server {
    listen       ${LISTEN_PORT};
    server_name  _;

    resolver 127.0.0.11 valid=1s;

    location / {
        proxy_pass http://${CONTAINER_PREFIX}-$http_x_forwarded_preferred_username:${CONTAINER_PORT}$uri;
        error_page 502 = @spawner;
    }
    
    location @spawner {
        proxy_pass ${SPAWNER_URL}$uri;
    }
}