treewide: introduce osbase package and move things around
All except localregistry moved from metropolis/pkg to osbase,
localregistry moved to metropolis/test as its only used there anyway.
Change-Id: If1a4bf377364bef0ac23169e1b90379c71b06d72
Reviewed-on: https://review.monogon.dev/c/monogon/+/3079
Tested-by: Jenkins CI
Reviewed-by: Serge Bazanski <serge@monogon.tech>
diff --git a/metropolis/test/localregistry/localregistry.go b/metropolis/test/localregistry/localregistry.go
new file mode 100644
index 0000000..120eb61
--- /dev/null
+++ b/metropolis/test/localregistry/localregistry.go
@@ -0,0 +1,172 @@
+// Package localregistry implements a read-only OCI Distribution / Docker
+// V2 container image registry backed by local layers.
+package localregistry
+
+import (
+ "bytes"
+ "encoding/json"
+ "fmt"
+ "io"
+ "log"
+ "net/http"
+ "os"
+ "path/filepath"
+ "regexp"
+ "strconv"
+
+ "github.com/bazelbuild/rules_go/go/runfiles"
+ "github.com/docker/distribution"
+ "github.com/docker/distribution/manifest/manifestlist"
+ "github.com/docker/distribution/manifest/ocischema"
+ "github.com/docker/distribution/manifest/schema2"
+ "github.com/docker/distribution/reference"
+ "github.com/opencontainers/go-digest"
+ "google.golang.org/protobuf/encoding/prototext"
+
+ "source.monogon.dev/metropolis/test/localregistry/spec"
+)
+
+type Server struct {
+ manifests map[string][]byte
+ blobs map[digest.Digest]blobMeta
+}
+
+type blobMeta struct {
+ filePath string
+ mediaType string
+ contentLength int64
+}
+
+func manifestDescriptorFromBazel(image *spec.Image) (manifestlist.ManifestDescriptor, error) {
+ indexPath, err := runfiles.Rlocation(filepath.Join("_main", image.Path, "index.json"))
+ if err != nil {
+ return manifestlist.ManifestDescriptor{}, fmt.Errorf("while locating manifest list file: %w", err)
+ }
+
+ manifestListRaw, err := os.ReadFile(indexPath)
+ if err != nil {
+ return manifestlist.ManifestDescriptor{}, fmt.Errorf("while opening manifest list file: %w", err)
+ }
+
+ var imageManifestList manifestlist.ManifestList
+ if err := json.Unmarshal(manifestListRaw, &imageManifestList); err != nil {
+ return manifestlist.ManifestDescriptor{}, fmt.Errorf("while unmarshaling manifest list for %q: %w", image.Name, err)
+ }
+
+ if len(imageManifestList.Manifests) != 1 {
+ return manifestlist.ManifestDescriptor{}, fmt.Errorf("unexpected manifest list length > 1")
+ }
+
+ return imageManifestList.Manifests[0], nil
+}
+
+func manifestFromBazel(s *Server, image *spec.Image, md manifestlist.ManifestDescriptor) (ocischema.Manifest, error) {
+ manifestPath, err := runfiles.Rlocation(filepath.Join("_main", image.Path, "blobs", md.Digest.Algorithm().String(), md.Digest.Hex()))
+ if err != nil {
+ return ocischema.Manifest{}, fmt.Errorf("while locating manifest file: %w", err)
+ }
+ manifestRaw, err := os.ReadFile(manifestPath)
+ if err != nil {
+ return ocischema.Manifest{}, fmt.Errorf("while opening manifest file: %w", err)
+ }
+
+ var imageManifest ocischema.Manifest
+ if err := json.Unmarshal(manifestRaw, &imageManifest); err != nil {
+ return ocischema.Manifest{}, fmt.Errorf("while unmarshaling manifest for %q: %w", image.Name, err)
