Move multiarch remote builder to hybrid builder

Include the host name in the builder name, so we can have one builder
per host/arch across all kamal projects.

Inherit from the remote builder. The difference in the hybrid builder
is that we create a local buildx instance and append the remote context
to it.

lib/kamal/commands/builder.rb

@@ -17,7 +17,7 @@ class Kamal::Commands::Builder < Kamal::Commands::Base
     when !config.builder.multiarch? && config.builder.cached?
       local
     when config.builder.local? && config.builder.remote?
-      multiarch_remote
+      hybrid
     when config.builder.remote?
       remote
     else
@@ -33,8 +33,8 @@ class Kamal::Commands::Builder < Kamal::Commands::Base
     @local ||= Kamal::Commands::Builder::Local.new(config)
   end
 
-  def multiarch_remote
+  def hybrid
-    @multiarch_remote ||= Kamal::Commands::Builder::Multiarch::Remote.new(config)
+    @hybrid ||= Kamal::Commands::Builder::Hybrid.new(config)
   end
 
 

lib/kamal/commands/builder/hybrid.rb

@@ -0,0 +1,34 @@
+class Kamal::Commands::Builder::Hybrid < Kamal::Commands::Builder::Base
+  def create
+    combine \
+      create_local_buildx,
+      create_remote_context,
+      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}"
+    end
+
+    def create_local_buildx
+      docker :buildx, :create, "--name", builder_name, "--platform", "linux/#{local_arch}", "--driver=docker-container"
+    end
+
+    def append_remote_buildx
+      docker :buildx, :create, "--append", "--name", builder_name, builder_name, "--platform", "linux/#{remote_arch}"
+    end
+
+    def platform_options
+      [ "--platform", "linux/#{local_arch},linux/#{remote_arch}" ]
+    end
+end

lib/kamal/commands/builder/multiarch/remote.rb

@@ -1,84 +0,0 @@
-class Kamal::Commands::Builder::Multiarch::Remote < Kamal::Commands::Builder::Base
-  def create
-    combine \
-      create_contexts,
-      create_local_buildx,
-      append_remote_buildx
-  end
-
-  def remove
-    combine \
-      remove_contexts,
-      super
-  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
-    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
-      "kamal-#{config.service}-multiarch-remote"
-    end
-
-    def builder_name_with_arch(arch)
-      "#{builder_name}-#{arch}"
-    end
-
-    def create_local_buildx
-      docker :buildx, :create, "--name", builder_name, builder_name_with_arch(local_arch), "--platform", "linux/#{local_arch}"
-    end
-
-    def append_remote_buildx
-      docker :buildx, :create, "--append", "--name", builder_name, builder_name_with_arch(remote_arch), "--platform", "linux/#{remote_arch}"
-    end
-
-    def create_contexts
-      combine \
-        create_context(local_arch, local_host),
-        create_context(remote_arch, remote_host)
-    end
-
-    def create_context(arch, host)
-      docker :context, :create, builder_name_with_arch(arch), "--description", "'#{builder_name} #{arch} native host'", "--docker", "'host=#{host}'"
-    end
-
-    def remove_contexts
-      combine \
-        remove_context(local_arch),
-        remove_context(remote_arch)
-    end
-
-    def remove_context(arch)
-      docker :context, :rm, builder_name_with_arch(arch)
-    end
-
-    def platform_options
-      if local_arch
-        [ "--platform", "linux/#{local_arch}" ]
-      else
-        [ "--platform", "linux/amd64,linux/arm64" ]
-      end
-    end
-end

lib/kamal/commands/builder/remote.rb

@@ -1,13 +1,13 @@
 class Kamal::Commands::Builder::Remote < Kamal::Commands::Builder::Base
   def create
     chain \
-      create_context,
+      create_remote_context,
       create_buildx
   end
 
   def remove
     chain \
-      remove_context,
+      remove_remote_context,
       remove_buildx
   end
 
@@ -20,7 +20,7 @@ class Kamal::Commands::Builder::Remote < Kamal::Commands::Builder::Base
   def push
     docker :buildx, :build,
       "--push",
-    "--platform", platform,
+      *platform_options,
       "--builder", builder_name,
       *build_options,
       build_context
@@ -37,18 +37,14 @@ class Kamal::Commands::Builder::Remote < Kamal::Commands::Builder::Base
 
   private
     def builder_name
-      "kamal-remote-#{remote_arch}"
+      "kamal-remote-#{remote_host.gsub(/[^a-z0-9_-]/, "-")}-#{remote_arch}"
     end
 
-    def platform
+    def create_remote_context
-      "linux/#{remote_arch}"
-    end
-
-    def create_context
       docker :context, :create, builder_name, "--description", "'#{builder_name} host'", "--docker", "'host=#{remote_host}'"
     end
 
-    def remove_context
+    def remove_remote_context
       docker :context, :rm, builder_name
     end
 
@@ -59,4 +55,8 @@ class Kamal::Commands::Builder::Remote < Kamal::Commands::Builder::Base
     def remove_buildx
       docker :buildx, :rm, builder_name
     end
+
+    def platform_options
+      [ "--platform", "linux/#{remote_arch}" ]
+    end
 end