WIP

lib/kamal/cli/app.rb

@@ -20,6 +20,9 @@ class Kamal::Cli::App < Kamal::Cli::Base
               auditor = KAMAL.auditor(role: role)
               role_config = KAMAL.config.role(role)
 
+              execute *app.extract_assets if role_config.assets?
+
+
               if capture_with_info(*app.container_id_for_version(version), raise_on_non_zero_exit: false).present?
                 tmp_version = "#{version}_replaced_#{SecureRandom.hex(8)}"
                 info "Renaming container #{version} to #{tmp_version} as already deployed on #{host}"
@@ -27,13 +30,14 @@ class Kamal::Cli::App < Kamal::Cli::Base
                 execute *app.rename_container(version: version, new_version: tmp_version)
               end
 
-              execute *auditor.record("Booted app version #{version}"), verbosity: :debug
-
               old_version = capture_with_info(*app.current_running_version, raise_on_non_zero_exit: false).strip
+              original_old_version = old_version.gsub(/_replaced_[a-f0-9]{16}$/, "")
 
-              if role_config.uses_cord?
-                execute *app.tie_cord(role_config.cord_host_file)
-              end
+              execute *app.sync_asset_volumes(old_version: original_old_version) if role_config.assets?
+
+              execute *app.tie_cord(role_config.cord_host_file) if role_config.uses_cord?
+
+              execute *auditor.record("Booted app version #{version}"), verbosity: :debug
 
               execute *app.run(hostname: "#{host}-#{SecureRandom.hex(6)}")
 
@@ -47,7 +51,10 @@ class Kamal::Cli::App < Kamal::Cli::Base
                     Kamal::Utils::HealthcheckPoller.wait_for_unhealthy(pause_after_ready: true) { capture_with_info(*app.status(version: old_version)) }
                   end
                 end
+
                 execute *app.stop(version: old_version), raise_on_non_zero_exit: false
+
+                execute *app.cleanup_assets if role_config.assets?
               end
             end
           end

lib/kamal/commands/app.rb

@@ -20,6 +20,7 @@ class Kamal::Commands::App < Kamal::Commands::Base
       *role_config.health_check_args,
       *config.logging_args,
       *config.volume_args,
+      *role_config.asset_volume_args,
       *role_config.label_args,
       *role_config.option_args,
       config.absolute_image,
@@ -105,7 +106,7 @@ class Kamal::Commands::App < Kamal::Commands::Base
   def list_versions(*docker_args, statuses: nil)
     pipe \
       docker(:ps, *filter_args(statuses: statuses), *docker_args, "--format", '"{{.Names}}"'),
-      %(while read line; do echo ${line##{role_config.full_name}-}; done) # Extract SHA from "service-role-dest-SHA"
+      %(while read line; do echo ${line##{role_config.container_prefix}-}; done) # Extract SHA from "service-role-dest-SHA"
   end
 
   def list_containers
@@ -153,7 +154,7 @@ class Kamal::Commands::App < Kamal::Commands::Base
   def cord(version:)
     pipe \
       docker(:inspect, "-f '{{ range .Mounts }}{{ .Source }} {{ .Destination }} {{ end }}'", container_name(version)),
-      [:awk, "'$2 == \"#{role_config.cord_container_directory}\" {print $1}'"]
+      [:awk, "'$2 == \"#{role_config.cord_volume.container_path}\" {print $1}'"]
   end
 
   def tie_cord(cord)
@@ -164,9 +165,43 @@ class Kamal::Commands::App < Kamal::Commands::Base
     remove_directory(cord)
   end
 
