Fixes: Distribution API

Signed-off-by: Kan Cheung <[email protected]>

Author: kanlac

pkg/api/handlers/compat/distribution.go

@@ -0,0 +1,88 @@
+//go:build !remote
+
+package compat
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/containers/image/v5/docker"
+	"github.com/containers/image/v5/docker/reference"
+	"github.com/containers/image/v5/manifest"
+	"github.com/containers/podman/v5/pkg/api/handlers/utils"
+	registrytypes "github.com/docker/docker/api/types/registry"
+	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
+)
+
+func InspectDistribution(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "application/json")
+
+	name := utils.GetName(r)
+
+	ref, err := reference.ParseAnyReference(name)
+	if err != nil {
+		utils.Error(w, http.StatusBadRequest, fmt.Errorf("error parsing image reference %q: %w", name, err))
+		return
+	}
+
+	namedRef, ok := ref.(reference.Named)
+	if !ok {
+		if _, ok := ref.(reference.Digested); ok {
+			// full image ID
+			utils.Error(w, http.StatusBadRequest, fmt.Errorf("no manifest found for full image ID"))
+			return
+		}
+		utils.Error(w, http.StatusBadRequest, fmt.Errorf("unknown image reference format: %s", name))
+		return
+	}
+
+	namedRef = reference.TagNameOnly(namedRef)
+
+	imgRef, err := docker.NewReference(namedRef)
+	if err != nil {
+		utils.Error(w, http.StatusInternalServerError, fmt.Errorf("error creating image reference: %w", err))
+		return
+	}
+
+	imgSrc, err := imgRef.NewImageSource(r.Context(), nil)
+	if err != nil {
+		utils.Error(w, http.StatusInternalServerError, fmt.Errorf("error getting image source: %w", err))
+		return
+	}
+	defer imgSrc.Close()
+
+	manBlob, manType, err := imgSrc.GetManifest(r.Context(), nil)
+	if err != nil {
+		utils.Error(w, http.StatusInternalServerError, fmt.Errorf("error getting manifest: %w", err))
+		return
+	}
+
+	digest, err := manifest.Digest(manBlob)
+	if err != nil {
+		utils.Error(w, http.StatusInternalServerError, fmt.Errorf("error getting manifest digest: %w", err))
+		return
+	}
+
+	// todo: handle other manifest types
+	ociIndex, err := manifest.OCI1IndexFromManifest(manBlob)
+	if err != nil {
+		utils.Error(w, http.StatusInternalServerError, fmt.Errorf("error getting OCI index from manifest: %w", err))
+		return
+	}
+
+	platforms := make([]ocispec.Platform, len(ociIndex.Manifests))
+	for i, m := range ociIndex.Manifests {
+		platforms[i] = *m.Platform
+	}
+
+	distributionInspect := registrytypes.DistributionInspect{
+		Descriptor: ocispec.Descriptor{
+			Digest:    digest,
+			Size:      int64(len(manBlob)),
+			MediaType: manType,
+		},
+		Platforms: platforms,
+	}
+
+	utils.WriteResponse(w, http.StatusOK, distributionInspect)
+}

pkg/api/server/register_distribution.go

@@ -3,13 +3,16 @@
 package server
 
 import (
+	"net/http"
+
 	"github.com/containers/podman/v5/pkg/api/handlers/compat"
 	"github.com/gorilla/mux"
 )
 
 func (s *APIServer) registerDistributionHandlers(r *mux.Router) error {
-	r.HandleFunc(VersionedPath("/distribution/{name}/json"), compat.UnsupportedHandler)
+	r.HandleFunc(VersionedPath("/distribution/{name:.*}/json"), s.APIHandler(compat.InspectDistribution)).Methods(http.MethodGet)
+	r.HandleFunc(VersionedPath("/libpod/distribution/{name:.*}/json"), s.APIHandler(compat.InspectDistribution)).Methods(http.MethodGet)
 	// Added non version path to URI to support docker non versioned paths
-	r.HandleFunc("/distribution/{name}/json", compat.UnsupportedHandler)
+	r.HandleFunc("/distribution/{name:.*}/json", s.APIHandler(compat.InspectDistribution)).Methods(http.MethodGet)
 	return nil
 }

test/apiv2/python/rest_api/test_v2_0_0_distribution.py

@@ -0,0 +1,46 @@
+import unittest
+
+import requests
+from .fixtures import APITestCase
+
+
+class DistributionTestCase(APITestCase):
+    def test_distribution_inspect(self):
+        # Make sure the image exists
+        r = requests.post(self.uri("/images/pull?reference=alpine:latest"), timeout=15)
+        self.assertEqual(r.status_code, 200, r.text)
+        
+        r = requests.get(self.podman_url + "/v1.40/distribution/alpine/json")
+        self.assertEqual(r.status_code, 200, r.text)
+        
+        result = r.json()
+        self.assertIn("Descriptor", result)
+        self.assertIn("Platforms", result)
+        
+        descriptor = result["Descriptor"]
+        self.assertIn("mediaType", descriptor)
+        self.assertIn("digest", descriptor)
+        self.assertIn("size", descriptor)
+        
+        for platform in result["Platforms"]:
+            self.assertIn("architecture", platform)
+            self.assertIn("os", platform)
+        
+    def test_distribution_inspect_invalid_image(self):
+        r = requests.get(self.podman_url + "/v1.40/distribution/nonexistentimage/json")
+        self.assertIn(r.status_code, (404, 500), r.text)
+    
+    def test_distribution_inspect_with_tag(self):
+        r = requests.post(self.uri("/images/pull?reference=postgres:14.7"), timeout=15)
+        self.assertEqual(r.status_code, 200, r.text)
+        
+        r = requests.get(self.podman_url + "/v1.40/distribution/postgres:14.7/json")
+        self.assertEqual(r.status_code, 200, r.text)
+        
+        result = r.json()
+        self.assertIn("Descriptor", result)
+        self.assertIn("Platforms", result)
+
+
+if __name__ == "__main__":
+    unittest.main()