linux下出现nginx Failed to read PID from file /run/nginx.pid: Invalid argument

解决方法：

mkdir -p /etc/systemd/system/nginx.service.d 
printf "[Service]\nExecStartPost=/bin/sleep 0.1\n" > /etc/systemd/system/nginx.service.d/override.conf 

然后 
systemctl daemon-reload 
systemctl restart nginx.service