Mirror release version alias writes [RHELDST-28333]

During the RHEL GA process some repos would appear to temporarily
corrupt from the customer's point of view, usually appearing as 404
errors when fetching repodata files. This is due to aliases getting
updated and delay in data being flushed.

This change introduces mirroring writes on both the source and
destination, which will prevent these errors from occuring.

exodus_gw/aws/dynamodb.py

@@ -25,12 +25,14 @@ def __init__(
         from_date: str,
         env_obj: Environment | None = None,
         deadline: datetime | None = None,
+        mirror_writes: bool = False
     ):
         self.env = env
         self.settings = settings
         self.from_date = from_date
         self.env_obj = env_obj or get_environment(env)
         self.deadline = deadline
+        self.mirror_writes = mirror_writes
         self.client = DynamoDBClientWrapper(self.env_obj.aws_profile).client
         self._lock = Lock()
         self._definitions = None
@@ -208,6 +210,14 @@ def query_definitions(self) -> dict[str, Any]:
             out = json.loads(item_json)
         return out
 
+    def should_mirror_write(self, uri):
+        # We only want to mirror writes for release ver aliases. Recalculating
+        # the aliases completely is a bit inefficient, but I'd rather not
+        # duplicate any alias logic.
+        print(self._aliases(["releasever_alias"]))
+        return self.mirror_writes and \
+               uri_alias(uri, self._aliases(["releasever_alias"]))[0] != uri
+
     def create_request(
         self,
         items: list[models.Item],
@@ -255,6 +265,19 @@ def create_request(
                         }
                     }
                 )
+                if self.should_mirror_write(item.web_uri):
+                    request[table_name].append(
+                        {
+                            "PutRequest": {
+                                "Item": {
+                                    "from_date": {"S": from_date},
+                                    "web_uri": {"S": item.web_uri},
+                                    "object_key": {"S": item.object_key},
+                                    "content_type": {"S": item.content_type},
+                                }
+                            }
+                        }
+                    )
         return request
 
     def create_config_request(self, config):

exodus_gw/settings.py

@@ -475,6 +475,10 @@ class Settings(BaseSettings):
     s3_pool_size: int = 3
     """Number of S3 clients to cache"""
 
+    mirror_writes_enabled: bool = True
+    """Whether both the original url and release var alias are written during
+     phase 1 commits."""
+
     model_config = SettingsConfigDict(env_prefix="exodus_gw_")
 
 

exodus_gw/worker/publish.py

@@ -186,9 +186,14 @@ def dynamodb(self):
                 self.from_date,
                 self.env_obj,
                 self.task.deadline,
+                self.should_mirror_writes,
             )
         return self._dynamodb
 
+    @property
+    def should_mirror_writes(self):
+        return False
+
     @property
     def task_ready(self) -> bool:
         task = self.task
@@ -446,6 +451,10 @@ class CommitPhase1(CommitBase):
     # phase1 commit is allowed to proceed in either of these states.
     PUBLISH_STATES = [PublishStates.committing, PublishStates.pending]
 
+    @property
+    def should_mirror_writes(self):
+        return self.settings.mirror_writes_enabled
+
     @property
     def item_select(self):
         # Query for items to be handled by phase1 commit.