feat: add filter on participant

README.md

@@ -38,6 +38,8 @@ On your GitLab repository, follow these steps to add a new webhook:
 4. Fill out the form with the following details:
 
    * **URL**: https://hostname-of-this-api.example.org/api/v1/gitlab-webhook
+     * Since v0.12.0, you can specify a filter to publish notifications only if certain users are involved as the opener, reviewers, or assignees. \
+       Use query parameters `filter_on_participant_ids` with a comma-separated list of user IDs (integers).
    * **Add custom header**:
      * name: `X-Conversation-Token`
      * value: comma separated list of conversation tokens you want the MR messages sent to

app.py

@@ -92,6 +92,7 @@ async def handle_webhook(
     payload: MergeRequestPayload | PipelinePayload | EmojiPayload,
     x_conversation_token: Annotated[str, Header()],
     x_gitlab_token: Annotated[str, Header()],
+    filter_on_participant_ids: str | None = None,
 ):
     validate_gitlab_token(x_gitlab_token)
     conversation_tokens = list(
@@ -100,9 +101,20 @@ async def handle_webhook(
             [validate_uuid(ct.strip()) for ct in x_conversation_token.split(",")],
         )
     )
+
     try:
         if isinstance(payload, MergeRequestPayload):
-            await webhook.merge_request(payload, conversation_tokens)
+            participant_ids_filter: list[int] = []
+            if filter_on_participant_ids:
+                try:
+                    participant_ids_filter = [int(entry) for entry in filter_on_participant_ids.split(",")]
+                except ValueError:
+                    raise HTTPException(
+                        status_code=400,
+                        detail="filter_on_participant_ids must be a list of comma separated integers",
+                    )
+
+            await webhook.merge_request(payload, conversation_tokens, participant_ids_filter)
         if isinstance(payload, PipelinePayload):
             await webhook.pipeline(payload, conversation_tokens)
         if isinstance(payload, EmojiPayload):

webhook/merge_request.py

@@ -134,13 +134,26 @@ async def create_or_update_message(
 async def merge_request(
     mr: MergeRequestPayload,
     conversation_tokens: list[str],
+    participant_ids_filter: list[int],
 ):
     mri = await dbh.get_merge_request_ref_infos(mr)
     convtoken_to_msgrefs = await get_or_create_message_refs(
         mri.merge_request_ref_id,
         conversation_tokens,
     )
 
+    participant_found = True
+    if participant_ids_filter:
+        participant_found = False
+        participant_found |= mri.merge_request_extra_state.opener.id in participant_ids_filter
+        participant_found |= any(
+            [
+                user.id in participant_ids_filter
+                for userlist in (mri.merge_request_payload.assignees, mri.merge_request_payload.reviewers)
+                for user in userlist
+            ]
+        )
+
     connection: asyncpg.Connection
 
     if mr.object_attributes.action in ("update"):
@@ -196,7 +209,8 @@ async def merge_request(
                         "merged",
                     )
                     or mr.object_attributes.draft
-                    or mr.object_attributes.work_in_progress,
+                    or mr.object_attributes.work_in_progress
+                    or not participant_found,
                 )
 
     if mr.object_attributes.action in ("merge", "close") or mr.object_attributes.state in (