+  def extract_assets
+    asset_container = "#{role_config.container_prefix}-assets"
+
+    combine \
+      make_directory(role_config.asset_extracted_path),
+      [*docker(:stop, "-t 1", asset_container, "2> /dev/null"), "|| true"],
+      docker(:run, "--name", asset_container, "--detach", "--rm", config.latest_image, "sleep infinity"),
+      docker(:cp, "-L", "#{asset_container}:#{role_config.asset_path}/.", role_config.asset_extracted_path),
+      docker(:stop, "-t 1", asset_container),
+      by: "&&"
+  end
+
+  def sync_asset_volumes(old_version: nil)
+    new_extracted_path, new_volume_path = role_config.asset_extracted_path(config.version), role_config.asset_volume.host_path
+    if old_version.present?
+      old_extracted_path, old_volume_path = role_config.asset_extracted_path(old_version), role_config.asset_volume(old_version).host_path
+    end
+
+    commands = [make_directory(new_volume_path), copy_contents(new_extracted_path, new_volume_path)]
+
+    if old_version.present?
+      commands << copy_contents(new_extracted_path, old_volume_path)
+      commands << copy_contents(old_extracted_path, new_volume_path)
+    end
+
+    chain *commands
+  end
+
+  def cleanup_assets
+    chain \
+      find_and_remove_older_siblings(role_config.asset_extracted_path),
+      find_and_remove_older_siblings(role_config.asset_volume_path)
+  end
+
   private
     def container_name(version = nil)
-      [ role_config.full_name, version || config.version ].compact.join("-")
+      [ role_config.container_prefix, version || config.version ].compact.join("-")
     end
 
     def filter_args(statuses: nil)
@@ -186,4 +221,19 @@ class Kamal::Commands::App < Kamal::Commands::Base
         end
       end
     end
+
+    def find_and_remove_older_siblings(path)
+      [
+        :find,
+        Pathname.new(path).dirname,
+        "-maxdepth 1",
+        "-name", "'#{role_config.container_prefix}-*'",
+        "!", "-name", Pathname.new(path).basename,
+        "-exec rm -rf \"{}\" +"
+      ]
+    end
+
+    def copy_contents(source, destination)
+      [ :cp, "-rn", "#{source}/*", destination ]
+    end
 end

lib/kamal/configuration.rb

@@ -211,6 +211,10 @@ class Kamal::Configuration
     @run_id ||= SecureRandom.hex(16)
   end
 
+  def asset_path
+    raw_config.asset_path
+  end
+
   private
     # Will raise ArgumentError if any required config keys are missing
     def ensure_required_keys_present

lib/kamal/configuration/role.rb

@@ -48,11 +48,15 @@ class Kamal::Configuration::Role
     argumentize "--env-file", host_env_file_path
   end
 
+  def asset_volume_args
+    asset_volume&.docker_args
+  end
+
   def health_check_args(cord: true)
     if health_check_cmd.present?
       if cord && uses_cord?
         optionize({ "health-cmd" => health_check_cmd_with_cord, "health-interval" => health_check_interval })
-          .concat(["--volume", "#{cord_host_directory}:#{cord_container_directory}"])
+          .concat(cord_volume.docker_args)
       else
         optionize({ "health-cmd" => health_check_cmd, "health-interval" => health_check_interval })
       end
@@ -74,15 +78,23 @@ class Kamal::Configuration::Role
   end
 
   def uses_cord?
-    running_traefik? && cord_container_directory.present? && health_check_cmd.present?
+    running_traefik? && cord_volume && health_check_cmd.present?
   end
 
   def cord_host_directory
-    File.join config.run_directory_as_docker_volume, "cords", [full_name, config.run_id].join("-")
+    File.join config.run_directory_as_docker_volume, "cords", [container_prefix, config.run_id].join("-")
+  end
+
+  def cord_volume
+    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
+    end
   end
 
   def cord_host_file
-    File.join cord_host_directory, CORD_FILE
+    File.join cord_volume.host_path, CORD_FILE
   end
 
   def cord_container_directory
@@ -90,7 +102,7 @@ class Kamal::Configuration::Role
   end
 
   def cord_container_file
-    File.join cord_container_directory, CORD_FILE
+    File.join cord_volume.container_path, CORD_FILE
   end
 
 
@@ -110,10 +122,37 @@ class Kamal::Configuration::Role
     name.web? || specializations["traefik"]
   end
 
-  def full_name
+  def container_name(version = nil)
+    [ container_prefix, version || config.version ].compact.join("-")
+  end
+
+  def container_prefix
     [ config.service, name, config.destination ].compact.join("-")
   end
 
