Nginx Reverse Proxy +HTTPS with Graylog 3.0 on subdirectory (e.g., server.com/graylog)

@jan, was this updated yet?

I have the reverse proxy working, to a small degree. This Nginx config will load Graylog, and I can login via https://log.internal.mydomain.com.

server {
  listen 443 ssl http2;
  server_name log.internal.mydomain.com;

  #SSL/TLS settings
  ssl_certificate /etc/letsencrypt/live/internal.mydomain.com/fullchain.pem;
  ssl_certificate_key /etc/letsencrypt/live/internal.mydomain.com/privkey.pem;

  location / {
    proxy_pass         http://10.10.2.29:9000/;
    proxy_set_header   Host                  $host;
    proxy_set_header   X-Real-IP             $remote_addr;
    proxy_set_header   X-Forwarded-For       $proxy_add_x_forwarded_for;
    proxy_set_header   X-Forwarded-Host      $host;
    proxy_set_header   X-Forwarded-Server    $host;
    proxy_set_header   X-Graylog-Server-URL  https://$server_name/;
  }
}

However, I cannot change anything, like re-arrange dashboards. This is the error I receive.
error

I can still login to Graylog without HTTPS (on http://10.10.2.29:9000) and make edits as needed.

The applicable settings from my server.conf file are as follows:

http_bind_address = 0.0.0.0:9000
trusted_proxies = 10.10.2.1/32