Refactor the repository retrieval in get_dr_push

closes #1275

CHANGES/1275.misc

@@ -0,0 +1,2 @@
+Ensured repositories are correctly retrieved or initialized when handling concurrent requests
+during the push operation.

pulp_container/app/registry_api.py

@@ -17,6 +17,7 @@
 
 from django.core.files.storage import default_storage as storage
 from django.core.files.base import ContentFile, File
+from django.core.exceptions import ObjectDoesNotExist
 from django.db import IntegrityError, transaction
 from django.shortcuts import get_object_or_404
 
@@ -25,7 +26,7 @@
 from pulpcore.plugin.models import Artifact, ContentArtifact, UploadChunk
 from pulpcore.plugin.files import PulpTemporaryUploadedFile
 from pulpcore.plugin.tasking import add_and_remove, dispatch
-from pulpcore.plugin.util import get_objects_for_user
+from pulpcore.plugin.util import get_objects_for_user, get_url
 from rest_framework.exceptions import (
     AuthenticationFailed,
     NotAuthenticated,
@@ -291,32 +292,7 @@ def get_dr_push(self, request, path, create=False):
             distribution = models.ContainerDistribution.objects.get(base_path=path)
         except models.ContainerDistribution.DoesNotExist:
             if create:
-                try:
-                    with transaction.atomic():
-                        repo_serializer = serializers.ContainerPushRepositorySerializer(
-                            data={"name": path}, context={"request": request}
-                        )
-                        repo_serializer.is_valid(raise_exception=True)
-                        repository = repo_serializer.create(repo_serializer.validated_data)
-                        repo_href = serializers.ContainerPushRepositorySerializer(
-                            repository, context={"request": request}
-                        ).data["pulp_href"]
-
-                        dist_serializer = serializers.ContainerDistributionSerializer(
-                            data={"base_path": path, "name": path, "repository": repo_href}
-                        )
-                        dist_serializer.is_valid(raise_exception=True)
-                        distribution = dist_serializer.create(dist_serializer.validated_data)
-                except ValidationError:
-                    raise RepositoryInvalid(name=path)
-                except IntegrityError:
-                    # Seems like another process created our stuff already. Retry fetching it.
-                    distribution = models.ContainerDistribution.objects.get(base_path=path)
-                    repository = distribution.repository
-                    if repository:
-                        repository = repository.cast()
-                        if not repository.PUSH_ENABLED:
-                            raise RepositoryInvalid(name=path, message="Repository is read-only.")
+                distribution, repository = self.create_dr(path, request)
             else:
                 raise RepositoryNotFound(name=path)
         else:
@@ -349,6 +325,32 @@ def get_dr_push(self, request, path, create=False):
                 raise RepositoryNotFound(name=path)
         return distribution, repository
 
+    @transaction.atomic
+    def create_dr(self, path, request):
+        try:
+            repository = serializers.ContainerPushRepositorySerializer.get_or_create({"name": path})
+        except ObjectDoesNotExist:
+            # The repository of the push type could not be found or could not be created
+            raise RepositoryInvalid(name=path)
+
+        dist_serializer = serializers.ContainerDistributionSerializer(
+            data={"base_path": path, "name": path, "repository": get_url(repository)},
+            context={"request": request},
+        )
+        try:
+            dist_serializer.is_valid(raise_exception=True)
+            distribution = dist_serializer.create(dist_serializer.validated_data)
+        except (IntegrityError, ValidationError):
+            # seems like another process created our stuff already. Retry fetching it.
+            distribution = models.ContainerDistribution.objects.get(base_path=path)
+            repository = distribution.repository
+            if repository:
+                repository = repository.cast()
+                if not repository.PUSH_ENABLED:
+                    raise RepositoryInvalid(name=path, message="Repository is read-only.")
+
+        return distribution, repository
+
 
 class BearerTokenView(APIView):
     """

pulp_container/app/serializers.py

@@ -196,7 +196,7 @@ class Meta:
         model = models.ContainerRepository
 
 
-class ContainerPushRepositorySerializer(RepositorySerializer):
+class ContainerPushRepositorySerializer(RepositorySerializer, GetOrCreateSerializerMixin):
     """
     Serializer for Container Push Repositories.
     """