.Net Core behind NGINX returns 502 Bad Gateway after authentication by IdentityServer4

The problem has been solved. It seems that NGINX doesn't allow a large header content. From this help https://medium.com/@mshanak/solve-nginx-error-signin-oidc-502-bad-gateway-dotnet-core-and-identity-serve-bc27920b42d5 , we have set these properties:

nginx.conf

http{
...
proxy_buffer_size   128k;
proxy_buffers   4 256k;
proxy_busy_buffers_size   256k;
large_client_header_buffers 4 16k;
...
}

default.conf

location /{
    ...
    fastcgi_buffers 16 16k;
    fastcgi_buffer_size 32k;
    ...
}

Wonder if there is any way to configure IdentityServer to send much smaller header content!

It is also possible to configure this with annotations:

  annotations:
    kubernetes.io/ingress.class: "nginx"    
    nginx.ingress.kubernetes.io/proxy-buffering: "on"
    nginx.ingress.kubernetes.io/proxy-buffer-size: "128k"
    nginx.ingress.kubernetes.io/proxy-buffers-number: "4"

so you can add them to your existing ingress.yaml, for example like that:

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: ingress-production
  namespace: ingress-nginx
  annotations:
    kubernetes.io/ingress.class: "nginx"    
    nginx.ingress.kubernetes.io/proxy-buffering: "on"
    nginx.ingress.kubernetes.io/proxy-buffer-size: "128k"
    nginx.ingress.kubernetes.io/proxy-buffers-number: "4"
    certmanager.k8s.io/issuer: "letsencrypt-production"
spec:
  tls:
  - hosts:
    - example.com
    secretName: example-tls
  rules:
  - host: example.com
    http:
      paths:
      - path: /
        backend:
          serviceName: example-app
          servicePort: 80