Have appr blob redirect to storage when possible (#466)

endpoints/appr/cnr_backend.py

@@ -15,6 +15,7 @@
 
 from flask import request
 from app import storage
+from digest.digest_tools import Digest, InvalidDigestException
 from endpoints.appr.models_cnr import model
 from util.request import get_request_ip
 
@@ -119,6 +120,12 @@ def __init__(self, package_name, blob, b64_encoded=True):
 
     @classmethod
     def upload_url(cls, digest):
+        # Ensure we have a valid digest.
+        try:
+            Digest.parse_digest("sha256:%s" % digest)
+        except InvalidDigestException:
+            return None
+
         return "cnr/blobs/sha256/%s/%s" % (digest[0:2], digest)
 
     def save(self, content_media_type):
@@ -131,6 +138,9 @@ def delete(cls, package_name, digest):
     @classmethod
     def _fetch_b64blob(cls, package_name, digest):
         blobpath = cls.upload_url(digest)
+        if blobpath is None:
+            raise_package_not_found(package_name, digest)
+
         locations = model.get_blob_locations(digest)
         if not locations:
             raise_package_not_found(package_name, digest)
@@ -139,6 +149,9 @@ def _fetch_b64blob(cls, package_name, digest):
     @classmethod
     def download_url(cls, package_name, digest):
         blobpath = cls.upload_url(digest)
+        if blobpath is None:
+            raise_package_not_found(package_name, digest)
+
         locations = model.get_blob_locations(digest)
         if not locations:
             raise_package_not_found(package_name, digest)

endpoints/appr/registry.py

@@ -18,7 +18,7 @@
     UnauthorizedAccess,
     Unsupported,
 )
-from flask import jsonify, request
+from flask import jsonify, request, redirect
 
 from app import app, model_cache
 from auth.auth_context import get_authenticated_user
@@ -78,7 +78,6 @@ def login():
     return jsonify({"token": "basic " + auth.decode("ascii")})
 
 
-# @TODO: Redirect to S3 url
 @appr_bp.route(
     "/api/v1/packages/<string:namespace>/<string:package_name>/blobs/sha256/<string:digest>",
     methods=["GET"],
@@ -92,6 +91,11 @@ def blobs(namespace, package_name, digest):
     reponame = repo_name(namespace, package_name)
     data = cnr_registry.pull_blob(reponame, digest, blob_class=Blob)
     json_format = request.args.get("format", None) == "json"
+    if not json_format:
+        download_url = Blob.download_url(reponame, digest)
+        if download_url:
+            return redirect(download_url)
+
     return _pull(data, json_format=json_format)