Check this out:
https://www.cloudflare.com/technical-resources/#mod_cloudflare

Option 1: Installation from Packages

Download the appropriate package to your web server and install it using your operating system’s ‘rpm’ or ‘dkpg’ commands.

For RedHat / CentOS / CloudLinux:

For Debian / Ubuntu:

RHEL/CentOS/CloudLinux

RHEL/CentOS/CloudLinux 7 (64-bit) RHEL/CentOS/CloudLinux 6 (64-bit)

Debian

Debian 8 (64-bit) Debian 7 (64-bit)

Ubuntu

Ubuntu 16.04 (64-bit) Ubuntu 15.10 (64-bit) Ubuntu 15.04 (64-bit)Ubuntu 14.04 (64-bit) Ubuntu 12.04 (64-bit)