ContainerRegistry: return ContentDescriptor from getManifest

Author: euanh

Sources/ContainerRegistry/Manifests.swift

@@ -45,9 +45,9 @@ public extension RegistryClient {
     func getManifest(
         repository: ImageReference.Repository,
         reference: any ImageReference.Reference
-    ) async throws -> ImageManifest {
+    ) async throws -> (ImageManifest, ContentDescriptor) {
         // See https://github.com/opencontainers/distribution-spec/blob/main/spec.md#pulling-manifests
-        let (data, _) = try await executeRequestThrowing(
+        let (data, response) = try await executeRequestThrowing(
             .get(
                 repository,
                 path: "manifests/\(reference)",
@@ -58,7 +58,14 @@ public extension RegistryClient {
             ),
             decodingErrors: [.notFound]
         )
-        return try decoder.decode(ImageManifest.self, from: data)
+        return (
+            try decoder.decode(ImageManifest.self, from: data),
+            ContentDescriptor(
+                mediaType: response.headerFields[.contentType] ?? "application/vnd.oci.image.manifest.v1+json",
+                digest: "\(digest(of: data))",
+                size: Int64(data.count)
+            )
+        )
     }
 
     func getIndex(

Sources/containertool/Extensions/RegistryClient+Layers.swift

@@ -16,7 +16,9 @@ import struct Foundation.Data
 import ContainerRegistry
 
 extension RegistryClient {
-    func getImageManifest(forImage image: ImageReference, architecture: String) async throws -> ImageManifest {
+    func getImageManifest(forImage image: ImageReference, architecture: String) async throws -> (
+        ImageManifest, ContentDescriptor
+    ) {
         // We pushed the amd64 tag but it points to a single-architecture index, not directly to a manifest
         // if we get an index we should get a manifest, otherwise we might get a manifest directly
 

Sources/containertool/containertool.swift

@@ -249,12 +249,13 @@ extension RegistryClient {
 
         let baseImageManifest: ImageManifest
         let baseImageConfiguration: ImageConfiguration
+        let baseImageDescriptor: ContentDescriptor
         if let source {
-            baseImageManifest = try await source.getImageManifest(
+            (baseImageManifest, baseImageDescriptor) = try await source.getImageManifest(
                 forImage: baseImage,
                 architecture: architecture
             )
-            log("Found base image manifest: \(baseImageManifest.digest)")
+            log("Found base image manifest: \(baseImageDescriptor.digest)")
 
             baseImageConfiguration = try await source.getImageConfiguration(
                 forImage: baseImage,

Tests/ContainerRegistryTests/SmokeTests.swift

@@ -148,7 +148,10 @@ struct SmokeTests {
             manifest: test_manifest
         )
 
-        let manifest = try await client.getManifest(repository: repository, reference: ImageReference.Tag("latest"))
+        let (manifest, _) = try await client.getManifest(
+            repository: repository,
+            reference: ImageReference.Tag("latest")
+        )
         #expect(manifest.schemaVersion == 2)
         #expect(manifest.config.mediaType == "application/vnd.docker.container.image.v1+json")
         #expect(manifest.layers.count == 1)
@@ -187,7 +190,7 @@ struct SmokeTests {
             manifest: test_manifest
         )
 
-        let manifest = try await client.getManifest(
+        let (manifest, _) = try await client.getManifest(
             repository: repository,
             reference: test_manifest.digest
         )