package plugin // import "github.com/docker/docker/plugin" import ( "context" "fmt" "io" "io/ioutil" "os" "path/filepath" "runtime" "github.com/docker/docker/distribution/xfer" "github.com/docker/docker/image" "github.com/docker/docker/layer" "github.com/docker/docker/pkg/archive" "github.com/docker/docker/pkg/chrootarchive" "github.com/docker/docker/pkg/progress" digest "github.com/opencontainers/go-digest" specs "github.com/opencontainers/image-spec/specs-go/v1" "github.com/pkg/errors" "github.com/sirupsen/logrus" ) type blobstore interface { New() (WriteCommitCloser, error) Get(dgst digest.Digest) (io.ReadCloser, error) Size(dgst digest.Digest) (int64, error) } type basicBlobStore struct { path string } func newBasicBlobStore(p string) (*basicBlobStore, error) { tmpdir := filepath.Join(p, "tmp") if err := os.MkdirAll(tmpdir, 0700); err != nil { return nil, errors.Wrapf(err, "failed to mkdir %v", p) } return &basicBlobStore{path: p}, nil } func (b *basicBlobStore) New() (WriteCommitCloser, error) { f, err := ioutil.TempFile(filepath.Join(b.path, "tmp"), ".insertion") if err != nil { return nil, errors.Wrap(err, "failed to create temp file") } return newInsertion(f), nil } func (b *basicBlobStore) Get(dgst digest.Digest) (io.ReadCloser, error) { return os.Open(filepath.Join(b.path, string(dgst.Algorithm()), dgst.Hex())) } func (b *basicBlobStore) Size(dgst digest.Digest) (int64, error) { stat, err := os.Stat(filepath.Join(b.path, string(dgst.Algorithm()), dgst.Hex())) if err != nil { return 0, err } return stat.Size(), nil } func (b *basicBlobStore) gc(whitelist map[digest.Digest]struct{}) { for _, alg := range []string{string(digest.Canonical)} { items, err := ioutil.ReadDir(filepath.Join(b.path, alg)) if err != nil { continue } for _, fi := range items { if _, exists := whitelist[digest.Digest(alg+":"+fi.Name())]; !exists { p := filepath.Join(b.path, alg, fi.Name()) err := os.RemoveAll(p) logrus.Debugf("cleaned up blob %v: %v", p, err) } } } } // WriteCommitCloser defines object that can be committed to blobstore. type WriteCommitCloser interface { io.WriteCloser Commit() (digest.Digest, error) } type insertion struct { io.Writer f *os.File digester digest.Digester closed bool } func newInsertion(tempFile *os.File) *insertion { digester := digest.Canonical.Digester() return &insertion{f: tempFile, digester: digester, Writer: io.MultiWriter(tempFile, digester.Hash())} } func (i *insertion) Commit() (digest.Digest, error) { p := i.f.Name() d := filepath.Join(filepath.Join(p, "../../")) i.f.Sync() defer os.RemoveAll(p) if err := i.f.Close(); err != nil { return "", err } i.closed = true dgst := i.digester.Digest() if err := os.MkdirAll(filepath.Join(d, string(dgst.Algorithm())), 0700); err != nil { return "", errors.Wrapf(err, "failed to mkdir %v", d) } if err := os.Rename(p, filepath.Join(d, string(dgst.Algorithm()), dgst.Hex())); err != nil { return "", errors.Wrapf(err, "failed to rename %v", p) } return dgst, nil } func (i *insertion) Close() error { if i.closed { return nil } defer os.RemoveAll(i.f.Name()) return i.f.Close() } type downloadManager struct { blobStore blobstore tmpDir string blobs []digest.Digest configDigest digest.Digest } func (dm *downloadManager) Download(ctx context.Context, initialRootFS image.RootFS, os string, layers []xfer.DownloadDescriptor, progressOutput progress.Output) (image.RootFS, func(), error) { for _, l := range layers { b, err := dm.blobStore.New() if err != nil { return initialRootFS, nil, err } defer b.Close() rc, _, err := l.Download(ctx, progressOutput) if err != nil { return initialRootFS, nil, errors.Wrap(err, "failed to download") } defer rc.Close() r := io.TeeReader(rc, b) inflatedLayerData, err := archive.DecompressStream(r) if err != nil { return initialRootFS, nil, err } defer inflatedLayerData.Close() digester := digest.Canonical.Digester() if _, err := chrootarchive.ApplyLayer(dm.tmpDir, io.TeeReader(inflatedLayerData, digester.Hash())); err != nil { return initialRootFS, nil, err } initialRootFS.Append(layer.DiffID(digester.Digest())) d, err := b.Commit() if err != nil { return initialRootFS, nil, err } dm.blobs = append(dm.blobs, d) } return initialRootFS, nil, nil } func (dm *downloadManager) Put(dt []byte) (digest.Digest, error) { b, err := dm.blobStore.New() if err != nil { return "", err } defer b.Close() n, err := b.Write(dt) if err != nil { return "", err } if n != len(dt) { return "", io.ErrShortWrite } d, err := b.Commit() dm.configDigest = d return d, err } func (dm *downloadManager) Get(d digest.Digest) ([]byte, error) { return nil, fmt.Errorf("digest not found") } func (dm *downloadManager) RootFSFromConfig(c []byte) (*image.RootFS, error) { return configToRootFS(c) } func (dm *downloadManager) PlatformFromConfig(c []byte) (*specs.Platform, error) { // TODO: LCOW/Plugins. This will need revisiting. For now use the runtime OS return &specs.Platform{OS: runtime.GOOS}, nil }