", "--filter", "name=^healthcheck-app-999$", "--quiet", "|", :xargs, :docker, :stop, raise_on_non_zero_exit: false)
+    SSHKit::Backend::Abstract.any_instance.stubs(:execute)
+      .with(:docker, :run, "--detach", "--name", "healthcheck-app-999", "--publish", "3999:3000", "--label", "service=healthcheck-app", "-e", "KAMAL_CONTAINER_NAME=\"healthcheck-app\"", "--env-file", ".kamal/env/roles/app-web.env", "--health-cmd", "\"curl -f http://localhost:3000/up || exit 1\"", "--health-interval", "\"1s\"", "dhh/app:999")
+    SSHKit::Backend::Abstract.any_instance.stubs(:execute)
+      .with(:docker, :container, :ls, "--all", "--filter", "name=^healthcheck-app-999$", "--quiet", "|", :xargs, :docker, :container, :rm, raise_on_non_zero_exit: false)
+
+    # Continually report unhealthy
+    SSHKit::Backend::Abstract.any_instance.stubs(:capture_with_info)
+      .with(:docker, :container, :ls, "--all", "--filter", "name=^healthcheck-app-999$", "--quiet", "|", :xargs, :docker, :inspect, "--format", "'{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}'")
+      .returns("unhealthy")
+
+    # Capture logs when failing
+    SSHKit::Backend::Abstract.any_instance.stubs(:capture_with_info)
+      .with(:docker, :container, :ls, "--all", "--filter", "name=^healthcheck-app-999$", "--quiet", "|", :xargs, :docker, :logs, "--tail", 50, "2>&1")
+      .returns("some log output")
+
+    # Capture container health log when failing
+    SSHKit::Backend::Abstract.any_instance.stubs(:capture_with_pretty_json)
+      .with(:docker, :container, :ls, "--all", "--filter", "name=^healthcheck-app-999$", "--quiet", "|", :xargs, :docker, :inspect, "--format",  "'{{json .State.Health}}'")
+      .returns('{"Status":"unhealthy","Log":[{"ExitCode": 1,"Output": "/bin/sh: 1: curl: not found\n"}]}"')
+
+    exception = assert_raises do
+      run_command("perform")
+    end
+    assert_match "container not ready (unhealthy)", exception.message
+  end
+
+  test "raises an exception if primary does not have traefik" do
+    SSHKit::Backend::Abstract.any_instance.expects(:execute).never
+
+    exception = assert_raises do
+      run_command("perform", config_file: "test/fixtures/deploy_workers_only.yml")
+    end
+
+    assert_equal "The primary host is not configured to run Traefik", exception.message
+  end
+
+  private
+    def run_command(*command, config_file: "test/fixtures/deploy_with_accessories.yml")
+      stdouted { Kamal::Cli::Healthcheck.start([ *command, "-c", config_file ]) }
+    end
+end
--- a/test/cli/lock_test.rb
+++ b/test/cli/lock_test.rb
@@ -3,7 +3,7 @@ require_relative "cli_test_case"
 class CliLockTest < CliTestCase
  test "status" do
    run_command("status").tap do |output|
-      assert_match "Running /usr/bin/env stat .kamal/locks/app > /dev/null && cat .kamal/locks/app/details | base64 -d on 1.1.1.1", output
+      assert_match "Running /usr/bin/env stat .kamal/lock-app > /dev/null && cat .kamal/lock-app/details | base64 -d on 1.1.1.1", output
    end
  end

--- a/test/cli/main_test.rb
+++ b/test/cli/main_test.rb
@@ -1,21 +1,17 @@
 require_relative "cli_test_case"

 class CliMainTest < CliTestCase
-  setup { @original_env = ENV.to_h.dup }
-  teardown { ENV.clear; ENV.update @original_env }
-
  test "setup" do
    invoke_options = { "config_file" => "test/fixtures/deploy_simple.yml", "version" => "999", "skip_hooks" => false }

    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:server:bootstrap", [], invoke_options)
-    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:main:envify", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:env:push", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:accessory:boot", [ "all" ], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:deploy)

    run_command("setup").tap do |output|
      assert_match /Ensure Docker is installed.../, output
-      assert_match /Evaluate and push env files.../, output
+      assert_match /Push env files.../, output
    end
  end

