Use redis for the discord member cache over mongo

Author: ChrisLovering

backend/authentication/backend.py

@@ -63,7 +63,7 @@ async def authenticate(
         user = User(
             token,
             user_details,
-            await discord.get_member(request.state.db, user_details["id"]),
+            await discord.get_member(user_details["id"]),
         )
         if await user.fetch_admin_status(request.state.db):
             scopes.append("admin")

backend/authentication/user.py

@@ -67,9 +67,9 @@ async def fetch_admin_status(self, database: Database) -> bool:
 
         return self.admin
 
-    async def refresh_data(self, database: Database) -> None:
+    async def refresh_data(self) -> None:
         """Fetches user data from discord, and updates the instance."""
-        self.member = await discord.get_member(database, self.payload["id"])
+        self.member = await discord.get_member(self.payload["id"])
 
         if self.member:
             self.payload = self.member.user.dict()

backend/discord.py

@@ -124,7 +124,6 @@ async def _fetch_member_api(member_id: str) -> models.DiscordMember | None:
 
 
 async def get_member(
-    database: Database,
     user_id: str,
     *,
     force_refresh: bool = False,
@@ -135,34 +134,23 @@ async def get_member(
     If `force_refresh` is True, the cache is skipped and the entry is updated.
     None may be returned if the member object does not exist.
     """
-    collection = database.get_collection("discord_members")
+    member_key = f"forms-backend:member_cache:{user_id}"
 
     if force_refresh:
-        await collection.delete_one({"user": user_id})
-
-    # `create_index` creates the index if it does not exist, or passes
-    # This handles TTL on member objects
-    await collection.create_index(
-        "inserted_at",
-        expireAfterSeconds=60 * 60,  # 1 hour
-        name="inserted_at",
-    )
+        await constants.REDIS_CLIENT.delete(member_key)
 
-    result = await collection.find_one({"user": user_id})
+    result = await constants.REDIS_CLIENT.get(member_key)
 
     if result is not None:
-        return models.DiscordMember(**json.loads(result["data"]))
+        return models.DiscordMember(**json.loads(result))
 
     member = await _fetch_member_api(user_id)
 
     if not member:
         return None
 
-    await collection.insert_one({
-        "user": user_id,
-        "data": member.json(),
-        "inserted_at": datetime.datetime.now(tz=datetime.UTC),
-    })
+    await constants.REDIS_CLIENT.set(member_key, member.json(), ex=60 * 60)
+
     return member
 
 

backend/routes/auth/authorize.py

@@ -44,7 +44,7 @@ async def process_token(
         return AUTH_FAILURE
 
     user_id = user_details["id"]
-    member = await get_member(request.state.db, user_id, force_refresh=True)
+    member = await get_member(user_id, force_refresh=True)
 
     max_age = datetime.timedelta(seconds=int(bearer_token["expires_in"]))
     token_expiry = interaction_start + max_age

backend/routes/discord.py

@@ -60,7 +60,7 @@ class MemberRequest(pydantic.BaseModel):
     async def delete(self, request: Request) -> JSONResponse:
         """Force a resync of the cache for the given user."""
         body = await request.json()
-        member = await discord.get_member(request.state.db, body["user_id"], force_refresh=True)
+        member = await discord.get_member(body["user_id"], force_refresh=True)
 
         if member:
             return JSONResponse(member.dict())
@@ -75,7 +75,7 @@ async def delete(self, request: Request) -> JSONResponse:
     async def get(self, request: Request) -> JSONResponse:
         """Get a user's roles on the configured server."""
         body = await request.json()
-        member = await discord.get_member(request.state.db, body["user_id"])
+        member = await discord.get_member(body["user_id"])
 
         if not member:
             return NOT_FOUND_EXCEPTION

backend/routes/forms/submit.py

@@ -85,7 +85,7 @@ async def post(self, request: Request) -> JSONResponse:
         try:
             if hasattr(request.user, User.refresh_data.__name__):
                 old = request.user.token
-                await request.user.refresh_data(request.state.db)
+                await request.user.refresh_data()
 
                 if old != request.user.token:
                     try: