The apiserver rejects the email username-claim when email_verified is false
(invalid bearer token 401). Authentik external/social users are unverified,
so the default scope-email mapping fails. Mirror the proven kubernetes
provider: use the custom 'Kubernetes Email (verified)' mapping (hardcodes
email_verified=true) + 'Kubernetes Groups'. Drop the now-unneeded dual-aud
mapping (apiserver trusts the k8s-dashboard issuer w/ audience=client_id) and
align oauth2-proxy scope to 'openid email profile groups'.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Provider had signing_key=null → Authentik signed id_tokens with HS256 and
served an empty JWKS, so oauth2-proxy (and the apiserver) failed signature
verification (500 'failed to verify id token signature' on the callback).
Use the same 'authentik Self-signed Certificate' keypair the kubernetes
provider uses.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The Authentik group policy denied admins: it gated on kubernetes-* group
membership, but cluster access is email-based RBAC (User bindings from
k8s_users), not group-based. vbarzin@gmail.com (Home Server Admins) gets
cluster-admin via oidc-admin-vbarzin but isn't in any kubernetes-* group,
so the gate locked him out. Apiserver RBAC is now the sole gate — matching
the kubelogin CLI (authenticate freely, RBAC decides actions).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
