From linuxers.org
How to allow users in a group to run all commands in Fedora / CentOS using sudo
This tutorial will guide you on how to allow a group of users to run all the commands without sharing your system root password in Fedora / Redhat / CentOS based Distros.
This is similar to the sudo in Ubuntu. Here we will start by creating a group called “sysadmin”, then we will append a user “chia” to that group which will be able to run any command on the system. Lets start by creating a group and adding a user to it.
[root]# groupadd sysadmin
[root]# usermod -aG sysadmin chia
Now edit the /etc/sudoers. Its possible to edit the file in an editor, but its safer to use visudo instead.
[root]# visudo
Add the following line to the file
%sysadmin ALL=(ALL) ALL
Now you can login as user “chia” and run any command by appending sudo.
[chia]$ sudo ifconfig
You can also gain access to root shell by using password of user “chia”
[chia]$ sudo -s
[sudo] password for chia:
[root]#
