Adds support for Docker Build Cloud

lib/kamal/commands/builder.rb

@@ -2,7 +2,7 @@
 
 class Kamal::Commands::Builder < Kamal::Commands::Base
   delegate :create, :remove, :push, :clean, :pull, :info, :inspect_builder, :validate_image, :first_mirror, to: :target
-  delegate :local?, :remote?, to: "config.builder"
+  delegate :local?, :remote?, :cloud?, to: "config.builder"
 
   include Clone
 
@@ -17,6 +17,8 @@ def target
       else
         remote
       end
+    elsif cloud?
+      cloud
     else
       local
     end
@@ -34,6 +36,10 @@ def hybrid
     @hybrid ||= Kamal::Commands::Builder::Hybrid.new(config)
   end
 
+  def cloud
+    @cloud ||= Kamal::Commands::Builder::Cloud.new(config)
+  end
+
 
   def ensure_local_dependencies_installed
     if name.native?

lib/kamal/commands/builder/cloud.rb

@@ -0,0 +1,8 @@
+class Kamal::Commands::Builder::Cloud < Kamal::Commands::Builder::Base
+  private
+    def builder_name
+      # Expected format: "cloud docker-org-name/builder-name"
+      docker_cloud_build_parts = driver.sub(/^cloud /, "").split("/")
+      "cloud-#{docker_cloud_build_parts[0]}-#{docker_cloud_build_parts[1]}"
+    end
+end

lib/kamal/configuration/builder.rb

@@ -53,6 +53,10 @@ def local?
     !local_disabled? && (arches.empty? || local_arches.any?)
   end
 
+  def cloud?
+    driver.start_with? "cloud"
+  end
+
   def cached?
     !!builder_config["cache"]
   end
@@ -137,7 +141,7 @@ def build_directory
   end
 
   def docker_driver?
-    driver == "docker"
+    driver == "docker" || driver == "cloud"
   end
 
   private

lib/kamal/configuration/docs/builder.yml

@@ -102,6 +102,9 @@ builder:
   #
   # The build driver to use, defaults to `docker-container`:
   driver: docker
+  #
+  # If you want to use Docker Build Cloud (https://www.docker.com/products/build-cloud/), you can set the driver to:
+  driver: cloud org-name/builder-name
 
   # Provenance
   #

test/commands/builder_test.rb

@@ -61,6 +61,14 @@ class CommandsBuilderTest < ActiveSupport::TestCase
       builder.push.join(" ")
   end
 
+  test "cloud builder" do
+    builder = new_builder_command(builder: { "arch" => [ "#{local_arch}" ], "driver" => "cloud docker-org-name/builder-name" })
+    assert_equal "cloud", builder.name
+    assert_equal \
+      "docker buildx build --push --platform linux/#{local_arch} --builder cloud-docker-org-name-builder-name -t dhh/app:123 -t dhh/app:latest --label service=\"app\" --file Dockerfile .",
+      builder.push.join(" ")
+  end
+
   test "build args" do
     builder = new_builder_command(builder: { "args" => { "a" => 1, "b" => 2 } })
     assert_equal \