Fix race condition inside SingleArtifactContentUploadSerializer

Assisted by: cursor-composer-2.5

(cherry picked from commit 94f63c3)

Author: gerrod3

CHANGES/+concurrent-artifact-file-reuse.bugfix

@@ -0,0 +1 @@
+Fixed a race condition when creating content with `file_url` or `upload` that could result in a duplicate artifact error.

pulpcore/plugin/serializers/content.py

@@ -3,7 +3,7 @@
 from tempfile import NamedTemporaryFile
 from urllib.parse import urlparse
 
-from django.db import DatabaseError
+from django.db import DatabaseError, IntegrityError
 from rest_framework.serializers import (
     CharField,
     FileField,
@@ -14,7 +14,6 @@
 from pulpcore.app.files import PulpTemporaryUploadedFile
 from pulpcore.app.models import Artifact, PulpTemporaryFile, Remote, Upload, UploadChunk
 from pulpcore.app.serializers import (
-    ArtifactSerializer,
     NoArtifactContentSerializer,
     RelatedField,
     SingleArtifactContentSerializer,
@@ -259,19 +258,21 @@ def deferred_validate(self, data):
             # if artifact already exists, let's use it
             try:
                 artifact = Artifact.objects.get(
-                    sha256=file.hashers["sha256"].hexdigest(),
-                    pulp_domain=get_domain_pk(),
+                    sha256=file.hashers["sha256"].hexdigest(), pulp_domain=get_domain_pk()
                 )
                 if not artifact.pulp_domain.get_storage().exists(artifact.file.name):
                     artifact.file = file
                     artifact.save()
                 else:
                     artifact.touch()
             except (Artifact.DoesNotExist, DatabaseError):
-                artifact_data = {"file": file}
-                serializer = ArtifactSerializer(data=artifact_data)
-                serializer.is_valid(raise_exception=True)
-                artifact = serializer.save()
+                artifact = Artifact.init_and_validate(file)
+                try:
+                    artifact.save()
+                except IntegrityError:
+                    artifact = Artifact.objects.get(
+                        sha256=artifact.sha256, pulp_domain=get_domain_pk()
+                    )
             data["artifact"] = artifact
         return data