[Bug] authURL is empty when using GitHub as an OIDC server #2168

Is this a support request?

• This is not a support request

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

Headscale redirects to empty authURL

2024-10-03T11:08:53Z DBG Redirecting to ?client_id=123&domain_hint=...

Expected Behavior

Headscale should redirect to "https://github.com/login/oauth/authorize"

Steps To Reproduce

1. Create an OAuth app in GitHub developer settings
2. Set up Headscale to use GitHub as an OIDC server:

oidc:
  only_start_if_oidc_is_available: true
  issuer: "https://token.actions.githubusercontent.com"
  client_id: "123"
  client_secret: "123"

3. Try to login

Environment

- OS: Ubuntu 24.04
- Headscale version: 0.23.0

Runtime environment

• Headscale is behind a (reverse) proxy
• Headscale runs in a container

Anything else?

No response