Add OasstError exception class and exception filter

backend/main.py

@@ -7,10 +7,20 @@ import fastapi
 from loguru import logger
 from oasst_backend.api.v1.api import api_router
 from oasst_backend.config import settings
+from oasst_backend.exceptions import OasstError
 from starlette.middleware.cors import CORSMiddleware
 
 app = fastapi.FastAPI(title=settings.PROJECT_NAME, openapi_url=f"{settings.API_V1_STR}/openapi.json")
 
+
+@app.exception_handler(OasstError)
+async def http_exception_handler(request: fastapi.Request, ex: OasstError):
+    logger.error(f"{request.method} {request.url} failed: {repr(ex)}")
+    return fastapi.responses.JSONResponse(
+        status_code=ex.http_status_code, content={"message": ex.message, "error_code": ex.error_code}
+    )
+
+
 # Set all CORS enabled origins
 if settings.BACKEND_CORS_ORIGINS:
     app.add_middleware(

backend/oasst_backend/api/deps.py

@@ -3,11 +3,12 @@ from secrets import token_hex
 from typing import Generator
 from uuid import UUID
 
-from fastapi import HTTPException, Security
+from fastapi import Security
 from fastapi.security.api_key import APIKey, APIKeyHeader, APIKeyQuery
 from loguru import logger
 from oasst_backend.config import settings
 from oasst_backend.database import engine
+from oasst_backend.exceptions import OasstError, error_codes
 from oasst_backend.models import ApiClient
 from sqlmodel import Session
 from starlette.status import HTTP_403_FORBIDDEN
@@ -36,9 +37,12 @@ def api_auth(
     api_key: APIKey,
     db: Session,
 ) -> ApiClient:
-
     if api_key is None and not settings.DEBUG_SKIP_API_KEY_CHECK:
-        raise HTTPException(status_code=HTTP_403_FORBIDDEN, detail="Could not validate credentials")
+        raise OasstError(
+            "Could not validate credentials",
+            error_code=error_codes.API_CLIENT_NOT_AUTHORIZED,
+            http_status_code=HTTP_403_FORBIDDEN,
+        )
 
     if settings.DEBUG_SKIP_API_KEY_CHECK or settings.DEBUG_ALLOW_ANY_API_KEY:
         # make sure that a dummy api key exits in db (foreign key references)

backend/oasst_backend/api/v1/tasks.py

@@ -3,14 +3,14 @@ import random
 from typing import Any
 from uuid import UUID
 
-from fastapi import APIRouter, Depends, HTTPException
+from fastapi import APIRouter, Depends
 from fastapi.security.api_key import APIKey
 from loguru import logger
 from oasst_backend.api import deps
+from oasst_backend.exceptions import OasstError, error_codes
 from oasst_backend.prompt_repository import PromptRepository
 from oasst_shared.schemas import protocol as protocol_schema
 from sqlmodel import Session
-from starlette.status import HTTP_400_BAD_REQUEST
 
 router = APIRouter()
 
@@ -114,10 +114,7 @@ def generate_task(request: protocol_schema.TaskRequest) -> protocol_schema.Task:
                 ],
             )
         case _:
-            raise HTTPException(
+            raise OasstError("Invalid request type", error_codes.TASK_INVALID_REQUEST_TYPE)
-                status_code=HTTP_400_BAD_REQUEST,
-                detail="Invalid request type.",
-            )
 
     logger.info(f"Generated {task=}.")
 
@@ -134,6 +131,7 @@ def request_task(
     """
     Create new task.
     """
+
     api_client = deps.api_auth(api_key, db)
 
     try:
@@ -142,11 +140,11 @@ def request_task(
         pr = PromptRepository(db, api_client, request.user)
         pr.store_task(task)
 
+    except OasstError:
+        raise
     except Exception:
-        logger.exception("Failed to generate task.")
+        logger.exception("Failed to generate task..")
-        raise HTTPException(
+        raise OasstError("Failed to generate task.", error_codes.TASK_GENERATION_FAILED)
-            status_code=HTTP_400_BAD_REQUEST,
-        )
     return task
 
 
@@ -171,11 +169,11 @@ def acknowledge_task(
         logger.info(f"Frontend acknowledges task {task_id=}, {ack_request=}.")
         pr.bind_frontend_post_id(task_id=task_id, post_id=ack_request.post_id)
 
+    except OasstError:
+        raise
     except Exception:
         logger.exception("Failed to acknowledge task.")
-        raise HTTPException(
+        raise OasstError("Failed to acknowledge task.", error_codes.TASK_ACK_FAILED)
-            status_code=HTTP_400_BAD_REQUEST,
-        )
     return {}
 
