Make auto-distribute feature more intuitive

backports: #9039
https://pulp.plan.io/issues/9039

fixes #9059

(cherry picked from commit 2cc9804)

CHANGES/9059.bugfix

@@ -0,0 +1,2 @@
+Fixed the behavior of setting "repository" on a distribution for publication-based plugins.
+(backported from #9039)

pulpcore/app/models/publication.py

@@ -125,13 +125,14 @@ def delete(self, **kwargs):
             Deletes the Task.created_resource when complete is False.
         """
         with transaction.atomic():
+            # invalidate cache
             if settings.CACHE_ENABLED:
                 # Find any publications being served directly
                 base_paths = self.distribution_set.values_list("base_path", flat=True)
                 # Find any publications being served indirectly by auto-distribute feature
                 versions = self.repository.versions.all()
                 pubs = Publication.objects.filter(repository_version__in=versions, complete=True)
-                publication = pubs.latest("repository_version", "-pulp_created")
+                publication = pubs.latest("repository_version", "pulp_created")
                 if self.pk == publication.pk:
                     base_paths |= self.repository.distributions.values_list("base_path", flat=True)
                 # Invalidate cache for all distributions serving this publication
@@ -183,6 +184,14 @@ def __exit__(self, exc_type, exc_val, exc_tb):
                 self.delete()
                 raise
 
+            # invalidate cache
+            if settings.CACHE_ENABLED:
+                base_paths = Distribution.objects.filter(
+                    repository=self.repository_version.repository
+                ).values_list("base_path", flat=True)
+                if base_paths:
+                    Cache().delete(base_key=base_paths)
+
 
 class PublishedArtifact(BaseModel):
     """

pulpcore/content/handler.py

@@ -466,18 +466,24 @@ def check_permit_blocking():
             def get_latest_publication_or_version_blocking():
                 nonlocal repo_version
                 nonlocal publication
-                repo_version = repository.latest_version()
+
                 # Search for publication serving the closest latest version
                 if not publication:
                     try:
                         versions = repository.versions.all()
                         publications = Publication.objects.filter(
                             repository_version__in=versions, complete=True
                         )
-                        publication = publications.latest("repository_version", "-pulp_created")
+                        publication = publications.select_related("repository_version").latest(
+                            "repository_version", "pulp_created"
+                        )
+                        repo_version = publication.repository_version
                     except ObjectDoesNotExist:
                         pass
 
+                if not repo_version:
+                    repo_version = repository.latest_version()
+
             await loop.run_in_executor(None, get_latest_publication_or_version_blocking)
 
         if publication: