I'm using traefik as a reverse proxy. I want to set OAuth2 authentication for a entry point. In the document, I found the Forward Authentication which I think may be useful for this. But the document is just too simple
This configuration will first forward the request to http://authserver.com/auth.
If the response code is 2XX, access is granted and the original request is performed. Otherwise, the response from the authentication server is returned.
I've no idea how can I achieve authentication OAuth2 within a forwarding?
I've tried oauth2_proxy but didn't find a solution.
In this issue/comment guybrush provided a solution. But that, in fact, was a double reverse proxys.
I've recently built an app for this: https://github.com/thomseddon/traefik-forward-auth
It uses Forward Authentication, as you mentioned, and uses Google OAuth to authenticate users.
There's an example Docker Compose setup here: https://github.com/thomseddon/traefik-forward-auth/blob/master/examples/docker-compose.yml. See the traefik.toml file to see how Traefik is configured to point at the app.
Let me know if it is helpful!