Build from a git archive

Building directly from a checkout will pull in uncommitted files to or
more sneakily files that are git ignored, but not docker ignored.

To avoid this, we'll add an option to build from a git archive of HEAD
instead. Docker doesn't provide a way to build directly from a git
repo, so instead we create a tarball of the current HEAD with git
archive and pipe it into the build command.

When building from a git archive, we'll still display the warning about
uncommitted changes, but we won't add the `_uncommitted_...` suffix to
the container name as they won't be included in the build.

Perhaps this should be the default, but we'll leave that decision for
now.

test/commands/builder_test.rb

@@ -123,6 +123,34 @@ class CommandsBuilderTest < ActiveSupport::TestCase
     assert_equal "docker inspect -f '{{ .Config.Labels.service }}' dhh/app:123 | grep -x app || (echo \"Image dhh/app:123 is missing the 'service' label\" && exit 1)", new_builder_command.validate_image.join(" ")
   end
 
+  test "multiarch git archive build" do
+    builder = new_builder_command(builder: { "git_archive" => true })
+    assert_equal \
+      "git archive --format=tar HEAD | docker buildx build --push --platform linux/amd64,linux/arm64 --builder kamal-app-multiarch -t dhh/app:123 -t dhh/app:latest --label service=\"app\" --file Dockerfile -",
+      builder.push.join(" ")
+  end
+
+  test "native git archive build" do
+    builder = new_builder_command(builder: { "multiarch" => false, "git_archive" => true })
+    assert_equal \
+      "git archive --format=tar HEAD | docker build -t dhh/app:123 -t dhh/app:latest --label service=\"app\" --file Dockerfile - && docker push dhh/app:123 && docker push dhh/app:latest",
+      builder.push.join(" ")
+  end
+
+  test "cached git archive build" do
+    builder = new_builder_command(builder: { "multiarch" => false, "git_archive" => true, "cache" => { "type" => "gha" } })
+    assert_equal \
+      "git archive --format=tar HEAD | docker buildx build --push -t dhh/app:123 -t dhh/app:latest --cache-to type=gha --cache-from type=gha --label service=\"app\" --file Dockerfile -",
+      builder.push.join(" ")
+  end
+
+  test "remote git archive build" do
+    builder = new_builder_command(builder: { "remote" => { "arch" => "amd64" }, "git_archive" => true })
+    assert_equal \
+      "git archive --format=tar HEAD | docker buildx build --push --platform linux/amd64 --builder kamal-app-native-remote -t dhh/app:123 -t dhh/app:latest --label service=\"app\" --file Dockerfile -",
+      builder.push.join(" ")
+  end
+
   private
     def new_builder_command(additional_config = {})
       Kamal::Commands::Builder.new(Kamal::Configuration.new(@config.merge(additional_config), version: "123"))

test/configuration_test.rb

@@ -106,6 +106,16 @@ class ConfigurationTest < ActiveSupport::TestCase
     assert_match /^git-version_uncommitted_[0-9a-f]{16}$/, @config.version
   end
 
+  test "version from git archive uncommitted" do
+    ENV.delete("VERSION")
+
+    config = Kamal::Configuration.new(@deploy.tap { |c| c[:builder] = { "git_archive" => true } })
+
+    Kamal::Git.expects(:revision).returns("git-version")
+    Kamal::Git.expects(:uncommitted_changes).returns("M   file\n")
+    assert_equal "git-version", config.version
+  end
+
   test "version from env" do
     ENV["VERSION"] = "env-version"
     assert_equal "env-version", @config.version