 
@@ -242,13 +240,9 @@ def post_interaction(
                 # here we would store the ranking in the database
                 return protocol_schema.TaskDone()
             case _:
-                raise HTTPException(
+                raise OasstError("Invalid response type.", error_codes.TASK_INVALID_RESPONSE_TYPE)
-                    status_code=HTTP_400_BAD_REQUEST,
+    except OasstError:
-                    detail="Invalid response type.",
+        raise
-                )
-
     except Exception:
         logger.exception("Interaction request failed.")
-        raise HTTPException(
+        raise OasstError("Interaction request failed.", error_codes.TASK_INTERACTION_REQUEST_FAILED)
-            status_code=HTTP_400_BAD_REQUEST,
-        )

backend/oasst_backend/database.py

@@ -1,8 +1,9 @@
 # -*- coding: utf-8 -*-
 from oasst_backend.config import settings
+from oasst_backend.exceptions import OasstError, error_codes
 from sqlmodel import create_engine
 
 if settings.DATABASE_URI is None:
-    raise ValueError("DATABASE_URI is not set")
+    raise OasstError("DATABASE_URI is not set", error_code=error_codes.DATABASE_URI_NOT_SET)
 
 engine = create_engine(settings.DATABASE_URI)

backend/oasst_backend/error_codes.py

@@ -0,0 +1,26 @@
+# -*- coding: utf-8 -*-
+"""
+Open-Assistant backend API error codes.
+"""
+# 0-1000: general errors
+GENERIC_ERROR = 0
+DATABASE_URI_NOT_SET = 1
+API_CLIENT_NOT_AUTHORIZED = 2
+
+# 1000-2000: tasks endpoint
+TASK_INVALID_REQUEST_TYPE = 1000
+TASK_ACK_FAILED = 1001
+TASK_INVALID_RESPONSE_TYPE = 1002
+TASK_INTERACTION_REQUEST_FAILED = 1003
+TASK_GENERATION_FAILED = 1004
+
+# 2000-3000: prompt_repository
+INVALID_POST_ID = 2000
+POST_NOT_FOUND = 2001
+RATING_OUT_OF_RANGE = 2002
+INVALID_RANKING_VALUE = 2003
+WORK_PACKAGE_NOT_FOUND = 2004
+WORK_PACKAGE_EXPIRED = 2005
+WORK_PACKAGE_PAYLOAD_TYPE_MISMATCH = 2006
+INVALID_TASK_TYPE = 2007
+USER_NOT_SPECIFIED = 2008

backend/oasst_backend/exceptions.py

@@ -0,0 +1,21 @@
+# -*- coding: utf-8 -*-
+import oasst_backend.error_codes as error_codes  # noqa: F401
+from starlette.status import HTTP_400_BAD_REQUEST
+
+
+class OasstError(Exception):
+    """Base class for Open-Assistant exceptions."""
+
+    message: str
+    error_code: int
+    http_status_code: int
+
+    def __init__(self, message: str, error_code: int, http_status_code: int = HTTP_400_BAD_REQUEST):
+        super().__init__(message, error_code, http_status_code)  # make excetpion picklable (fill args member)
+        self.message = message
+        self.error_code = error_code
+        self.http_status_code = http_status_code
+
+    def __repr__(self) -> str:
+        class_name = self.__class__.__name__
+        return f'{class_name}(message="{self.message}", error_code={self.error_code}, http_status_code={self.http_status_code})'

backend/oasst_backend/prompt_repository.py

@@ -5,6 +5,7 @@ from uuid import UUID, uuid4
 
 import oasst_backend.models.db_payload as db_payload
 from loguru import logger
+from oasst_backend.exceptions import OasstError, error_codes
 from oasst_backend.journal_writer import JournalWriter
 from oasst_backend.models import ApiClient, Person, Post, PostReaction, TextLabels, WorkPackage
 from oasst_backend.models.payload_column_type import PayloadContainer
@@ -52,9 +53,9 @@ class PromptRepository:
 
     def validate_post_id(self, post_id: str) -> None:
         if not isinstance(post_id, str):
-            raise TypeError(f"post_id must be string, not {type(post_id)}")
+            raise OasstError(f"post_id must be string, not {type(post_id)}", error_codes.INVALID_POST_ID)
         if not post_id:
-            raise ValueError("post_id must not be empty")
+            raise OasstError("post_id must not be empty", error_codes.INVALID_POST_ID)
 
     def bind_frontend_post_id(self, task_id: UUID, post_id: str):
         self.validate_post_id(post_id)
@@ -66,9 +67,9 @@ class PromptRepository:
             .first()
         )
         if work_pack is None:
-            raise KeyError(f"WorkPackage for task {task_id} not found")
+            raise OasstError(f"WorkPackage for task {task_id} not found", error_codes.WORK_PACKAGE_NOT_FOUND)
         if work_pack.expiry_date is not None and datetime.utcnow() > work_pack.expiry_date:
-            raise RuntimeError("WorkPackage already expired.")
+            raise OasstError("WorkPackage already expired.", error_codes.WORK_PACKAGE_EXPIRED)
 