@@ -24,24 +20,25 @@ class CliMainTest < CliTestCase

    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:server:bootstrap", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:env:push", [], invoke_options)
-    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:main:envify", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:accessory:boot", [ "all" ], invoke_options)
    # deploy
-    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:registry:login", [], invoke_options.merge(skip_local: true))
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:registry:login", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:build:pull", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:traefik:boot", [], invoke_options)
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:healthcheck:perform", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:stale_containers", [], invoke_options.merge(stop: true))
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:boot", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:prune:all", [], invoke_options)

    run_command("setup", "--skip_push").tap do |output|
      assert_match /Ensure Docker is installed.../, output
-      assert_match /Evaluate and push env files.../, output
+      assert_match /Push env files.../, output
      # deploy
      assert_match /Acquiring the deploy lock/, output
      assert_match /Log into image registry/, output
      assert_match /Pull app image/, output
      assert_match /Ensure Traefik is running/, output
+      assert_match /Ensure app can pass healthcheck/, output
      assert_match /Detect stale containers/, output
      assert_match /Prune old containers and images/, output
      assert_match /Releasing the deploy lock/, output
@@ -49,11 +46,12 @@ class CliMainTest < CliTestCase
  end

  test "deploy" do
-    invoke_options = { "config_file" => "test/fixtures/deploy_simple.yml", "version" => "999", "skip_hooks" => false, "verbose" => true }
+    invoke_options = { "config_file" => "test/fixtures/deploy_simple.yml", "version" => "999", "skip_hooks" => false }

-    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:registry:login", [], invoke_options.merge(skip_local: false))
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:registry:login", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:build:deliver", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:traefik:boot", [], invoke_options)
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:healthcheck:perform", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:stale_containers", [], invoke_options.merge(stop: true))
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:boot", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:prune:all", [], invoke_options)
@@ -61,24 +59,26 @@ class CliMainTest < CliTestCase
    Kamal::Commands::Hook.any_instance.stubs(:hook_exists?).returns(true)
    hook_variables = { version: 999, service_version: "app@999", hosts: "1.1.1.1,1.1.1.2", command: "deploy" }

-    run_command("deploy", "--verbose").tap do |output|
+    run_command("deploy").tap do |output|
      assert_hook_ran "pre-connect", output, **hook_variables
      assert_match /Log into image registry/, output
      assert_match /Build and push app image/, output
      assert_hook_ran "pre-deploy", output, **hook_variables
      assert_match /Ensure Traefik is running/, output
+      assert_match /Ensure app can pass healthcheck/, output
      assert_match /Detect stale containers/, output
      assert_match /Prune old containers and images/, output
-      assert_hook_ran "post-deploy", output, **hook_variables, runtime: true
+      assert_hook_ran "post-deploy", output, **hook_variables, runtime: 0
    end
  end

  test "deploy with skip_push" do
    invoke_options = { "config_file" => "test/fixtures/deploy_simple.yml", "version" => "999", "skip_hooks" => false }

-    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:registry:login", [], invoke_options.merge(skip_local: true))
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:registry:login", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:build:pull", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:traefik:boot", [], invoke_options)
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:healthcheck:perform", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:stale_containers", [], invoke_options.merge(stop: true))
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:boot", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:prune:all", [], invoke_options)
@@ -88,6 +88,7 @@ class CliMainTest < CliTestCase
      assert_match /Log into image registry/, output
      assert_match /Pull app image/, output
      assert_match /Ensure Traefik is running/, output
+      assert_match /Ensure app can pass healthcheck/, output
      assert_match /Detect stale containers/, output
      assert_match /Prune old containers and images/, output
      assert_match /Releasing the deploy lock/, output
@@ -97,38 +98,15 @@ class CliMainTest < CliTestCase
  test "deploy when locked" do
    Thread.report_on_exception = false

-    SSHKit::Backend::Abstract.any_instance.stubs(:execute)
-    Dir.stubs(:chdir)
-
    SSHKit::Backend::Abstract.any_instance.stubs(:execute)
      .with { |*args| args == [ :mkdir, "-p", ".kamal" ] }

