Handles an exception for non-existing repository

fixes: #1703

CHANGES/1703.bugfix

@@ -0,0 +1,2 @@
+Fixed an issue causing an HTTP 500 error when a GET request for a non-existing
+blob was made to a distribution with only a `repository_version` set.

pulp_container/app/registry_api.py

@@ -297,13 +297,15 @@ def get_drv_pull(self, path):
         except models.ContainerDistribution.DoesNotExist:
             # get a pull-through cache distribution whose base_path is a substring of the path
             return self.get_pull_through_drv(path)
-        if distribution.repository:
+        repository = distribution.repository
+        if repository:
             repository_version = distribution.repository.latest_version()
         elif distribution.repository_version:
             repository_version = distribution.repository_version
+            repository = repository_version.repository
         else:
             raise RepositoryNotFound(name=path)
-        return distribution, distribution.repository, repository_version
+        return distribution, repository, repository_version
 
     def get_pull_through_drv(self, path):
         pull_through_cache_distribution = (

pulp_container/tests/functional/api/test_pull_content.py

@@ -28,7 +28,7 @@
     REGISTRY_V2_REPO_HELLO_WORLD,
     PULP_HELLO_WORLD_LINUX_TAG,
 )
-from pulp_container.constants import EMPTY_BLOB, MEDIA_TYPE
+from pulp_container.constants import EMPTY_BLOB, EMPTY_JSON, MEDIA_TYPE
 
 from pulpcore.client.pulp_container import (
     ContainerContainerDistribution,
@@ -279,6 +279,18 @@ def test_pull_nonexistent_image(self):
         with self.assertRaises(exceptions.CalledProcessError):
             registry.pull(local_url)
 
+    def test_pull_nonexistent_blob(self):
+        """
+        Verify that a GET request to a nonexistent BLOB will be properly handled
+        instead of outputting a stacktrace.
+        """
+        blob_path = "/v2/{}/blobs/{}".format(self.distribution_with_repo.base_path, EMPTY_JSON)
+        non_existing_blob_url = urljoin(self.cfg.get_base_url(), blob_path)
+
+        auth = get_auth_for_url(non_existing_blob_url)
+        content_response = requests.get(non_existing_blob_url, auth=auth)
+        assert content_response.status_code, 404
+
 
 class PullOnDemandContentTestCase(unittest.TestCase):
     """Verify whether on-demand served images by Pulp can be pulled."""