Address some review questions

Author: baronfel

Microsoft.NET.Build.Containers/Registry.cs

@@ -20,10 +20,6 @@ public record struct ManifestConfig(string mediaType, long size, string digest);
 public record struct ManifestLayer(string mediaType, long size, string digest, string[]? urls);
 public record struct ManifestV2(int schemaVersion, string tag, string mediaType, ManifestConfig config, List<ManifestLayer> layers);
 
-// not a complete list, only the subset that we support
-// public enum GoOS { linux, windows };
-// not a complete list, only the subset that we support
-// public enum GoArch { amd64, arm , arm64,  [JsonStringEnumMember("386")] x386 };
 public record struct PlatformInformation(string architecture, string os, string? variant, string[] features, [property:JsonPropertyName("os.version")][field: JsonPropertyName("os.version")] string? version);
 public record struct PlatformSpecificManifest(string mediaType, long size, string digest, PlatformInformation platform);
 public record struct ManifestListV2(int schemaVersion, string mediaType, PlatformSpecificManifest[] manifests);
@@ -170,7 +166,10 @@ async Task<HttpResponseMessage> GetBlob(string repositoryName, string digest)
     }
 
     private string? CreateRidForPlatform(PlatformInformation platform)
-    {
+    {   
+        // we only support linux and windows containers explicitly, so anything else we should skip past.
+        // there are theoretically other platforms/architectures that Docker supports (s390x?), but we are
+        // deliberately ignoring them without clear user signal.
         var osPart = platform.os switch
         {
             "linux" => "linux",

Test.Microsoft.NET.Build.Containers.Filesystem/RegistryTests.cs

@@ -18,7 +18,9 @@ public async Task GetFromRegistry()
         // TODO: The DOTNET_ROOT comes from the test host, but we have no idea what the SDK version is.
         var ridgraphfile = Path.Combine(Environment.GetEnvironmentVariable("DOTNET_ROOT"), "sdk", "7.0.100", "RuntimeIdentifierGraph.json");
 
-        Image downloadedImage = await registry.GetImageManifest(DockerRegistryManager.BaseImage, DockerRegistryManager.Net6ImageTag, "linux-x64", ridgraphfile); // don't need rid graph for local registry
+        // Don't need rid graph for local registry image pulls - since we're only pushing single image manifests (not manifest lists)
+        // as part of our setup, we could put literally anything in here. The file at the passed-in path would only get read when parsing manifests lists.
+        Image downloadedImage = await registry.GetImageManifest(DockerRegistryManager.BaseImage, DockerRegistryManager.Net6ImageTag, "linux-x64", ridgraphfile);
 
         Assert.IsNotNull(downloadedImage);
     }