+ }
+
+ // For Digest lookups
+ s.manifests[image.Name] = manifestRaw
+ s.manifests[md.Digest.String()] = manifestRaw
+
+ return imageManifest, nil
+}
+
+func addBazelBlobFromDescriptor(s *Server, image *spec.Image, dd distribution.Descriptor) error {
+ path, err := runfiles.Rlocation(filepath.Join("_main", image.Path, "blobs", dd.Digest.Algorithm().String(), dd.Digest.Hex()))
+ if err != nil {
+ return fmt.Errorf("while locating blob: %w", err)
+ }
+ s.blobs[dd.Digest] = blobMeta{filePath: path, mediaType: dd.MediaType, contentLength: dd.Size}
+ return nil
+}
+
+func FromBazelManifest(mb []byte) (*Server, error) {
+ var bazelManifest spec.Manifest
+ if err := prototext.Unmarshal(mb, &bazelManifest); err != nil {
+ log.Fatalf("failed to parse manifest: %v", err)
+ }
+ s := Server{
+ manifests: make(map[string][]byte),
+ blobs: make(map[digest.Digest]blobMeta),
+ }
+ for _, i := range bazelManifest.Images {
+ md, err := manifestDescriptorFromBazel(i)
+ if err != nil {
+ return nil, err
+ }
+
+ if err := addBazelBlobFromDescriptor(&s, i, md.Descriptor); err != nil {
+ return nil, err
+ }
+
+ m, err := manifestFromBazel(&s, i, md)
+ if err != nil {
+ return nil, err
+ }
+
+ if err := addBazelBlobFromDescriptor(&s, i, m.Config); err != nil {
+ return nil, err
+ }
+ for _, l := range m.Layers {
+ if err := addBazelBlobFromDescriptor(&s, i, l); err != nil {
+ return nil, err
+ }
+ }
+ }
+ return &s, nil
+}
+
+var (
+ versionCheckEp = regexp.MustCompile(`^/v2/$`)
+ manifestEp = regexp.MustCompile("^/v2/(" + reference.NameRegexp.String() + ")/manifests/(" + reference.TagRegexp.String() + "|" + digest.DigestRegexp.String() + ")$")
+ blobEp = regexp.MustCompile("^/v2/(" + reference.NameRegexp.String() + ")/blobs/(" + digest.DigestRegexp.String() + ")$")
+)
+
+func (s *Server) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+ if req.Method != http.MethodGet && req.Method != http.MethodHead {
+ w.WriteHeader(http.StatusMethodNotAllowed)
+ fmt.Fprintf(w, "Registry is read-only, only GET and HEAD are allowed\n")
+ return
+ }
+ w.Header().Set("Content-Type", "application/json")
+ if versionCheckEp.MatchString(req.URL.Path) {
+ w.WriteHeader(http.StatusOK)
+ fmt.Fprintf(w, "{}")
+ return
+ } else if matches := manifestEp.FindStringSubmatch(req.URL.Path); len(matches) > 0 {
+ name := matches[1]
+ manifest, ok := s.manifests[name]
+ if !ok {
+ w.WriteHeader(http.StatusNotFound)
+ fmt.Fprintf(w, "Image not found")
+ return
+ }
+ w.Header().Set("Content-Type", schema2.MediaTypeManifest)
+ w.Header().Set("Content-Length", strconv.FormatInt(int64(len(manifest)), 10))
+ w.WriteHeader(http.StatusOK)
+ io.Copy(w, bytes.NewReader(manifest))
+ } else if matches := blobEp.FindStringSubmatch(req.URL.Path); len(matches) > 0 {
+ bm, ok := s.blobs[digest.Digest(matches[2])]
+ if !ok {
+ w.WriteHeader(http.StatusNotFound)
+ fmt.Fprintf(w, "Blob not found")
+ return
+ }
+ w.Header().Set("Content-Type", bm.mediaType)
+ w.Header().Set("Content-Length", strconv.FormatInt(bm.contentLength, 10))
+ http.ServeFile(w, req, bm.filePath)
+ } else {
+ w.WriteHeader(http.StatusNotFound)
+ }
+}