Just watch out when using oauth2-proxy because its default session storage using cookies can easily blow out the header size of nginx leading to the dreaded 400 header too large

One fix is moving session storage to redis <https://oauth2-proxy.github.io/oauth2-proxy/configuration/se...> and the other (if you have control over the nginx config) is bumping its allowed header size "large_client_header_buffers 4 128k;" <https://nginx.org/en/docs/http/ngx_http_core_module.html#lar...>

If you're using nginx as an ingress controller, the annotations support it: <https://kubernetes.github.io/ingress-nginx/user-guide/nginx-...> and/or auth-snippet <https://kubernetes.github.io/ingress-nginx/user-guide/nginx-...>