a4c70fe157
One potential failure mode is an empty file which bubbles up as an EOF error, leading to all pulls and listing operations failing. Instead, continue and warn about the corrupt manifest. This also allows re-pulling the corrupt manifest to repair the system.
130 lines
2.4 KiB
Go
130 lines
2.4 KiB
Go
package server
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import (
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"crypto/sha256"
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"errors"
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"fmt"
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"io"
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"os"
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)
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type Layer struct {
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MediaType string `json:"mediaType"`
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Digest string `json:"digest"`
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Size int64 `json:"size"`
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From string `json:"from,omitempty"`
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status string
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}
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func NewLayer(r io.Reader, mediatype string) (Layer, error) {
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blobs, err := GetBlobsPath("")
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if err != nil {
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return Layer{}, err
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}
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temp, err := os.CreateTemp(blobs, "sha256-")
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if err != nil {
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return Layer{}, err
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}
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defer temp.Close()
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defer os.Remove(temp.Name())
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sha256sum := sha256.New()
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n, err := io.Copy(io.MultiWriter(temp, sha256sum), r)
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if err != nil {
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return Layer{}, err
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}
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if err := temp.Close(); err != nil {
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return Layer{}, err
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}
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digest := fmt.Sprintf("sha256:%x", sha256sum.Sum(nil))
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blob, err := GetBlobsPath(digest)
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if err != nil {
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return Layer{}, err
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}
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status := "using existing layer"
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if _, err := os.Stat(blob); err != nil {
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status = "creating new layer"
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if err := os.Rename(temp.Name(), blob); err != nil {
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return Layer{}, err
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}
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if err := os.Chmod(blob, 0o644); err != nil {
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return Layer{}, err
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}
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}
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return Layer{
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MediaType: mediatype,
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Digest: digest,
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Size: n,
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status: fmt.Sprintf("%s %s", status, digest),
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}, nil
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}
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func NewLayerFromLayer(digest, mediatype, from string) (Layer, error) {
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if digest == "" {
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return Layer{}, errors.New("creating new layer from layer with empty digest")
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}
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blob, err := GetBlobsPath(digest)
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if err != nil {
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return Layer{}, err
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}
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fi, err := os.Stat(blob)
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if err != nil {
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return Layer{}, err
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}
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return Layer{
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MediaType: mediatype,
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Digest: digest,
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Size: fi.Size(),
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From: from,
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status: fmt.Sprintf("using existing layer %s", digest),
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}, nil
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}
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func (l *Layer) Open() (io.ReadSeekCloser, error) {
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if l.Digest == "" {
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return nil, errors.New("opening layer with empty digest")
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}
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blob, err := GetBlobsPath(l.Digest)
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if err != nil {
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return nil, err
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}
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return os.Open(blob)
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}
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func (l *Layer) Remove() error {
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if l.Digest == "" {
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return nil
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}
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// Ignore corrupt manifests to avoid blocking deletion of layers that are freshly orphaned
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ms, err := Manifests(true)
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if err != nil {
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return err
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}
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for _, m := range ms {
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for _, layer := range append(m.Layers, m.Config) {
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if layer.Digest == l.Digest {
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// something is using this layer
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return nil
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}
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}
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}
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blob, err := GetBlobsPath(l.Digest)
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if err != nil {
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return err
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}
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return os.Remove(blob)
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}
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