Adding python logging to FastApi endpoints, hosted on docker doesn't display API Endpoints logs - python-3.x

Question

I have a fastapi app on which I want to add python logging. I followed the basic tutorial and added this, however this doesn't add API but just gunicorn logging.
So I have a local server hosted using docker build so running server using docker-compose up and testing my endpoints using api client (Insomnia, similar to postman).
Below is the code where no log file is created and hence no log statements added.
My project str is as follows:
project/
src/
api/
models/
users.py
routers/
users.py
main.py
logging.conf
"""
main.py Main is the starting point for the app.
"""
import logging
import logging.config
from fastapi import FastAPI
from msgpack_asgi import MessagePackMiddleware
import uvicorn
from api.routers import users
logger = logging.getLogger(__name__)
app = FastAPI(debug=True)
app.include_router(users.router)
#app.get("/check")
async def check():
"""Simple health check endpoint."""
logger.info("logging from the root logger")
return {"success": True}
Also, I am using gunicorn.conf that looks like this:
[program:gunicorn]
command=poetry run gunicorn -c /etc/gunicorn/gunicorn.conf.py foodgame_api.main:app
directory=/var/www/
autostart=true
autorestart=true
redirect_stderr=true
And gunicorn.conf.py as
import multiprocessing
bind = "unix:/tmp/gunicorn.sock"
workers = multiprocessing.cpu_count() * 2 + 1
worker_class = "uvicorn.workers.UvicornWorker"
loglevel = "debug"
errorlog = "-"
capture_output = True
chdir = "/var/www"
reload = True
reload_engine = "auto"
accesslog = "-"
access_log_format = '%(h)s %(l)s %(u)s %(t)s "%(r)s" %(s)s %(b)s "%(f)s" "%(a)s"'
This is my output terminal for the above API endpoint on docker:
Could anyone please guide me here? I am new to FastApi so some help will be appreciated.

Answer 1

Inspired by #JPG's answer, but using a pydantic model looked cleaner.
You might want to expose more variables. This config worked good for me.
from pydantic import BaseModel
class LogConfig(BaseModel):
"""Logging configuration to be set for the server"""
LOGGER_NAME: str = "mycoolapp"
LOG_FORMAT: str = "%(levelprefix)s | %(asctime)s | %(message)s"
LOG_LEVEL: str = "DEBUG"
# Logging config
version = 1
disable_existing_loggers = False
formatters = {
"default": {
"()": "uvicorn.logging.DefaultFormatter",
"fmt": LOG_FORMAT,
"datefmt": "%Y-%m-%d %H:%M:%S",
},
}
handlers = {
"default": {
"formatter": "default",
"class": "logging.StreamHandler",
"stream": "ext://sys.stderr",
},
}
loggers = {
LOGGER_NAME: {"handlers": ["default"], "level": LOG_LEVEL},
}
Then import it into your main.py file as:
from logging.config import dictConfig
import logging
from .config import LogConfig
dictConfig(LogConfig().dict())
logger = logging.getLogger("mycoolapp")
logger.info("Dummy Info")
logger.error("Dummy Error")
logger.debug("Dummy Debug")
logger.warning("Dummy Warning")
Which gives:

Answer 2

I would use dict log config
create a logger config as below,
# my_log_conf.py
log_config = {
"version": 1,
"disable_existing_loggers": False,
"formatters": {
"default": {
"()": "uvicorn.logging.DefaultFormatter",
"fmt": "%(levelprefix)s %(asctime)s %(message)s",
"datefmt": "%Y-%m-%d %H:%M:%S",
},
},
"handlers": {
"default": {
"formatter": "default",
"class": "logging.StreamHandler",
"stream": "ext://sys.stderr",
},
},
"loggers": {
"foo-logger": {"handlers": ["default"], "level": "DEBUG"},
},
}
Then, load the config using dictConfig function as,
from logging.config import dictConfig
from fastapi import FastAPI
from some.where.my_log_conf import log_config
dictConfig(log_config)
app = FastAPI(debug=True)
Note: It is recommended to call the dictConfig(...) function before the FastAPI initialization.
After the initialization, you can use logger named foo-logger anywhere in your code as,
import logging
logger = logging.getLogger('foo-logger')
logger.debug('This is test')