    SSHKit::Backend::Abstract.any_instance.stubs(:execute)
-      .with { |*args| args == [ :mkdir, "-p", ".kamal/locks" ] }
-
-    SSHKit::Backend::Abstract.any_instance.stubs(:execute)
-      .with { |*arg| arg[0..1] == [ :mkdir, ".kamal/locks/app" ] }
-      .raises(RuntimeError, "mkdir: cannot create directory ‘kamal/locks/app’: File exists")
+      .with { |*arg| arg[0..1] == [ :mkdir, ".kamal/lock-app" ] }
+      .raises(RuntimeError, "mkdir: cannot create directory ‘kamal_lock-app’: File exists")

    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_debug)
-      .with(:stat, ".kamal/locks/app", ">", "/dev/null", "&&", :cat, ".kamal/locks/app/details", "|", :base64, "-d")
-
-    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:git, "-C", anything, :"rev-parse", :HEAD)
-      .returns(Kamal::Git.revision)
-
-    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:git, "-C", anything, :status, "--porcelain")
-      .returns("")
-
-    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:docker, :buildx, :inspect, "kamal-app-multiarch", "> /dev/null")
-      .returns("")
-
-    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:docker, :info, "--format '{{index .RegistryConfig.Mirrors 0}}'")
-      .returns("")
-      .at_least_once
+      .with(:stat, ".kamal/lock-app", ">", "/dev/null", "&&", :cat, ".kamal/lock-app/details", "|", :base64, "-d")

    assert_raises(Kamal::Cli::LockError) do
      run_command("deploy")
@@ -138,46 +116,23 @@ class CliMainTest < CliTestCase
  test "deploy error when locking" do
    Thread.report_on_exception = false

-    SSHKit::Backend::Abstract.any_instance.stubs(:execute)
-    Dir.stubs(:chdir)
-
    SSHKit::Backend::Abstract.any_instance.stubs(:execute)
      .with { |*args| args == [ :mkdir, "-p", ".kamal" ] }

    SSHKit::Backend::Abstract.any_instance.stubs(:execute)
-      .with { |*args| args == [ :mkdir, "-p", ".kamal/locks" ] }
-
-    SSHKit::Backend::Abstract.any_instance.stubs(:execute)
-      .with { |*arg| arg[0..1] == [ :mkdir, ".kamal/locks/app" ] }
+      .with { |*arg| arg[0..1] == [ :mkdir, ".kamal/lock-app" ] }
      .raises(SocketError, "getaddrinfo: nodename nor servname provided, or not known")

-    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:git, "-C", anything, :"rev-parse", :HEAD)
-      .returns(Kamal::Git.revision)
-
-    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:git, "-C", anything, :status, "--porcelain")
-      .returns("")
-
-    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:docker, :buildx, :inspect, "kamal-app-multiarch", "> /dev/null")
-      .returns("")
-
-    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:docker, :info, "--format '{{index .RegistryConfig.Mirrors 0}}'")
-      .returns("")
-      .at_least_once
-
    assert_raises(SSHKit::Runner::ExecuteError) do
      run_command("deploy")
    end
  end

  test "deploy errors during outside section leave remove lock" do
-    invoke_options = { "config_file" => "test/fixtures/deploy_simple.yml", "version" => "999", "skip_hooks" => false, :skip_local => false }
+    invoke_options = { "config_file" => "test/fixtures/deploy_simple.yml", "version" => "999", "skip_hooks" => false }

    Kamal::Cli::Main.any_instance.expects(:invoke)
-      .with("kamal:cli:registry:login", [], invoke_options.merge(skip_local: false))
+      .with("kamal:cli:registry:login", [], invoke_options)
      .raises(RuntimeError)

    assert_not KAMAL.holding_lock?
@@ -190,9 +145,10 @@ class CliMainTest < CliTestCase
  test "deploy with skipped hooks" do
    invoke_options = { "config_file" => "test/fixtures/deploy_simple.yml", "version" => "999", "skip_hooks" => true }

-    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:registry:login", [], invoke_options.merge(skip_local: false))
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:registry:login", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:build:deliver", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:traefik:boot", [], invoke_options)
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:healthcheck:perform", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:stale_containers", [], invoke_options.merge(stop: true))
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:boot", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:prune:all", [], invoke_options)
@@ -207,7 +163,7 @@ class CliMainTest < CliTestCase

