CentOS -- Missing PHP extensions. Please install and enable them on your LibreNMS server

Hi,

Facing this problem for Libre NMS WEB Interface. I am using CentOS 7. There is no error for the for the mbstring for not being installed. I can find the help for the Ubuntu but not for CentOS 7.

Missing PHP extensions. Please install and enable them on your LibreNMS server.
mbstring

./validate.php

====================================

Component Version
LibreNMS 1.39-37-g5fd81db
DB Schema 249
PHP 7.0.29
MySQL 5.5.56-MariaDB
RRDTool 1.4.8
SNMP NET-SNMP 5.7.2

====================================

[OK] Composer Version: 1.6.5
[OK] Dependencies up-to-date.
[OK] Database connection successful
[OK] Database schema correct
[WARN] Missing optional PHP extension: posix
[FIX] It is suggested you install php-process or the one that matches your php version
[FIX] Check the cron job to make sure it is running and using discovery-wrapper.py

The fix is in the output you’ve provided, install php-process and install php-mbstring and enable it.

I am kindl of newbie. If you can please tell, how to enable enable?

Assuming nothing is wrong with your repos in CentOS:
sudo yum install php-process php-mbstring
PHP modules install by Yum are enabled by default (or at least I haven’t encountered ones that aren’t).