Nginx Proxy Server 502 Error

In the CentOS system, Nginx Proxy server always appear 502 errors, Baidu various search, out of the answer is basically the same, do not know where everyone copied, the problem is not resolved, and finally the answer from Google found:

Total return is a problem with the CentOS system, and the following command is performed to resolve the issue:

grep Nginx/var/log/audit/audit.log | Audit2allow-m Nginx

Semodule-i nginx.pp

Or

sudo cat /var/log/audit/audit.log | grep nginx | audit2allow -M mynginxsudo semodule -i mynginx.pp

Nginx Proxy Server 502 Error