    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:healthcheck:perform", [], invoke_options).never

-    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:registry:login", [], invoke_options.merge(skip_local: false))
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:registry:login", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:build:deliver", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:traefik:boot", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:stale_containers", [], invoke_options.merge(stop: true))
@@ -220,9 +176,10 @@ class CliMainTest < CliTestCase
  test "deploy with missing secrets" do
    invoke_options = { "config_file" => "test/fixtures/deploy_with_secrets.yml", "version" => "999", "skip_hooks" => false }

-    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:registry:login", [], invoke_options.merge(skip_local: false))
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:registry:login", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:build:deliver", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:traefik:boot", [], invoke_options)
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:healthcheck:perform", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:stale_containers", [], invoke_options.merge(stop: true))
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:boot", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:prune:all", [], invoke_options)
@@ -231,9 +188,10 @@ class CliMainTest < CliTestCase
  end

  test "redeploy" do
-    invoke_options = { "config_file" => "test/fixtures/deploy_simple.yml", "version" => "999", "skip_hooks" => false, "verbose" => true }
+    invoke_options = { "config_file" => "test/fixtures/deploy_simple.yml", "version" => "999", "skip_hooks" => false }

    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:build:deliver", [], invoke_options)
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:healthcheck:perform", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:stale_containers", [], invoke_options.merge(stop: true))
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:boot", [], invoke_options)

@@ -241,12 +199,13 @@ class CliMainTest < CliTestCase

    hook_variables = { version: 999, service_version: "app@999", hosts: "1.1.1.1,1.1.1.2", command: "redeploy" }

-    run_command("redeploy", "--verbose").tap do |output|
+    run_command("redeploy").tap do |output|
      assert_hook_ran "pre-connect", output, **hook_variables
      assert_match /Build and push app image/, output
      assert_hook_ran "pre-deploy", output, **hook_variables
      assert_match /Running the pre-deploy hook.../, output
-      assert_hook_ran "post-deploy", output, **hook_variables, runtime: true
+      assert_match /Ensure app can pass healthcheck/, output
+      assert_hook_ran "post-deploy", output, **hook_variables, runtime: "0"
    end
  end

@@ -254,11 +213,13 @@ class CliMainTest < CliTestCase
    invoke_options = { "config_file" => "test/fixtures/deploy_simple.yml", "version" => "999", "skip_hooks" => false }

    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:build:pull", [], invoke_options)
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:healthcheck:perform", [], invoke_options)
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:stale_containers", [], invoke_options.merge(stop: true))
    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:boot", [], invoke_options)

    run_command("redeploy", "--skip_push").tap do |output|
      assert_match /Pull app image/, output
+      assert_match /Ensure app can pass healthcheck/, output
    end
  end

@@ -283,7 +244,7 @@ class CliMainTest < CliTestCase
        .with(:docker, :container, :ls, "--all", "--filter", "name=^app-#{role}-123$", "--quiet")
        .returns("version-to-rollback\n").at_least_once
      SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-        .with(:sh, "-c", "'docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=#{role} --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''{{.ID}}'\\'') ; docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=#{role} --filter status=running --filter status=restarting'", "|", :head, "-1", "|", "while read line; do echo ${line#app-#{role}-}; done", raise_on_non_zero_exit: false)
+        .with(:docker, :ps, "--filter", "label=service=app", "--filter", "label=role=#{role}", "--filter", "status=running", "--filter", "status=restarting", "--latest", "--format", "\"{{.Names}}\"", "|", "while read line; do echo ${line#app-#{role}-}; done", raise_on_non_zero_exit: false)
        .returns("version-to-rollback\n").at_least_once
      SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
        .with(:docker, :container, :ls, "--all", "--filter", "name=^app-#{role}-123$", "--quiet", "|", :xargs, :docker, :inspect, "--format", "'{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}'")
@@ -301,12 +262,12 @@ class CliMainTest < CliTestCase
    Kamal::Commands::Hook.any_instance.stubs(:hook_exists?).returns(true)
    hook_variables = { version: 123, service_version: "app@123", hosts: "1.1.1.1,1.1.1.2,1.1.1.3,1.1.1.4", command: "rollback" }

