Adjust 500 message exception for image pull when content is missing o…

…n the FS.

closes #555

(cherry picked from commit df24d16)

CHANGES/555.bugfix

@@ -0,0 +1 @@
+Return a more concise message exception on 500 during image pull when content is missing on the FS.

pulp_container/app/registry.py

@@ -1,5 +1,6 @@
 import logging
 import os
+from gettext import gettext as _
 
 from asgiref.sync import sync_to_async
 
@@ -61,17 +62,15 @@ async def _dispatch(file, headers):
             The :class:`aiohttp.web.FileResponse` for the file.
 
         """
+        path = os.path.join(settings.MEDIA_ROOT, file.name)
+        if not os.path.exists(path):
+            raise Exception(_("Expected path '{}' is not found").format(path))
+
         full_headers = MultiDict()
 
         full_headers["Content-Type"] = headers["Content-Type"]
         full_headers["Docker-Content-Digest"] = headers["Docker-Content-Digest"]
         full_headers["Docker-Distribution-API-Version"] = "registry/2.0"
-        full_headers["Content-Length"] = str(file.size)
-        full_headers["Content-Disposition"] = "attachment; filename={n}".format(
-            n=os.path.basename(file.name)
-        )
-
-        path = os.path.join(settings.MEDIA_ROOT, file.name)
         file_response = web.FileResponse(path, headers=full_headers)
         return file_response
 
@@ -114,7 +113,7 @@ async def get_tag(self, request):
             and tag.tagged_manifest.media_type not in accepted_media_types
         ):
             log.warn(
-                "OCI format found, but the client only accepts {accepted_media_types}.".format(
+                _("OCI format found, but the client only accepts {accepted_media_types}.").format(
                     accepted_media_types=accepted_media_types
                 )
             )

pulp_container/app/schema_convert.py

@@ -6,6 +6,9 @@
 import itertools
 import json
 import logging
+
+from gettext import gettext as _
+
 from collections import namedtuple
 from jwkest import jws, jwk, ecc
 
@@ -323,4 +326,11 @@ def _get_manifest_dict(manifest):
 
 
 def _get_dict(artifact):
-    return json.load(artifact.file)
+    try:
+        return json.load(artifact.file)
+    except FileNotFoundError:
+        raise Exception(
+            _(
+                "Expected manifest file 'sha256:{}' needed for schema conversion is not found"
+            ).format(artifact.sha256)
+        )