nginx config

/etc/nginx/nginx.conf

user www-data;
worker_processes  4;

error_log  /var/log/nginx/error.log;
pid        /var/run/nginx.pid;

events {
    worker_connections  1024;
}

http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    access_log  /var/log/nginx/access.log;

    sendfile        on;
    #tcp_nopush     on;

    #keepalive_timeout  0;
    keepalive_timeout  65;
    tcp_nodelay        on;

    gzip  on;
    gzip_types      text/plain text/css application/x-javascript text/xml application/xml application/xml+rss text/javascript;

    include /etc/nginx/sites-enabled/*;
}

Common to apache2 redirection::

location / {
    # For file uploads, set to max upload size:
    client_max_body_size 32M;

    # root   /var/www/nginx-default;
    # index  index.html index.htm;
    proxy_pass http://127.0.0.1:81/;
    proxy_set_header Host $http_host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}