-    run_command("rollback", "--verbose", "123", config_file: "deploy_with_accessories").tap do |output|
+    run_command("rollback", "123", config_file: "deploy_with_accessories").tap do |output|
      assert_hook_ran "pre-deploy", output, **hook_variables
      assert_match "docker tag dhh/app:123 dhh/app:latest", output
      assert_match "docker run --detach --restart unless-stopped --name app-web-123", output
      assert_match "docker container ls --all --filter name=^app-web-version-to-rollback$ --quiet | xargs docker stop", output, "Should stop the container that was previously running"
-      assert_hook_ran "post-deploy", output, **hook_variables, runtime: true
+      assert_hook_ran "post-deploy", output, **hook_variables, runtime: "0"
    end
  end

@@ -319,7 +280,7 @@ class CliMainTest < CliTestCase
      .with(:docker, :container, :ls, "--all", "--filter", "name=^app-web-123$", "--quiet", raise_on_non_zero_exit: false)
      .returns("").at_least_once
    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
-      .with(:sh, "-c", "'docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting --filter ancestor=$(docker image ls --filter reference=dhh/app:latest --format '\\''{{.ID}}'\\'') ; docker ps --latest --format '\\''{{.Names}}'\\'' --filter label=service=app --filter label=role=web --filter status=running --filter status=restarting'", "|", :head, "-1", "|", "while read line; do echo ${line#app-web-}; done", raise_on_non_zero_exit: false)
+      .with(:docker, :ps, "--filter", "label=service=app", "--filter", "label=role=web", "--filter", "status=running", "--filter", "status=restarting", "--latest", "--format", "\"{{.Names}}\"", "|", "while read line; do echo ${line#app-web-}; done", raise_on_non_zero_exit: false)
      .returns("").at_least_once
    SSHKit::Backend::Abstract.any_instance.expects(:capture_with_info)
      .with(:docker, :container, :ls, "--all", "--filter", "name=^app-web-123$", "--quiet", "|", :xargs, :docker, :inspect, "--format", "'{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}'")
@@ -395,6 +356,19 @@ class CliMainTest < CliTestCase
    end
  end

+  test "config with aliases" do
+    run_command("config", config_file: "deploy_with_aliases").tap do |output|
+      config = YAML.load(output)
+
+      assert_equal [ "web", "web_tokyo", "workers", "workers_tokyo" ], config[:roles]
+      assert_equal [ "1.1.1.1", "1.1.1.2", "1.1.1.3", "1.1.1.4" ], config[:hosts]
+      assert_equal "999", config[:version]
+      assert_equal "registry.digitalocean.com/dhh/app", config[:repository]
+      assert_equal "registry.digitalocean.com/dhh/app:999", config[:absolute_image]
+      assert_equal "app-999", config[:service_with_version]
+    end
+  end
+
  test "init" do
    Pathname.any_instance.expects(:exist?).returns(false).times(3)
    Pathname.any_instance.stubs(:mkpath)
@@ -447,10 +421,10 @@ class CliMainTest < CliTestCase
  end

  test "envify" do
-    with_test_dotenv(".env.erb": "HELLO=<%= 'world' %>") do
-      run_command("envify")
-      assert_equal("HELLO=world", File.read(".env"))
-    end
+    File.expects(:read).with(".env.erb").returns("HELLO=<%= 'world' %>")
+    File.expects(:write).with(".env", "HELLO=world", perm: 0600)
+
+    run_command("envify")
  end

  test "envify with blank line trimming" do
@@ -461,21 +435,20 @@ class CliMainTest < CliTestCase
      <% end  -%>
    EOF

