mindgamesnl socketio proxy

upstream socketio {
    ip_hash;
    server localhost:8080;
}

server {

    # ...

    location /socket.io/ {
        if ($request_method = OPTIONS) {
                add_header Content-Length 0;
                add_header Content-Type text/plain;
                add_header Access-Control-Allow-Origin "$http_origin" always;
                add_header Access-Control-Allow-Credentials 'true' always;
                add_header Access-Control-Allow-Methods "POST,GET,OPTIONS";
                add_header Access-Control-Allow-Headers "content-type";
                return 204;
        }
        proxy_pass http://socketio;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header Host $host;
        add_header Access-Control-Allow-Origin "$http_origin" always;
        add_header Access-Control-Allow-Credentials 'true' always;
    }
}