PHP-FPM on nginx will not connect to an external MySQL -

I have a sensor server that is running NGNX + PHP-FPM, which is an external database for the purpose of a WordPress installation. Will not be connected to.

I can SSH in websrew and fix mysql to connect to the external mysql database, but when it tries php to connect to the database it fails is.

Where do I look for this problem to solve?

This problem is possible to be related to selinux (as it was

  setsebool at httpd_can_network_connect_db  

or it does not work:

  setenforce 0