Nginx pid error fix

If you use systemctl status nginx to check nginx status you may find a pid error appear on status panel. The words that appear may be :

Can't open PID file /run/nginx.pid (yet?) after start: Operation not permitted
Or
Can't open PID file /var/run/nginx.pid (yet?) after start: No such file or directory

This is becasue the pid file not generate before the nginx booted. The solution is to add following sentence into /usr/lib/systemd/system/nginx.service, it will let nginx wait 0.1s before executing the executable.

ExecStartPost=/bin/sleep 0.1

Add this sentence to the [service] part.

Rload and restart the nginx

systemctl daemon-reload
systemctl restart nginx

Problem fixed.