Managing your /etc configuration files using version control is a good practice. Trust me, someday this will save your skin.
In the post I'll share setup notes for using etckeeper with git version control. You can install etckeeper and git using system package manager.
# Initialize etckeeper
sudo etckeeper init
# Commit all your /etc/ configurations into git
sudo etckeeper commit '...enable etckeeper...'
# Check the commit history of file
$ sudo git log /etc/passwd
commit 322b63ede6cf3073a8f48a883b49d5b3b60fdfb9
Author: arky <arky@localhost.localdomain>
Date: Wed Mar 5 07:11:47 2014 +0000
...enable etckeeper...
There is very little etckeeper documentation out there. You can learn more from this dated Ubuntu Server 10.04 etckeeper wiki page.