SELinux

To disable SELinux, edit

sed -i 's/^SELINUX=.*/SELINUX=disabled/g' /etc/selinux/config

Now you need to reboot. If you don’t want to reboot, disable it for current session with

setenforce 0

If you use SELinux, you may need to configure it for each applications.

For web server

setsebool httpd_can_network_connect true
setsebool -P httpd_can_network_connect_db 1
setsebool -P memcached_connect_any 1

CURL ERROR 7 could not establish a secure connection to WordPress.org
SELinux allow non default SSH port