Adds support for Docker Build Cloud

lib/kamal/commands/builder.rb

@@ -2,7 +2,7 @@ require "active_support/core_ext/string/filters"
 
 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 @@ class Kamal::Commands::Builder < Kamal::Commands::Base
       else
         remote
       end
+    elsif cloud?
+      cloud
     else
       local
     end
@@ -34,6 +36,10 @@ class Kamal::Commands::Builder < Kamal::Commands::Base
     @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 +1,22 @@
+class Kamal::Commands::Builder::Cloud < Kamal::Commands::Builder::Base
+  # Expects `driver` to be of format "cloud docker-org-name/builder-name"
+
+  def create
+    docker :buildx, :create, "--driver", driver
+  end
+
+  def remove
+    docker :buildx, :rm, builder_name
+  end
+
+  private
+    def builder_name
+      driver.gsub(/[ \/]/, "-")
+    end
+
+    def inspect_buildx
+      pipe \
+        docker(:buildx, :inspect, builder_name),
+        grep("-q", "Endpoint:.*cloud://.*")
+    end
+end

lib/kamal/configuration/builder.rb

@@ -53,6 +53,10 @@ class Kamal::Configuration::Builder
     !local_disabled? && (arches.empty? || local_arches.any?)
   end
 
+  def cloud?
+    driver.start_with? "cloud"
+  end
+
   def cached?
     !!builder_config["cache"]
   end

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
   #