nginx error connect to php5-fpm.sock failed (13: Permission denied)

Question

I update nginx to 1.4.7 and php to 5.5.12, After that I got the 502 error. Before I update everything works fine.

Answer 1

Check which user runs nginx. As of Ubuntu 12.04 nginx runs by nginx user which is not a member of www-data group.

usermod -a -G www-data nginx

and restarting nginx and php5-fpm daemons solves the problem.