package distribution // import "github.com/docker/docker/distribution" import ( "bufio" "compress/gzip" "context" "fmt" "io" "github.com/docker/distribution/reference" "github.com/docker/docker/distribution/metadata" "github.com/docker/docker/pkg/progress" "github.com/docker/docker/registry" "github.com/sirupsen/logrus" ) // Pusher is an interface that abstracts pushing for different API versions. type Pusher interface { // Push tries to push the image configured at the creation of Pusher. // Push returns an error if any, as well as a boolean that determines whether to retry Push on the next configured endpoint. // // TODO(tiborvass): have Push() take a reference to repository + tag, so that the pusher itself is repository-agnostic. Push(ctx context.Context) error } const compressionBufSize = 32768 // NewPusher creates a new Pusher interface that will push to either a v1 or v2 // registry. The endpoint argument contains a Version field that determines // whether a v1 or v2 pusher will be created. The other parameters are passed // through to the underlying pusher implementation for use during the actual // push operation. func NewPusher(ref reference.Named, endpoint registry.APIEndpoint, repoInfo *registry.RepositoryInfo, imagePushConfig *ImagePushConfig) (Pusher, error) { switch endpoint.Version { case registry.APIVersion2: return &v2Pusher{ v2MetadataService: metadata.NewV2MetadataService(imagePushConfig.MetadataStore), ref: ref, endpoint: endpoint, repoInfo: repoInfo, config: imagePushConfig, }, nil case registry.APIVersion1: return nil, fmt.Errorf("protocol version %d no longer supported. Please contact admins of registry %s", endpoint.Version, endpoint.URL) } return nil, fmt.Errorf("unknown version %d for registry %s", endpoint.Version, endpoint.URL) } // Push initiates a push operation on ref. // ref is the specific variant of the image to be pushed. // If no tag is provided, all tags will be pushed. func Push(ctx context.Context, ref reference.Named, imagePushConfig *ImagePushConfig) error { // FIXME: Allow to interrupt current push when new push of same image is done. // Resolve the Repository name from fqn to RepositoryInfo repoInfo, err := imagePushConfig.RegistryService.ResolveRepository(ref) if err != nil { return err } endpoints, err := imagePushConfig.RegistryService.LookupPushEndpoints(reference.Domain(repoInfo.Name)) if err != nil { return err } progress.Messagef(imagePushConfig.ProgressOutput, "", "The push refers to repository [%s]", repoInfo.Name.Name()) associations := imagePushConfig.ReferenceStore.ReferencesByName(repoInfo.Name) if len(associations) == 0 { return fmt.Errorf("An image does not exist locally with the tag: %s", reference.FamiliarName(repoInfo.Name)) } var ( lastErr error // confirmedV2 is set to true if a push attempt managed to // confirm that it was talking to a v2 registry. This will // prevent fallback to the v1 protocol. confirmedV2 bool // confirmedTLSRegistries is a map indicating which registries // are known to be using TLS. There should never be a plaintext // retry for any of these. confirmedTLSRegistries = make(map[string]struct{}) ) for _, endpoint := range endpoints { if imagePushConfig.RequireSchema2 && endpoint.Version == registry.APIVersion1 { continue } if confirmedV2 && endpoint.Version == registry.APIVersion1 { logrus.Debugf("Skipping v1 endpoint %s because v2 registry was detected", endpoint.URL) continue } if endpoint.URL.Scheme != "https" { if _, confirmedTLS := confirmedTLSRegistries[endpoint.URL.Host]; confirmedTLS { logrus.Debugf("Skipping non-TLS endpoint %s for host/port that appears to use TLS", endpoint.URL) continue } } logrus.Debugf("Trying to push %s to %s %s", repoInfo.Name.Name(), endpoint.URL, endpoint.Version) pusher, err := NewPusher(ref, endpoint, repoInfo, imagePushConfig) if err != nil { lastErr = err continue } if err := pusher.Push(ctx); err != nil { // Was this push cancelled? If so, don't try to fall // back. select { case <-ctx.Done(): default: if fallbackErr, ok := err.(fallbackError); ok { confirmedV2 = confirmedV2 || fallbackErr.confirmedV2 if fallbackErr.transportOK && endpoint.URL.Scheme == "https" { confirmedTLSRegistries[endpoint.URL.Host] = struct{}{} } err = fallbackErr.err lastErr = err logrus.Infof("Attempting next endpoint for push after error: %v", err) continue } } logrus.Errorf("Not continuing with push after error: %v", err) return err } imagePushConfig.ImageEventLogger(reference.FamiliarString(ref), reference.FamiliarName(repoInfo.Name), "push") return nil } if lastErr == nil { lastErr = fmt.Errorf("no endpoints found for %s", repoInfo.Name.Name()) } return lastErr } // compress returns an io.ReadCloser which will supply a compressed version of // the provided Reader. The caller must close the ReadCloser after reading the // compressed data. // // Note that this function returns a reader instead of taking a writer as an // argument so that it can be used with httpBlobWriter's ReadFrom method. // Using httpBlobWriter's Write method would send a PATCH request for every // Write call. // // The second return value is a channel that gets closed when the goroutine // is finished. This allows the caller to make sure the goroutine finishes // before it releases any resources connected with the reader that was // passed in. func compress(in io.Reader) (io.ReadCloser, chan struct{}) { compressionDone := make(chan struct{}) pipeReader, pipeWriter := io.Pipe() // Use a bufio.Writer to avoid excessive chunking in HTTP request. bufWriter := bufio.NewWriterSize(pipeWriter, compressionBufSize) compressor := gzip.NewWriter(bufWriter) go func() { _, err := io.Copy(compressor, in) if err == nil { err = compressor.Close() } if err == nil { err = bufWriter.Flush() } if err != nil { pipeWriter.CloseWithError(err) } else { pipeWriter.Close() } close(compressionDone) }() return pipeReader, compressionDone }