distribution/docs/garbagecollect.go
Richard Scothern 3d4b652b58 Update the gc documentation.
Signed-off-by: Richard Scothern <richard.scothern@gmail.com>
2016-03-30 16:57:21 -07:00

187 lines
5.3 KiB
Go

package registry
import (
"fmt"
"os"
"github.com/docker/distribution"
"github.com/docker/distribution/context"
"github.com/docker/distribution/digest"
"github.com/docker/distribution/manifest/schema1"
"github.com/docker/distribution/manifest/schema2"
"github.com/docker/distribution/reference"
"github.com/docker/distribution/registry/storage"
"github.com/docker/distribution/registry/storage/driver"
"github.com/docker/distribution/registry/storage/driver/factory"
"github.com/docker/libtrust"
"github.com/spf13/cobra"
)
func emit(format string, a ...interface{}) {
if dryRun {
fmt.Printf(format+"\n", a...)
}
}
func markAndSweep(ctx context.Context, storageDriver driver.StorageDriver, registry distribution.Namespace) error {
repositoryEnumerator, ok := registry.(distribution.RepositoryEnumerator)
if !ok {
return fmt.Errorf("unable to convert Namespace to RepositoryEnumerator")
}
// mark
markSet := make(map[digest.Digest]struct{})
err := repositoryEnumerator.Enumerate(ctx, func(repoName string) error {
emit(repoName)
var err error
named, err := reference.ParseNamed(repoName)
if err != nil {
return fmt.Errorf("failed to parse repo name %s: %v", repoName, err)
}
repository, err := registry.Repository(ctx, named)
if err != nil {
return fmt.Errorf("failed to construct repository: %v", err)
}
manifestService, err := repository.Manifests(ctx)
if err != nil {
return fmt.Errorf("failed to construct manifest service: %v", err)
}
manifestEnumerator, ok := manifestService.(distribution.ManifestEnumerator)
if !ok {
return fmt.Errorf("unable to convert ManifestService into ManifestEnumerator")
}
err = manifestEnumerator.Enumerate(ctx, func(dgst digest.Digest) error {
// Mark the manifest's blob
emit("%s: marking manifest %s ", repoName, dgst)
markSet[dgst] = struct{}{}
manifest, err := manifestService.Get(ctx, dgst)
if err != nil {
return fmt.Errorf("failed to retrieve manifest for digest %v: %v", dgst, err)
}
descriptors := manifest.References()
for _, descriptor := range descriptors {
markSet[descriptor.Digest] = struct{}{}
emit("%s: marking blob %s", repoName, descriptor.Digest)
}
switch manifest.(type) {
case *schema1.SignedManifest:
signaturesGetter, ok := manifestService.(distribution.SignaturesGetter)
if !ok {
return fmt.Errorf("unable to convert ManifestService into SignaturesGetter")
}
signatures, err := signaturesGetter.GetSignatures(ctx, dgst)
if err != nil {
return fmt.Errorf("failed to get signatures for signed manifest: %v", err)
}
for _, signatureDigest := range signatures {
emit("%s: marking signature %s", repoName, signatureDigest)
markSet[signatureDigest] = struct{}{}
}
break
case *schema2.DeserializedManifest:
config := manifest.(*schema2.DeserializedManifest).Config
emit("%s: marking configuration %s", repoName, config.Digest)
markSet[config.Digest] = struct{}{}
break
}
return nil
})
return err
})
if err != nil {
return fmt.Errorf("failed to mark: %v\n", err)
}
// sweep
blobService := registry.Blobs()
deleteSet := make(map[digest.Digest]struct{})
err = blobService.Enumerate(ctx, func(dgst digest.Digest) error {
// check if digest is in markSet. If not, delete it!
if _, ok := markSet[dgst]; !ok {
deleteSet[dgst] = struct{}{}
}
return nil
})
if err != nil {
return fmt.Errorf("error enumerating blobs: %v", err)
}
emit("\n%d blobs marked, %d blobs eligible for deletion", len(markSet), len(deleteSet))
// Construct vacuum
vacuum := storage.NewVacuum(ctx, storageDriver)
for dgst := range deleteSet {
emit("blob eligible for deletion: %s", dgst)
if dryRun {
continue
}
err = vacuum.RemoveBlob(string(dgst))
if err != nil {
return fmt.Errorf("failed to delete blob %s: %v\n", dgst, err)
}
}
return err
}
func init() {
GCCmd.Flags().BoolVarP(&dryRun, "dry-run", "d", false, "do everything expect remove the blobs")
}
var dryRun bool
// GCCmd is the cobra command that corresponds to the garbage-collect subcommand
var GCCmd = &cobra.Command{
Use: "garbage-collect <config>",
Short: "`garbage-collect` deletes layers not referenced by any manifests",
Long: "`garbage-collect` deletes layers not referenced by any manifests",
Run: func(cmd *cobra.Command, args []string) {
config, err := resolveConfiguration(args)
if err != nil {
fmt.Fprintf(os.Stderr, "configuration error: %v\n", err)
cmd.Usage()
os.Exit(1)
}
driver, err := factory.Create(config.Storage.Type(), config.Storage.Parameters())
if err != nil {
fmt.Fprintf(os.Stderr, "failed to construct %s driver: %v", config.Storage.Type(), err)
os.Exit(1)
}
ctx := context.Background()
ctx, err = configureLogging(ctx, config)
if err != nil {
fmt.Fprintf(os.Stderr, "unable to configure logging with config: %s", err)
os.Exit(1)
}
k, err := libtrust.GenerateECP256PrivateKey()
if err != nil {
fmt.Fprint(os.Stderr, err)
os.Exit(1)
}
registry, err := storage.NewRegistry(ctx, driver, storage.DisableSchema1Signatures, storage.Schema1SigningKey(k))
if err != nil {
fmt.Fprintf(os.Stderr, "failed to construct registry: %v", err)
os.Exit(1)
}
err = markAndSweep(ctx, driver, registry)
if err != nil {
fmt.Fprintf(os.Stderr, "failed to garbage collect: %v", err)
os.Exit(1)
}
},
}