Implemented route /v2/_catalog API functionality (#19)

src/registry/r2.ts

@@ -19,6 +19,7 @@ import {
   FinishedUploadObject,
   GetLayerResponse,
   GetManifestResponse,
+  ListRepositoriesResponse,
   PutManifestResponse,
   Registry,
   RegistryError,
@@ -130,6 +131,34 @@ export class R2Registry implements Registry {
     return checkManifestResponse;
   }
 
+  async listRepositories(limit?: number, last?: string): Promise<RegistryError | ListRepositoriesResponse> {
+    const env = this.env;
+    const options = {
+      limit: limit ? limit : 1000,
+      delimiter: "/",
+      startAfter: last,
+    }
+    const r2Objects = (await env.REGISTRY.list(options));
+
+    let truncated = r2Objects.truncated;
+    let cursor = truncated ? r2Objects.cursor : undefined;
+
+    while (truncated) {
+      const next = await env.REGISTRY.list({
+        ...options,
+        cursor: cursor,
+      });
+      r2Objects.objects.push(...next.objects);
+
+      truncated = next.truncated;
+      cursor = next.cursor
+    }
+
+    return {
+      repositories: r2Objects.delimitedPrefixes.map((name)=> name.endsWith('/') ? name.slice(0, -1) : name)
+    };
+  }
+
   async putManifest(
     name: string,
     reference: string,

src/registry/registry.ts

@@ -43,6 +43,12 @@ export type CheckManifestResponse =
       exists: false;
     };
 
+export type ListRepositoriesResponse =
+  {
+    repositories: string[];
+  }
+
+
 // Response layerExists call
 export type CheckLayerResponse =
   | {
@@ -102,6 +108,9 @@ export interface Registry {
   // checks whether the manifest exists in the registry
   manifestExists(namespace: string, tag: string): Promise<CheckManifestResponse | RegistryError>;
 
+  // listing repositories in the registry
+  listRepositories(limit?: number, last?: string): Promise<ListRepositoriesResponse | RegistryError>;
+
   // gets the manifest by namespace + digest
   getManifest(namespace: string, digest: string): Promise<GetManifestResponse | RegistryError>;
 

src/router.ts

@@ -25,6 +25,17 @@ v2Router.get("/", async (_req, _env: Env) => {
   return new Response();
 });
 
+v2Router.get("/_catalog", async (req, env: Env) => {
+  const { n, last } = req.query;
+  const res = await env.REGISTRY_CLIENT.listRepositories(
+    n ? parseInt(n?.toString()) : undefined,
+    last?.toString()
+  );
+
+  return new Response(JSON.stringify(res));
+});
+
+
 v2Router.delete("/:name+/manifests/:reference", async (req, env: Env) => {
   // deleting a manifest works by retrieving the """main""" manifest that its key is a sha,
   // and then going through every tag and removing it