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moby--moby/distribution/push.go
Aaron Lehmann 8f26fe4f59 Push/pull errors improvement and cleanup
Several improvements to error handling:

- Introduce ImageConfigPullError type, wrapping errors related to
  downloading the image configuration blob in schema2. This allows for a
  more descriptive error message to be seen by the end user.

- Change some logrus.Debugf calls that display errors to logrus.Errorf.
  Add log lines in the push/pull fallback cases to make sure the errors
  leading to the fallback are shown.

- Move error-related types and functions which are only used by the
  distribution package out of the registry package.

Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
2016-02-11 16:28:56 -08:00

204 lines
6.7 KiB
Go

package distribution
import (
"bufio"
"compress/gzip"
"fmt"
"io"
"github.com/Sirupsen/logrus"
"github.com/docker/docker/distribution/metadata"
"github.com/docker/docker/distribution/xfer"
"github.com/docker/docker/image"
"github.com/docker/docker/layer"
"github.com/docker/docker/pkg/progress"
"github.com/docker/docker/reference"
"github.com/docker/docker/registry"
"github.com/docker/engine-api/types"
"github.com/docker/libtrust"
"golang.org/x/net/context"
)
// ImagePushConfig stores push configuration.
type ImagePushConfig struct {
// MetaHeaders store HTTP headers with metadata about the image
MetaHeaders map[string][]string
// AuthConfig holds authentication credentials for authenticating with
// the registry.
AuthConfig *types.AuthConfig
// ProgressOutput is the interface for showing the status of the push
// operation.
ProgressOutput progress.Output
// RegistryService is the registry service to use for TLS configuration
// and endpoint lookup.
RegistryService *registry.Service
// ImageEventLogger notifies events for a given image
ImageEventLogger func(id, name, action string)
// MetadataStore is the storage backend for distribution-specific
// metadata.
MetadataStore metadata.Store
// LayerStore manages layers.
LayerStore layer.Store
// ImageStore manages images.
ImageStore image.Store
// ReferenceStore manages tags.
ReferenceStore reference.Store
// TrustKey is the private key for legacy signatures. This is typically
// an ephemeral key, since these signatures are no longer verified.
TrustKey libtrust.PrivateKey
// UploadManager dispatches uploads.
UploadManager *xfer.LayerUploadManager
}
// 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 &v1Pusher{
v1IDService: metadata.NewV1IDService(imagePushConfig.MetadataStore),
ref: ref,
endpoint: endpoint,
repoInfo: repoInfo,
config: imagePushConfig,
}, nil
}
return nil, fmt.Errorf("unknown version %d for registry %s", endpoint.Version, endpoint.URL)
}
// Push initiates a push operation on the repository named localName.
// 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(repoInfo)
if err != nil {
return err
}
progress.Messagef(imagePushConfig.ProgressOutput, "", "The push refers to a repository [%s]", repoInfo.FullName())
associations := imagePushConfig.ReferenceStore.ReferencesByName(repoInfo)
if len(associations) == 0 {
return fmt.Errorf("Repository does not exist: %s", 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
)
for _, endpoint := range endpoints {
if confirmedV2 && endpoint.Version == registry.APIVersion1 {
logrus.Debugf("Skipping v1 endpoint %s because v2 registry was detected", endpoint.URL)
continue
}
logrus.Debugf("Trying to push %s to %s %s", repoInfo.FullName(), 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
err = fallbackErr.err
lastErr = err
logrus.Errorf("Attempting next endpoint for push after error: %v", err)
continue
}
}
logrus.Errorf("Not continuing with push after error: %v", err)
return err
}
imagePushConfig.ImageEventLogger(ref.String(), repoInfo.Name(), "push")
return nil
}
if lastErr == nil {
lastErr = fmt.Errorf("no endpoints found for %s", repoInfo.FullName())
}
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
}