containertool: manifest and configuration functions should accept ImageReference arguments (#114)

Motivation
----------

`ContainerRegistry` methods follow the distribution API closely.
`containertool` defines some extensions which build more convenient
operations over these primitive functions. These extensions should
accept `ImageReference` arguments. Currently they take separate
repository and reference arguments and the caller needs to extract these
fields from the appropriate references. This provides an opportunity for
errors, such as trying to use the a reference with the wrong repository.

Modifications
-------------

`getImageManifest()`, `getImageConfiguration()` and
`putImageConfiguration()` now accept `ImageReference` arguments.

Result
------

The caller no longer has to extract the underlying fields, and the risk
of mixing them up is reduced.

Test Plan
---------

All tests continue to pass.

Author: euanh

Sources/ContainerRegistry/RegistryClient+ImageConfiguration.swift

@@ -15,29 +15,30 @@
 extension RegistryClient {
     /// Get an image configuration record from the registry.
     /// - Parameters:
-    ///   - repository: Name of the repository containing the record.
+    ///   - image: Reference to the image containing the record.
     ///   - digest: Digest of the record.
     /// - Returns: The image confguration record stored in `repository` with digest `digest`.
     /// - Throws: If the blob cannot be decoded as an `ImageConfiguration`.
     ///
     /// Image configuration records are stored as blobs in the registry.  This function retrieves the requested blob and tries to decode it as a configuration record.
-    public func getImageConfiguration(repository: String, digest: String) async throws -> ImageConfiguration {
-        try await getBlob(repository: repository, digest: digest)
+    public func getImageConfiguration(forImage image: ImageReference, digest: String) async throws -> ImageConfiguration
+    {
+        try await getBlob(repository: image.repository, digest: digest)
     }
 
     /// Upload an image configuration record to the registry.
     /// - Parameters:
-    ///   - repository: Name of the repository in which to store the record.
+    ///   - image: Reference to the image associated with the record.
     ///   - configuration: An image configuration record
     /// - Returns: An `ContentDescriptor` referring to the blob stored in the registry.
     /// - Throws: If the blob upload fails.
     ///
     /// Image configuration records are stored as blobs in the registry.  This function encodes the provided configuration record and stores it as a blob in the registry.
-    public func putImageConfiguration(repository: String, configuration: ImageConfiguration) async throws
+    public func putImageConfiguration(forImage image: ImageReference, configuration: ImageConfiguration) async throws
         -> ContentDescriptor
     {
         try await putBlob(
-            repository: repository,
+            repository: image.repository,
             mediaType: "application/vnd.oci.image.config.v1+json",
             data: configuration
         )

Sources/containertool/Extensions/RegistryClient+Layers.swift

@@ -16,23 +16,23 @@ import struct Foundation.Data
 import ContainerRegistry
 
 extension RegistryClient {
-    func getImageManifest(repository: String, reference: String, architecture: String) async throws -> ImageManifest {
+    func getImageManifest(forImage image: ImageReference, architecture: String) async throws -> ImageManifest {
         // 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
 
         do {
             // Try to retrieve a manifest.   If the object with this reference is actually an index, the content-type will not match and
             // an error will be thrown.
-            return try await getManifest(repository: repository, reference: reference)
+            return try await getManifest(repository: image.repository, reference: image.reference)
         } catch {
             // Try again, treating the top level object as an index.
             // This could be more efficient if the exception thrown by getManfiest() included the data it was unable to parse
-            let index = try await getIndex(repository: repository, reference: reference)
+            let index = try await getIndex(repository: image.repository, reference: image.reference)
             guard let manifest = index.manifests.first(where: { $0.platform?.architecture == architecture }) else {
                 throw "Could not find a suitable base image for \(architecture)"
             }
             // The index should not point to another index;   if it does, this call will throw a final error to be handled by the caller.
-            return try await getManifest(repository: repository, reference: manifest.digest)
+            return try await getManifest(repository: image.repository, reference: manifest.digest)
         }
     }
 

Sources/containertool/containertool.swift

@@ -129,14 +129,13 @@ enum AllowHTTP: String, ExpressibleByArgument, CaseIterable { case source, desti
         let baseimage_config: ImageConfiguration
         if let source {
             baseimage_manifest = try await source.getImageManifest(
-                repository: baseimage.repository,
-                reference: baseimage.reference,
+                forImage: baseimage,
                 architecture: architecture
             )
             log("Found base image manifest: \(baseimage_manifest.digest)")
 
             baseimage_config = try await source.getImageConfiguration(
-                repository: baseimage.repository,
+                forImage: baseimage,
                 digest: baseimage_manifest.config.digest
             )
             log("Found base image configuration: \(baseimage_manifest.config.digest)")
@@ -204,7 +203,7 @@ enum AllowHTTP: String, ExpressibleByArgument, CaseIterable { case source, desti
         )
 
         let config_blob = try await destination.putImageConfiguration(
-            repository: destination_image.repository,
+            forImage: destination_image,
             configuration: configuration
         )
 

Tests/ContainerRegistryTests/SmokeTests.swift

@@ -185,6 +185,7 @@ struct SmokeTests {
 
     @Test func testPutAndGetImageConfiguration() async throws {
         let repository = "testputandgetimageconfiguration"  // repository name must be lowercase
+        let image = ImageReference(registry: "registry", repository: repository, reference: "latest")
 
         let configuration = ImageConfiguration(
             created: "1996-12-19T16:39:57-08:00",
@@ -195,12 +196,12 @@ struct SmokeTests {
             history: [.init(created: "1996-12-19T16:39:57-08:00", author: "test", created_by: "smoketest")]
         )
         let config_descriptor = try await client.putImageConfiguration(
-            repository: repository,
+            forImage: image,
             configuration: configuration
         )
 
         let downloaded = try await client.getImageConfiguration(
-            repository: repository,
+            forImage: image,
             digest: config_descriptor.digest
         )