Nginx php html permission denied

After searching , I found it.It's all deals with SELINUX which is a security feature. when using ls -Z

drwxrwxrwx. ec2-user root system_u:object_r:httpd_sys_content_t:s0 www

change this to

drwxrwxrwx. ec2-user root system_u:object_r:httpd_sys_rw_content_t:s0 www

using cmd

chcon -R -t httpd_sys_rw_content_t /var/www

source: https://stackoverflow.com/questions/37710979/nginx-failed-to-open-stream-permission-denied-in-var-www-example-com