fix: return a response that docker understands better when it doesn't find a manifest

index.test.ts

@@ -89,7 +89,9 @@ describe("v2 manifests", () => {
         {
           code: "MANIFEST_UNKNOWN",
           message: "manifest unknown",
-          detail: "This error is returned when the manifest, identified by name and tag is unknown to the repository.",
+          detail: {
+            Tag: "reference",
+          },
         },
       ],
     });

src/router.ts

@@ -1,7 +1,7 @@
 import { Router } from "itty-router";
 import { BlobUnknownError, ManifestUnknownError } from "./v2-errors";
 import { InternalError, ServerError } from "./errors";
-import { errorString, wrap } from "./utils";
+import { errorString, jsonHeaders, wrap } from "./utils";
 import { hexToDigest } from "./user";
 import { ManifestTagsListTooBigError } from "./v2-responses";
 import { Env } from "..";
@@ -66,7 +66,7 @@ v2Router.delete("/:name+/manifests/:reference", async (req, env: Env) => {
   // Reference is ALWAYS a sha256
   const manifest = await env.REGISTRY.head(`${name}/manifests/${reference}`);
   if (manifest === null) {
-    return new Response(JSON.stringify(ManifestUnknownError), { status: 404 });
+    return new Response(JSON.stringify(ManifestUnknownError(reference)), { status: 404, headers: jsonHeaders() });
   }
   const limitInt = parseInt(limit?.toString() ?? "1000", 10);
   const tags = await env.REGISTRY.list({
@@ -162,7 +162,7 @@ v2Router.head("/:name+/manifests/:reference", async (req, env: Env) => {
   }
 
   if (checkManifestResponse === null || !checkManifestResponse.exists)
-    return new Response(JSON.stringify(ManifestUnknownError), { status: 404 });
+    return new Response(JSON.stringify(ManifestUnknownError(reference)), { status: 404, headers: jsonHeaders() });
 
   return new Response(null, {
     headers: {
@@ -221,7 +221,9 @@ v2Router.get("/:name+/manifests/:reference", async (req, env: Env, context: Exec
     break;
   }
 
-  if (getManifestResponse === null) return new Response(JSON.stringify(ManifestUnknownError), { status: 404 });
+  if (getManifestResponse === null)
+    return new Response(JSON.stringify(ManifestUnknownError(reference)), { status: 404, headers: jsonHeaders() });
+
   return new Response(getManifestResponse.stream, {
     headers: {
       "Content-Length": getManifestResponse.size.toString(),

src/utils.ts

@@ -63,3 +63,7 @@ export function errorString(err: unknown): string {
 export async function wrap<T, E = unknown>(fn: Promise<T>): Promise<[T, null] | [null, E]> {
   return fn.then((data) => [data, null] as [T, null]).catch((err) => [null, err as unknown as E] as [null, E]);
 }
+
+export function jsonHeaders(): { "content-type": "application/json" } {
+  return { "content-type": "application/json" };
+}

src/v2-errors.ts

@@ -1,19 +1,24 @@
-export const ManifestUnknownError = {
-  errors: [
-    {
-      code: "MANIFEST_UNKNOWN",
-      message: "manifest unknown",
-      detail: "This error is returned when the manifest, identified by name and tag is unknown to the repository.",
-    },
-  ],
-};
+export const ManifestUnknownError = (tag: string) =>
+  ({
+    errors: [
+      {
+        code: "MANIFEST_UNKNOWN",
+        message: "manifest unknown",
+        detail: {
+          Tag: tag,
+        },
+      },
+    ],
+  } as const);
 
 export const BlobUnknownError = {
   errors: [
     {
       code: "BLOB_UNKNOWN",
       message: "blob unknown to registry",
-      detail: "This error may be returned when a manifest blob is unknown to the registry.",
+      detail: {
+        message: "This error may be returned when a layer blob is unknown to the registry.",
+      },
     },
   ],
 };