Function serveLocalRegistry

envbuilder.go:1863–1909

Allows quick testing of layer caching using a local directory!

(ctx context.Context, logf log.Func, layerCacheDir string)

// Allows quick testing of layer caching using a local directory!
func serveLocalRegistry(ctx context.Context, logf log.Func, layerCacheDir string) (string, func(), error) {
	noop := func() {}
	if layerCacheDir == "" {
		return "", noop, nil
	}
	cfg := &configuration.Configuration{
		Storage: configuration.Storage{
			"filesystem": configuration.Parameters{
				"rootdirectory": layerCacheDir,
			},
		},
	}
	cfg.Log.Level = "error"

	// Spawn an in-memory registry to cache built layers...
	registry := handlers.NewApp(ctx, cfg)

	listener, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		return "", nil, fmt.Errorf("start listener for in-memory registry: %w", err)
	}
	tcpAddr, ok := listener.Addr().(*net.TCPAddr)
	if !ok {
		return "", noop, fmt.Errorf("listener addr was of wrong type: %T", listener.Addr())
	}
	srv := &http.Server{
		Handler: registry,
	}
	done := make(chan struct{})
	go func() {
		defer close(done)
		err := srv.Serve(listener)
		if err != nil && !errors.Is(err, http.ErrServerClosed) {
			logf(log.LevelError, "Failed to serve registry: %s", err.Error())
		}
	}()
	var closeOnce sync.Once
	closer := func() {
		closeOnce.Do(func() {
			_ = srv.Close()
			_ = listener.Close()
			<-done
		})
	}
	addr := fmt.Sprintf("localhost:%d/local/cache", tcpAddr.Port)
	return addr, closer, nil
}