Nginx: 502 Bad GateWay

The 502 error appears because nginx cannot hand off to php5-cgi. You can try reconfiguring php5-cgi to use unix sockets as opposed to tcp .. then adjust the server config to point to the socket instead of the tcp ...

ps auxww | grep php5-cgi #-- is the process running?  
netstat -an | grep 9000 # is the port open? 

I executed my localhost and the page displayed the 502 bad gateway message. This helped me:

1. Edit /etc/php5/fpm/pool.d/www.conf
2. Change listen = /var/run/php5-fpm.sock to listen = 127.0.0.1:9000
3. Ensure the location is set properly in nginx.conf.
4. Run sudo service php5-fpm restart

Maybe it will help you.

Source from: http://wildlyinaccurate.com/solving-502-bad-gateway-with-nginx-php-fpm