Rip out context_hosts checks

The remote host is now encoded in the builder name so we don't need
to check it. We'll just do an inspect to confirm the builder exists.

lib/kamal/cli/build.rb

@@ -30,18 +30,9 @@ class Kamal::Cli::Build < Kamal::Cli::Base
       say "Building with uncommitted changes:\n #{uncommitted_changes}", :yellow
     end
 
-    # 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
-        end
+        execute *KAMAL.builder.buildx_inspect
       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"
@@ -51,6 +42,9 @@ class Kamal::Cli::Build < Kamal::Cli::Base
         end
       end
 
+      # Get the command here to ensure the Dir.chdir doesn't interfere with it
+      push = KAMAL.builder.push
+
       KAMAL.with_verbosity(:debug) do
         Dir.chdir(KAMAL.config.builder.build_directory) { execute *push }
       end

lib/kamal/commands/builder.rb

@@ -1,8 +1,7 @@
 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
+  delegate :create, :remove, :push, :clean, :pull, :info, :buildx_inspect, :validate_image, :first_mirror, to: :target
 
   include Clone
 

lib/kamal/commands/builder/base.rb

@@ -1,4 +1,3 @@
-
 class Kamal::Commands::Builder::Base < Kamal::Commands::Base
   class BuilderError < StandardError; end
 
@@ -14,10 +13,29 @@ class Kamal::Commands::Builder::Base < Kamal::Commands::Base
     docker :image, :rm, "--force", config.absolute_image
   end
 
+  def push
+    docker :buildx, :build,
+      "--push",
+      *platform_options,
+      "--builder", builder_name,
+      *build_options,
+      build_context
+  end
+
   def pull
     docker :pull, config.absolute_image
   end
 
+  def info
+    combine \
+      docker(:context, :ls),
+      docker(:buildx, :ls)
+  end
+
+  def buildx_inspect
+    docker :buildx, :inspect, builder_name
+  end
+
   def build_options
     [ *build_tags, *build_cache, *build_labels, *build_args, *build_secrets, *build_dockerfile, *build_target, *build_ssh ]
   end
@@ -35,14 +53,6 @@ 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

lib/kamal/commands/builder/hybrid.rb

@@ -1,4 +1,4 @@
-class Kamal::Commands::Builder::Hybrid < Kamal::Commands::Builder::Base
+class Kamal::Commands::Builder::Hybrid < Kamal::Commands::Builder::Remote
   def create
     combine \
       create_local_buildx,
@@ -6,18 +6,9 @@ class Kamal::Commands::Builder::Hybrid < Kamal::Commands::Builder::Base
       append_remote_buildx
   end
 
-  def context_hosts
-    chain \
-      context_host(builder_name)
-  end
-
-  def config_context_hosts
-    [ remote_host ].compact
-  end
-
   private
     def builder_name
-      "kamal-hybrid-#{remote_host.gsub(/[^a-z0-9_-]/, "-")}-#{local_arch}-#{remote_arch}"
+      "kamal-hybrid-#{local_arch}-#{remote_arch}-#{remote_host.gsub(/[^a-z0-9_-]/, "-")}"
     end
 
     def create_local_buildx
@@ -28,7 +19,7 @@ class Kamal::Commands::Builder::Hybrid < Kamal::Commands::Builder::Base
       docker :buildx, :create, "--append", "--name", builder_name, builder_name, "--platform", "linux/#{remote_arch}"
     end
 
-    def platform_options
-      [ "--platform", "linux/#{local_arch},linux/#{remote_arch}" ]
+    def platform
+      "linux/#{local_arch},linux/#{remote_arch}"
     end
 end

lib/kamal/commands/builder/local.rb

@@ -7,25 +7,6 @@ class Kamal::Commands::Builder::Local < 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",
-      *platform_options,
-      "--builder", builder_name,
-      *build_options,
-      build_context
-  end
-
-  def context_hosts
-    docker :buildx, :inspect, builder_name, "> /dev/null"
-  end
-
   private
     def builder_name
       "kamal-local"

lib/kamal/commands/builder/remote.rb

@@ -26,18 +26,9 @@ class Kamal::Commands::Builder::Remote < Kamal::Commands::Builder::Base
       build_context
   end
 
-  def context_hosts
-    context_host(builder_name)
-  end
-
-  def config_context_hosts
-    [ remote_host ]
-  end
-
-
   private
     def builder_name
-      "kamal-remote-#{remote_host.gsub(/[^a-z0-9_-]/, "-")}-#{remote_arch}"
+      "kamal-remote-#{remote_arch}-#{remote_host.gsub(/[^a-z0-9_-]/, "-")}"
     end
 
     def create_remote_context
@@ -57,6 +48,10 @@ class Kamal::Commands::Builder::Remote < Kamal::Commands::Builder::Base
     end
 
     def platform_options
-      [ "--platform", "linux/#{remote_arch}" ]
+      [ "--platform", platform ]
+    end
+
+    def platform
+      "linux/#{remote_arch}"
     end
 end