Integrating OAuth2 for secure API access in a Linux-based microservices architecture
I've searched everywhere and can't find a clear answer. Need to create a secure integration for an existing microservices architecture that handles sensitive user data. The goal is to implement OAuth2 for API access control, ensuring each service can authenticate users securely and consistently. Using a Linux server running Ubuntu 20.04, I’ve set up an API gateway with Kong, which should handle incoming requests and route them to the appropriate microservices. However, I’m struggling with the configuration of the OAuth2 plugin. Here’s what I’ve done so far: 1. **Kong Gateway Configuration**: I’ve installed the OAuth2 plugin with the following command: ```bash kong reload ``` Next, I registered the plugin with: ```bash curl -i -X POST http://localhost:8001/plugins/ -d 'name=oauth2' -d 'config.scopes=email,profile' -d 'config.mandatory_scope=true' -d 'config.enable_client_credentials=true' ``` But I’m not sure how to set up the clients and secrets properly. The official docs mention creating a consumer, but I’m unclear about the exact steps. 2. **Creating a Consumer**: I tried the following command: ```bash curl -i -X POST http://localhost:8001/consumers/ -d 'username=myuser' ``` followed by: ```bash curl -i -X POST http://localhost:8001/consumers/myuser/oauth2 -d 'name=my_client' -d 'client_id=my_client_id' -d 'client_secret=my_client_secret' -d 'redirect_uris[]=http://localhost:3000/callback' ``` This seems to work, but I’m lost on how to validate the tokens on the backend microservices. Should I use JWT for this? What libraries are recommended for token validation in Node.js services? 3. **Service Implementation**: In my Node.js service, I’m using Express. Here’s a snippet of the middleware I’ve started to implement: ```javascript const jwt = require('jsonwebtoken'); const validateToken = (req, res, next) => { const token = req.headers['authorization'] && req.headers['authorization'].split(' ')[1]; if (!token) return res.sendStatus(401); jwt.verify(token, process.env.JWT_SECRET, (err, user) => { if (err) return res.sendStatus(403); req.user = user; next(); }); }; app.use(validateToken); ``` I’ve set the `JWT_SECRET`, but should it be the same as the OAuth2 client secret? And how can I ensure token expiration and refresh properly? Additionally, during testing, I’ve encountered a 403 error when trying to access endpoints, leading me to believe there might be an issue with scopes or token validation. 4. **Debugging Steps**: I’ve checked the Kong logs by using: ```bash tail -f /usr/local/kong/logs/error.log ``` and confirmed the requests are reaching Kong, but the errors seem to point towards the token validation process. All in all, I appreciate any insights on best practices for implementing OAuth2 in a microservice context. Specifically, how to streamline the token creation and validation process across multiple services while preserving security and usability. Thanks! I'd really appreciate any guidance on this.