Mastering Linux Security and Hardening

Method 1 – adding users to a predefined admin group

The first method, which is the simplest, is to add users to a predefined administrators group and then, if it hasn't already been done, to configure the sudo policy to allow that group to do its job. It's simple enough to do except that different Linux distro families use different admin groups. 

On Unix, BSD, and most Linux systems, you would add users to the wheel group. (Members of the Red Hat family, including CentOS, fall into this category.) When I do the groups command on my CentOS machine, I get this:

[donnie@localhost ~]$ groupsdonnie wheel[donnie@localhost ~]$

This shows that I'm a member of the wheel group. By doing sudo visudo, I'll open the sudo policy file. Scrolling down, ...