+  def asset_path
+    specializations["asset_path"] || config.asset_path
+  end
+
+  def assets?
+    asset_path.present? && running_traefik?
+  end
+
+  def asset_volume(version = nil)
+    if assets?
+      Kamal::Configuration::Volume.new \
+        host_path: asset_volume_path(version), container_path: asset_path
+    end
+  end
+
+  def asset_extracted_path(version = nil)
+    File.join config.run_directory, "assets", "extracted", container_name(version)
+  end
+
+  def asset_volume_path(version = nil)
+    File.join config.run_directory, "assets", "volumes", container_name(version)
+  end
+
   private
     attr_accessor :config
 

lib/kamal/configuration/volume.rb

@@ -0,0 +1,22 @@
+class Kamal::Configuration::Volume
+  attr_reader :host_path, :container_path
+  delegate :argumentize, to: Kamal::Utils
+
+  def initialize(host_path:, container_path:)
+    @host_path = host_path
+    @container_path = container_path
+  end
+
+  def docker_args
+    argumentize "--volume", "#{host_path_for_docker_volume}:#{container_path}"
+  end
+
+  private
+    def host_path_for_docker_volume
+      if Pathname.new(host_path).absolute?
+        host_path
+      else
+        File.join "$(pwd)", host_path
+      end
+    end
+end

test/configuration/role_test.rb

@@ -180,16 +180,15 @@ class ConfigurationRoleTest < ActiveSupport::TestCase
     assert !@config_with_roles.role(:workers).uses_cord?
   end
 
-  test "cord host directory" do
-    assert_match %r{\$\(pwd\)/.kamal/cords/app-web-[0-9a-f]{32}}, @config_with_roles.role(:web).cord_host_directory
-  end
-
   test "cord host file" do
-    assert_match %r{\$\(pwd\)/.kamal/cords/app-web-[0-9a-f]{32}/cord}, @config_with_roles.role(:web).cord_host_file
+    assert_match %r{.kamal/cords/app-web-[0-9a-f]{32}/cord}, @config_with_roles.role(:web).cord_host_file
   end
 
-  test "cord container directory" do
-    assert_equal "/tmp/kamal-cord", @config_with_roles.role(:web).cord_container_directory
+  test "cord volume" do
+    assert_equal "/tmp/kamal-cord", @config_with_roles.role(:web).cord_volume.container_path
+    assert_match %r{.kamal/cords/app-web-[0-9a-f]{32}}, @config_with_roles.role(:web).cord_volume.host_path
+    assert_equal "--volume", @config_with_roles.role(:web).cord_volume.docker_args[0]
+    assert_match %r{\$\(pwd\)/.kamal/cords/app-web-[0-9a-f]{32}:/tmp/kamal-cord}, @config_with_roles.role(:web).cord_volume.docker_args[1]
   end
 
   test "cord container file" do

test/integration/docker/deployer/app/Dockerfile

@@ -4,4 +4,5 @@ COPY default.conf /etc/nginx/conf.d/default.conf
 
 ARG COMMIT_SHA
 RUN echo $COMMIT_SHA > /usr/share/nginx/html/version
+RUN mkdir -p /usr/share/nginx/html/versions && echo "version" > /usr/share/nginx/html/versions/$COMMIT_SHA
 

test/integration/docker/deployer/app/config/deploy.yml

@@ -8,6 +8,7 @@ env:
     CLEAR_TOKEN: '4321'
   secret:
     - SECRET_TOKEN
+asset_path: /usr/share/nginx/html/versions
 
 registry:
   server: registry:4443

test/integration/main_test.rb

@@ -20,6 +20,8 @@ class MainTest < IntegrationTest
     assert_app_is_up version: second_version
     assert_hooks_ran "pre-connect", "pre-build", "pre-deploy", "post-deploy"
 
+    assert_accumulated_assets first_version, second_version
+
     kamal :rollback, first_version
     assert_hooks_ran "pre-connect", "pre-deploy", "post-deploy"
     assert_app_is_up version: first_version
@@ -69,4 +71,10 @@ class MainTest < IntegrationTest
     def assert_no_remote_env_file
       assert_equal "nofile", docker_compose("exec vm1 stat /root/.kamal/env/roles/app-web.env 2> /dev/null || echo nofile", capture: true)
     end
+
+    def assert_accumulated_assets(*versions)
+      versions.each do |version|
+        assert_equal "200", Net::HTTP.get_response(URI.parse("http://localhost:12345/versions/#{version}")).code
+      end
+    end
 end