         # ToDo: check race-condition, transaction
 
@@ -105,7 +106,7 @@ class PromptRepository:
             .one_or_none()
         )
         if fail_if_missing and post is None:
-            raise KeyError(f"Post with post_id {frontend_post_id} not found.")
+            raise OasstError(f"Post with post_id {frontend_post_id} not found.", error_codes.POST_NOT_FOUND)
         return post
 
     def fetch_workpackage_by_postid(self, post_id: str) -> WorkPackage:
@@ -134,7 +135,7 @@ class PromptRepository:
         )
 
         if parent_post is None:
-            raise KeyError(f"Post for post_id {reply.post_id} not found.")
+            raise OasstError(f"Post for post_id {reply.post_id} not found.", error_codes.POST_NOT_FOUND)
 
         # create reply post
         user_post_id = uuid4()
@@ -156,12 +157,15 @@ class PromptRepository:
         work_package = self.fetch_workpackage_by_postid(rating.post_id)
         work_payload: db_payload.RateSummaryPayload = work_package.payload.payload
         if type(work_payload) != db_payload.RateSummaryPayload:
-            raise ValueError(
+            raise OasstError(
-                f"work_package payload type mismatch: {type(work_payload)=} != {db_payload.RateSummaryPayload}"
+                f"work_package payload type mismatch: {type(work_payload)=} != {db_payload.RateSummaryPayload}",
+                error_codes.WORK_PACKAGE_PAYLOAD_TYPE_MISMATCH,
             )
 
         if rating.rating < work_payload.scale.min or rating.rating > work_payload.scale.max:
-            raise ValueError(f"Invalid rating value: {rating.rating=} not in {work_payload.scale=}")
+            raise OasstError(
+                f"Invalid rating value: {rating.rating=} not in {work_payload.scale=}", error_codes.RATING_OUT_OF_RANGE
+            )
 
         # store reaction to post
         reaction_payload = db_payload.RatingReactionPayload(rating=rating.rating)
@@ -185,8 +189,9 @@ class PromptRepository:
                 # validate ranking
                 num_replies = len(work_payload.replies)
                 if sorted(ranking.ranking) != list(range(num_replies)):
-                    raise ValueError(
+                    raise OasstError(
-                        f"Invalid ranking submitted. Each reply index must appear exactly once ({num_replies=})."
+                        f"Invalid ranking submitted. Each reply index must appear exactly once ({num_replies=}).",
+                        error_codes.INVALID_RANKING_VALUE,
                     )
 
                 # store reaction to post
@@ -201,8 +206,9 @@ class PromptRepository:
             case db_payload.RankInitialPromptsPayload:
                 # validate ranking
                 if sorted(ranking.ranking) != list(range(num_prompts := len(work_payload.prompts))):
-                    raise ValueError(
+                    raise OasstError(
-                        f"Invalid ranking submitted. Each reply index must appear exactly once ({num_prompts=})."
+                        f"Invalid ranking submitted. Each reply index must appear exactly once ({num_prompts=}).",
+                        error_codes.INVALID_RANKING_VALUE,
                     )
 
                 # store reaction to post
@@ -215,8 +221,9 @@ class PromptRepository:
                 return reaction
 
             case _:
-                raise ValueError(
+                raise OasstError(
-                    f"work_package payload type mismatch: {type(work_payload)=} != {db_payload.RankConversationRepliesPayload}"
+                    f"work_package payload type mismatch: {type(work_payload)=} != {db_payload.RankConversationRepliesPayload}",
+                    error_codes.WORK_PACKAGE_PAYLOAD_TYPE_MISMATCH,
                 )
 
     def store_task(self, task: protocol_schema.Task) -> WorkPackage:
@@ -253,7 +260,7 @@ class PromptRepository:
                 )
 
             case _:
-                raise ValueError(f"Invalid task type: {type(task)=}")
+                raise OasstError(f"Invalid task type: {type(task)=}", error_codes.INVALID_TASK_TYPE)
 
         wp = self.insert_work_package(payload=payload, id=task.id)
         assert wp.id == task.id
@@ -310,7 +317,7 @@ class PromptRepository:
 
     def insert_reaction(self, post_id: UUID, payload: db_payload.ReactionPayload) -> PostReaction:
         if self.person_id is None:
-            raise ValueError("User required")
+            raise OasstError("User required", error_codes.USER_NOT_SPECIFIED)
 
         container = PayloadContainer(payload=payload)
         reaction = PostReaction(