distribution/registry/storage/blobserver.go
Stephen J Day 9c88801a12
context: remove definition of Context
Back in the before time, the best practices surrounding usage of Context
weren't quite worked out. We defined our own type to make usage easier.
As this packaged was used elsewhere, it make it more and more
challenging to integrate with the forked `Context` type. Now that it is
available in the standard library, we can just use that one directly.

To make usage more consistent, we now use `dcontext` when referring to
the distribution context package.

Signed-off-by: Stephen J Day <stephen.day@docker.com>
2017-08-11 15:53:31 -07:00

78 lines
2.1 KiB
Go

package storage
import (
"context"
"fmt"
"net/http"
"time"
"github.com/docker/distribution"
"github.com/docker/distribution/registry/storage/driver"
"github.com/opencontainers/go-digest"
)
// TODO(stevvooe): This should configurable in the future.
const blobCacheControlMaxAge = 365 * 24 * time.Hour
// blobServer simply serves blobs from a driver instance using a path function
// to identify paths and a descriptor service to fill in metadata.
type blobServer struct {
driver driver.StorageDriver
statter distribution.BlobStatter
pathFn func(dgst digest.Digest) (string, error)
redirect bool // allows disabling URLFor redirects
}
func (bs *blobServer) ServeBlob(ctx context.Context, w http.ResponseWriter, r *http.Request, dgst digest.Digest) error {
desc, err := bs.statter.Stat(ctx, dgst)
if err != nil {
return err
}
path, err := bs.pathFn(desc.Digest)
if err != nil {
return err
}
if bs.redirect {
redirectURL, err := bs.driver.URLFor(ctx, path, map[string]interface{}{"method": r.Method})
switch err.(type) {
case nil:
// Redirect to storage URL.
http.Redirect(w, r, redirectURL, http.StatusTemporaryRedirect)
return err
case driver.ErrUnsupportedMethod:
// Fallback to serving the content directly.
default:
// Some unexpected error.
return err
}
}
br, err := newFileReader(ctx, bs.driver, path, desc.Size)
if err != nil {
return err
}
defer br.Close()
w.Header().Set("ETag", fmt.Sprintf(`"%s"`, desc.Digest)) // If-None-Match handled by ServeContent
w.Header().Set("Cache-Control", fmt.Sprintf("max-age=%.f", blobCacheControlMaxAge.Seconds()))
if w.Header().Get("Docker-Content-Digest") == "" {
w.Header().Set("Docker-Content-Digest", desc.Digest.String())
}
if w.Header().Get("Content-Type") == "" {
// Set the content type if not already set.
w.Header().Set("Content-Type", desc.MediaType)
}
if w.Header().Get("Content-Length") == "" {
// Set the content length if not already set.
w.Header().Set("Content-Length", fmt.Sprint(desc.Size))
}
http.ServeContent(w, r, desc.Digest.String(), time.Time{}, br)
return nil
}