I cannot seem to get EasyApache 4 to run pdo_mysql. After provisioning with the correct modules, my error_log fills up with "PHP Warning: PHP Startup: Unable to load dynamic library 'pdo_mysql.so'". It then lists all of the places it looked for pdo_mysql.so, but to no avail.
I have also tried reinstalling php using command line, but it does not install pdo_mysql, either.
php.ini is set correctly, so that is not a concern; PHP is trying to open the module, but it's simply not there, no matter how many times I install using EasyApache or command line and reboot.
I ended up fixing it by manually removing my entire PHP structure, then reinstalling from EasyApache. Fixed it without issue. As far as I can tell, there must have been some remnants of a previous install mucking about because even uninstalling using EasyApache wasn't getting everything.
Luckily, it was my own server and I could nuke everything. If anybody stumbles across this issue on shared hosting, I don't know that there will be an easy solution for you.