-    with_test_dotenv(".env.erb": file) do
-      run_command("envify")
-      assert_equal("HELLO=world\nKEY=value\n", File.read(".env"))
-    end
+    File.expects(:read).with(".env.erb").returns(file.strip)
+    File.expects(:write).with(".env", "HELLO=world\nKEY=value\n", perm: 0600)
+
+    run_command("envify")
  end

  test "envify with destination" do
-    with_test_dotenv(".env.world.erb": "HELLO=<%= 'world' %>") do
-      run_command("envify", "-d", "world", config_file: "deploy_for_dest")
-      assert_equal "HELLO=world", File.read(".env.world")
-    end
+    File.expects(:read).with(".env.world.erb").returns("HELLO=<%= 'world' %>")
+    File.expects(:write).with(".env.world", "HELLO=world", perm: 0600)
+
+    run_command("envify", "-d", "world", config_file: "deploy_for_dest")
  end

  test "envify with skip_push" do
-    Pathname.any_instance.expects(:exist?).returns(true).times(1)
    File.expects(:read).with(".env.erb").returns("HELLO=<%= 'world' %>")
    File.expects(:write).with(".env", "HELLO=world", perm: 0600)

@@ -483,13 +456,6 @@ class CliMainTest < CliTestCase
    run_command("envify", "--skip-push")
  end

-  test "envify with clean env" do
-    with_test_dotenv(".env": "HELLO=already", ".env.erb": "HELLO=<%= ENV.fetch 'HELLO', 'never' %>") do
-      run_command("envify", "--skip-push")
-      assert_equal "HELLO=never", File.read(".env")
-    end
-  end
-
  test "remove with confirmation" do
    run_command("remove", "-y", config_file: "deploy_with_accessories").tap do |output|
      assert_match /docker container stop traefik/, output
@@ -514,74 +480,13 @@ class CliMainTest < CliTestCase
    end
  end

-  test "docs" do
-    run_command("docs").tap do |output|
-      assert_match "# Kamal Configuration", output
-    end
-  end
-
-  test "docs subsection" do
-    run_command("docs", "accessory").tap do |output|
-      assert_match "# Accessories", output
-    end
-  end
-
-  test "docs unknown" do
-    run_command("docs", "foo").tap do |output|
-      assert_match "No documentation found for foo", output
-    end
-  end
-
  test "version" do
    version = stdouted { Kamal::Cli::Main.new.version }
    assert_equal Kamal::VERSION, version
  end

-  test "downgrade" do
-    invoke_options = { "config_file" => "test/fixtures/deploy_with_accessories.yml", "skip_hooks" => false, "confirmed" => true, "rolling" => false }
-    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:traefik:downgrade", [], invoke_options)
-    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:accessory:downgrade", [ "all" ], invoke_options)
-
-    run_command("downgrade", "-y", config_file: "deploy_with_accessories").tap do |output|
-      assert_match "Downgrading all hosts...", output
-      assert_match "Downgraded all hosts", output
-    end
-  end
-
-  test "downgrade rolling" do
-    invoke_options = { "config_file" => "test/fixtures/deploy_with_accessories.yml", "skip_hooks" => false, "confirmed" => true, "rolling" => false }
-    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:traefik:downgrade", [], invoke_options).times(4)
-    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:accessory:downgrade", [ "all" ], invoke_options).times(3)
-
-    run_command("downgrade", "--rolling", "-y", config_file: "deploy_with_accessories").tap do |output|
-      assert_match "Downgrading 1.1.1.1...", output
-      assert_match "Downgraded 1.1.1.1", output
-      assert_match "Downgrading 1.1.1.2...", output
-      assert_match "Downgraded 1.1.1.2", output
-      assert_match "Downgrading 1.1.1.3...", output
-      assert_match "Downgraded 1.1.1.3", output
-      assert_match "Downgrading 1.1.1.4...", output
-      assert_match "Downgraded 1.1.1.4", output
-    end
-  end
-
  private
    def run_command(*command, config_file: "deploy_simple")
      stdouted { Kamal::Cli::Main.start([ *command, "-c", "test/fixtures/#{config_file}.yml" ]) }
    end
-
-    def with_test_dotenv(**files)
-      Dir.mktmpdir do |dir|
-        fixtures_dup = File.join(dir, "test")
-        FileUtils.mkdir_p(fixtures_dup)
-        FileUtils.cp_r("test/fixtures/", fixtures_dup)
-
-        Dir.chdir(dir) do
-          files.each do |filename, contents|
-            File.binwrite(filename.to_s, contents)
-          end
-          yield
-        end
-      end
-    end
 end
--- a/Show More
+++ b/Show More