Best practices for handling OAuth2 token refresh in a Python 3.x backend for frontend integrations
I'm writing unit tests and I'm getting frustrated with Working on a project where our frontend application relies heavily on third-party services, I've been tasked with managing OAuth2 tokens for API integrations. The challenge is to ensure that access tokens are refreshed seamlessly without causing interruptions for users. Initially, I set up a basic implementation using the `requests` library and a simple token flow: ```python import requests CLIENT_ID = 'your_client_id' CLIENT_SECRET = 'your_client_secret' TOKEN_URL = 'https://provider.com/oauth/token' def get_access_token(): response = requests.post(TOKEN_URL, data={ 'grant_type': 'client_credentials', 'client_id': CLIENT_ID, 'client_secret': CLIENT_SECRET, }) token_data = response.json() return token_data['access_token'] ``` This function works well to get the initial token, but I noticed that it doesn't handle the refreshing of expired tokens elegantly. To improve this, I explored the use of decorators to wrap my API calls, fetching a new token when needed. My current implementation looks something like this: ```python def token_required(func): def wrapper(*args, **kwargs): if is_token_expired(): # Custom function to check token expiry refresh_token() # Function to refresh the token return func(*args, **kwargs) return wrapper ``` However, I’m struggling with properly handling concurrent requests that may trigger token refresh at the same time. I’ve considered using threading or asyncio, but I’m not sure how best to implement that given our app's architecture. I've read that using a lock mechanism could prevent race conditions, but I'm not confident about the best way to achieve that in this scenario. Any insights on strategies or patterns that can help manage the refresh token process while ensuring a smooth user experience? Are there specific libraries or frameworks that might facilitate this integration in a more robust manner? I'm using Python stable in this project. What's the correct way to implement this? This is my first time working with Python latest. Thanks in advance! Any advice would be much appreciated.