FastAPI MiddleWare Logger

This library is a very simple tool to simplify custom formatting of logs for FastAPI. It's almost entirely based on this answer from SO.

Usage

The design of this library is made to be very simple to use. Instead of instantiating FastAPI, just instatiate FastAPIMiddleWareLogger:

from fastapi_middleware_logger.fastapi_middleware_logger import add_custom_logger
from fastapi_middleware_logger import FastAPIMiddleWareLogger
import logging
from fastapi import FastAPI


logging.basicConfig(level=logging.INFO)


app = FastAPIMiddleWareLogger()
# app = FastAPI()
# app = add_custom_logger(app)


@app.get("/")
def get_index():
    return {"status": "ok"}


@app.get("/error")
def get_error():
    raise TypeError("Some error happened !")

Another way to add custom loggers is to use add_custom_logger.

Custom logger

If the request is handled properly, the custom_logger will be called. The custom_logger can take the following arguments:

• request_body: body of the request as a string
• request_headers: headers of the request as a dictionary
• request_query_params: query parameters of the request as a dictionary
• request_method: method of the request as a string
• request_url: URL of the request as a string
• response_body: body of the response as a string
• response_headers: headers of the response as a dictionary
• response_media_type: media type of the response as a string
• response_status_code: status code of the response as an integer

By default, the custom_logger will print out all of these arguments.

Custom error logger

If the request throws an exception, the custom_error_logger will be called. The custom_error_logger can take the following arguments:

• request_body: body of the request as a string
• request_headers: headers of the request as a dictionary
• request_query_params: query parameters of the request as a dictionary
• request_method: method of the request as a string
• request_url: URL of the request as a string
• error_message: message of the exception as a string

Usual uvicorn/fastapi logs can be kept by using disable_uvicorn_logging=False. This could be used to perform other operations but I have not, nor will, tested it.