nginx 502 bad gateway

I get a 502 Bad Gateway with nginx when using spawn fcgi to spawn php5-cgi.

I use this to span an instance on server start using the following line in rc.local

/usr/bin/spawn-fcgi -a 127.0.0.1 -p 9000 -u www-data -g www-data -f /usr/bin/php5-cgi -P /var/run/fastcgi-php.pid

presumably I'm getting the error because the spawn-fcgi / php5-cgi dies and there is nothing listening there anymore to parse php.

I get nothing in the logs that I can see anywhere, I'm out of ideas (and new to this setup with nginx)

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

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? 

Go to /etc/php5/fpm/pool.d/www.conf and if you are using sockets or this line is uncommented

listen = /var/run/php5-fpm.sock

Set couple of other values too:-

listen.owner = www-data
listen.group = www-data
listen.mode = 0660

Don't forget to restart php-fpm and nginx. Make sure you are using the same nginx owner and group name.