Simplify builders config

lib/kamal/cli/build.rb

@@ -30,18 +30,9 @@ def push
       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 @@ def push
         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
@@ -72,7 +66,7 @@ def pull
 
   desc "create", "Create a build setup"
   def create
-    if (remote_host = KAMAL.config.builder.remote_host)
+    if (remote_host = KAMAL.config.builder.remote)
       connect_to_remote_host(remote_host)
     end
 

lib/kamal/cli/templates/deploy.yml

@@ -18,6 +18,10 @@ registry:
   password:
     - KAMAL_REGISTRY_PASSWORD
 
+# Configure builder setup.
+builder:
+  arch: amd64
+
 # Inject ENV variables into containers (secrets come from .env).
 # Remember to run `kamal env push` after making changes!
 # env:
@@ -30,16 +34,6 @@ registry:
 # ssh:
 #   user: app
 
-# Configure builder setup.
-# builder:
-#   args:
-#     RUBY_VERSION: 3.2.0
-#   secrets:
-#     - GITHUB_TOKEN
-#   remote:
-#     arch: amd64
-#     host: ssh://app@192.168.0.1
-
 # Use accessory services (secrets come from .env).
 # accessories:
 #   db:

lib/kamal/commands/builder.rb

@@ -1,8 +1,8 @@
 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
+  delegate :local?, :remote?, to: "config.builder"
 
   include Clone
 
@@ -11,43 +11,27 @@ def name
   end
 
   def target
-    if config.builder.multiarch?
-      if config.builder.remote?
-        if config.builder.local?
-          multiarch_remote
-        else
-          native_remote
-        end
+    if remote?
+      if local?
+        hybrid
       else
-        multiarch
+        remote
       end
     else
-      if config.builder.cached?
-        native_cached
-      else
-        native
-      end
+      local
     end
   end
 
-  def native
-    @native ||= Kamal::Commands::Builder::Native.new(config)
-  end
-
-  def native_cached
-    @native ||= Kamal::Commands::Builder::Native::Cached.new(config)
-  end
-
-  def native_remote
-    @native ||= Kamal::Commands::Builder::Native::Remote.new(config)
+  def remote
+    @remote ||= Kamal::Commands::Builder::Remote.new(config)
   end
 
-  def multiarch
-    @multiarch ||= Kamal::Commands::Builder::Multiarch.new(config)
+  def local
+    @local ||= Kamal::Commands::Builder::Local.new(config)
   end
 
-  def multiarch_remote
-    @multiarch_remote ||= Kamal::Commands::Builder::Multiarch::Remote.new(config)
+  def hybrid
+    @hybrid ||= Kamal::Commands::Builder::Hybrid.new(config)
   end
 
 

lib/kamal/commands/builder/base.rb

@@ -1,20 +1,41 @@
-
 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, :target, :arches, :local_arches, :remote_arches, :remote,
+    :cache_from, :cache_to, :ssh, :driver, :docker_driver?,
+    to: :builder_config
 
   def clean
     docker :image, :rm, "--force", config.absolute_image
   end
 
+  def push
+    docker :buildx, :build,
+      "--push",
+      *platform_options(arches),
+      *([ "--builder", builder_name ] unless docker_driver?),
+      *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 unless docker_driver?
+  end
+
   def build_options
     [ *build_tags, *build_cache, *build_labels, *build_args, *build_secrets, *build_dockerfile, *build_target, *build_ssh ]
   end
@@ -32,14 +53,6 @@ def validate_image
       )
   end
 
-  def context_hosts
-    :true
-  end
-
-  def config_context_hosts
-    []
-  end
-
   def first_mirror
     docker(:info, "--format '{{index .RegistryConfig.Mirrors 0}}'")
   end
@@ -91,4 +104,8 @@ def builder_config
     def context_host(builder_name)
       docker :context, :inspect, builder_name, "--format", ENDPOINT_DOCKER_HOST_INSPECT
     end
+
+    def platform_options(arches)
+      argumentize "--platform", arches.map { |arch| "linux/#{arch}" }.join(",") if arches.any?
+    end
 end

lib/kamal/commands/builder/hybrid.rb

@@ -0,0 +1,21 @@
+class Kamal::Commands::Builder::Hybrid < Kamal::Commands::Builder::Remote
+  def create
+    combine \
+      create_local_buildx,
+      create_remote_context,
+      append_remote_buildx
+  end
+
+  private
+    def builder_name
+      "kamal-hybrid-#{driver}-#{remote.gsub(/[^a-z0-9_-]/, "-")}"
+    end
+
+    def create_local_buildx
+      docker :buildx, :create, *platform_options(local_arches), "--name", builder_name, "--driver=#{driver}"
+    end
+
+    def append_remote_buildx
+      docker :buildx, :create, *platform_options(remote_arches), "--append", "--name", builder_name, builder_name
+    end
+end

lib/kamal/commands/builder/local.rb

@@ -0,0 +1,14 @@
+class Kamal::Commands::Builder::Local < Kamal::Commands::Builder::Base
+  def create
+    docker :buildx, :create, "--name", builder_name, "--driver=#{driver}" unless docker_driver?
+  end
+
+  def remove
+    docker :buildx, :rm, builder_name unless docker_driver?
+  end
+
+  private
+    def builder_name
+      "kamal-local-#{driver}"
+    end
+end