Rename to Kamal

lib/kamal/commands/builder/multiarch.rb

@@ -0,0 +1,29 @@
+class Kamal::Commands::Builder::Multiarch < Kamal::Commands::Builder::Base
+  def create
+    docker :buildx, :create, "--use", "--name", builder_name
+  end
+
+  def remove
+    docker :buildx, :rm, builder_name
+  end
+
+  def push
+    docker :buildx, :build,
+      "--push",
+      "--platform", "linux/amd64,linux/arm64",
+      "--builder", builder_name,
+      *build_options,
+      build_context
+  end
+
+  def info
+    combine \
+      docker(:context, :ls),
+      docker(:buildx, :ls)
+  end
+
+  private
+    def builder_name
+      "kamal-#{config.service}-multiarch"
+    end
+end