Use structlog and enable persisting logs in JSONL format

.gitignore

@@ -53,7 +53,7 @@ package-lock.json
 *.temp
 
 # Log files
-*.log
+*.log*
 logs/
 npm-debug.log*
 yarn-debug.log*

Dockerfile

@@ -45,4 +45,4 @@ COPY ./backend .
 # Copy the frontend build
 COPY --from=builder /frontend/dist ./ui
 
-ENTRYPOINT [ "uvicorn", "app.server:app", "--host", "0.0.0.0" ]
+ENTRYPOINT [ "uvicorn", "app.server:app", "--host", "0.0.0.0", "--log-config", "log_config.json" ]

backend/Dockerfile

@@ -29,4 +29,4 @@ COPY . .
 
 HEALTHCHECK --interval=30s --timeout=5s --start-period=10s --start-interval=1s --retries=3 CMD [ "curl", "-f", "http://localhost:8000/health" ]
 
-ENTRYPOINT [ "uvicorn", "app.server:app", "--host", "0.0.0.0" ]
+ENTRYPOINT [ "uvicorn", "app.server:app", "--host", "0.0.0.0", "--log-config", "log_config.json" ]

backend/Makefile

@@ -14,7 +14,7 @@ build_ui:
 TEST_FILE ?= tests/unit_tests/
 
 start:
-	poetry run uvicorn app.server:app --reload --port 8100
+	poetry run uvicorn app.server:app --reload --port 8100 --log-config log_config.json
 
 migrate:
 	migrate -database postgres://$(POSTGRES_USER):$(POSTGRES_PASSWORD)@$(POSTGRES_HOST):$(POSTGRES_PORT)/$(POSTGRES_DB)?sslmode=disable -path ./migrations up

backend/app/lifespan.py

@@ -3,6 +3,7 @@
 
 import asyncpg
 import orjson
+import structlog
 from fastapi import FastAPI
 
 _pg_pool = None
@@ -26,6 +27,23 @@ async def _init_connection(conn) -> None:
 
 @asynccontextmanager
 async def lifespan(app: FastAPI):
+    structlog.configure(
+        processors=[
+            structlog.stdlib.filter_by_level,
+            structlog.stdlib.add_logger_name,
+            structlog.stdlib.add_log_level,
+            structlog.stdlib.PositionalArgumentsFormatter(),
+            structlog.processors.TimeStamper(fmt="iso"),
+            structlog.processors.StackInfoRenderer(),
+            structlog.processors.format_exc_info,
+            structlog.processors.UnicodeDecoder(),
+            structlog.stdlib.render_to_log_kwargs,
+        ],
+        logger_factory=structlog.stdlib.LoggerFactory(),
+        wrapper_class=structlog.stdlib.BoundLogger,
+        cache_logger_on_first_use=True,
+    )
+
     global _pg_pool
 
     _pg_pool = await asyncpg.create_pool(

backend/app/llms.py

@@ -1,17 +1,17 @@
-import logging
 import os
 from functools import lru_cache
 from urllib.parse import urlparse
 
 import boto3
 import httpx
+import structlog
 from langchain_anthropic import ChatAnthropic
 from langchain_community.chat_models import BedrockChat, ChatFireworks
 from langchain_community.chat_models.ollama import ChatOllama
 from langchain_google_vertexai import ChatVertexAI
 from langchain_openai import AzureChatOpenAI, ChatOpenAI
 
-logger = logging.getLogger(__name__)
+logger = structlog.get_logger(__name__)
 
 
 @lru_cache(maxsize=4)

backend/app/server.py

@@ -1,8 +1,8 @@
-import logging
 import os
 from pathlib import Path
 
 import orjson
+import structlog
 from fastapi import FastAPI, Form, UploadFile
 from fastapi.exceptions import HTTPException
 from fastapi.staticfiles import StaticFiles
@@ -13,7 +13,7 @@
 from app.lifespan import lifespan
 from app.upload import convert_ingestion_input_to_blob, ingest_runnable
 
-logger = logging.getLogger(__name__)
+logger = structlog.get_logger(__name__)
 
 app = FastAPI(title="OpenGPTs API", lifespan=lifespan)
 

backend/app/stream.py

@@ -1,12 +1,12 @@
-import logging
 from typing import Any, AsyncIterator, Dict, Optional, Sequence, Union
 
 import orjson
+import structlog
 from langchain_core.messages import AnyMessage, BaseMessage, message_chunk_to_message
 from langchain_core.runnables import Runnable, RunnableConfig
 from langserve.serialization import WellKnownLCSerializer
 
-logger = logging.getLogger(__name__)
+logger = structlog.get_logger(__name__)
 
 MessagesStream = AsyncIterator[Union[list[AnyMessage], str]]
 

backend/log_config.json

@@ -0,0 +1,70 @@
+{
+    "version": 1,
+    "disable_existing_loggers": false,
+    "formatters": {
+        "default": {
+            "()": "uvicorn.logging.DefaultFormatter",
+            "fmt": "%(asctime)s - %(name)s - %(levelprefix)s %(message)s"
+        },
+        "access": {
+            "()": "uvicorn.logging.AccessFormatter",
+            "fmt": "%(asctime)s - %(name)s - %(levelprefix)s  %(client_addr)s - \"%(request_line)s\" %(status_code)s"
+        },
+        "json": {
+            "()": "pythonjsonlogger.jsonlogger.JsonFormatter"
+        }
+    },
+    "handlers": {
+        "default": {
+            "formatter": "default",
+            "class": "logging.StreamHandler",
+            "stream": "ext://sys.stderr"
+        },
+        "access": {
+            "formatter": "access",
+            "class": "logging.StreamHandler",
+            "stream": "ext://sys.stdout"
+        },
+        "file": {
+            "formatter": "json",
+            "class": "logging.handlers.RotatingFileHandler",
+            "filename": "./app.log",
+            "mode": "a+",
+            "maxBytes": 10000000,
+            "backupCount": 1
+        }
+    },
+    "root": {
+        "handlers": [
+            "default",
+            "file"
+        ],
+        "level": "INFO"
+    },
+    "loggers": {
+        "app": {
+            "handlers": [
+                "default",
+                "file"
+            ],
+            "level": "INFO",
+            "propagate": false
+        },
+        "uvicorn": {
+            "handlers": [
+                "default",
+                "file"
+            ],
+            "level": "INFO",
+            "propagate": false
+        },
+        "uvicorn.access": {
+            "handlers": [
+                "access",
+                "file"
+            ],
+            "level": "INFO",
+            "propagate": false
+        }
+    }
+}

backend/pyproject.toml

@@ -43,6 +43,8 @@ asyncpg = "^0.29.0"
 langchain-core = "^0.1.44"
 pyjwt = {extras = ["crypto"], version = "^2.8.0"}
 langchain-anthropic = "^0.1.8"
+structlog = "^24.1.0"
+python-json-logger = "^2.0.7"
 
 [tool.poetry.group.dev.dependencies]
 uvicorn = "^0.23.2"