sag_py_fastapi_request_id

This library provides a way to identify all log entries that belong to a single request.

What it does

• Provides a middleware to generate a random request id for every request
• Contains a logging filter that adds the request id as field to every log entry

How to use

Installation

pip install sag-py-fastapi-request-id

Add the middleware

Add this middleware so that the request ids are generated:

from sag_py_fastapi_request_id.request_context_middleware import RequestContextMiddleware
from fastapi import FastAPI

app = FastAPI(...)
app.add_middleware(RequestContextMiddleware)

Get the request id

The request id can be accessed over the context

from sag_py_fastapi_request_id.request_context import get_request_id as get_request_id_from_context
request_id = get_request_id_from_context()

This works in async calls but not in sub threads (without additional changes).

See:

• https://docs.python.org/3/library/contextvars.html
• https://kobybass.medium.com/python-contextvars-and-multithreading-faa33dbe953d

Add request id field to logging

It is possible to log the request id by adding a filter.

import logging
from sag_py_fastapi_request_id.request_context_logging_filter import RequestContextLoggingFilter

console_handler = logging.StreamHandler(sys.stdout)
console_handler.addFilter(RequestContextLoggingFilter())

The filter adds the field request_id if it has a value in the context.

How to start developing

With vscode

Just install vscode with dev containers extension. All required extensions and configurations are prepared automatically.

With pycharm

• Install latest pycharm
• Install pycharm plugin Mypy
• Configure the python interpreter/venv
• pip install requirements-dev.txt
• Ctl+Alt+S => Click Tools => Actions on save => Reformat code
• Restart pycharm

How to publish

• Update the version in setup.py and commit your change
• Create a tag with the same version number
• Let github do the rest