LibreNMS PHP7.0 to 7.2

LibreNMS recently moved the minimum PHP version to 7.1.3, with 7.2 recommended. There were some examples of how to do that with Ubuntu 16.04, but after doing so a few things also had to be done. First, there were a bunch of php modules that needed to updated to the 7.2 versions. Second, a little less obvious to me, you have to specifically enable the php7.2 module in apache and disable the 7.0 (in my case) module. I did this by:

sudo a2dismod php7.0

sudo a2enmod php7.2 

Make sure to re-run validate.php afterwards....