Groups

Groups really don't become very important unless you are managing a complex system with varying levels of permissions. And on the McKelvey cluster, the EIT department handles all of the groups and group policy. It may still be worth an overview though.

The most common uses of Groups have already been touched on. Say you need to add a user to the docker group. You would run sudo usermod -a -G docker myuser 

All existing groups are listed in /etc/groups 

To list all the groups a user is a member of. If you do not list a user, it will list the groups of the current user. You can also list multiple users and it will list each user and their groups.

[root@localhost ~]# groups
root

[root@localhost ~]# groups bradr
bradr : bradr dialout sudo

[root@localhost ~]# groups root bradr postgres
root : root
bradr : bradr dialout sudo
postgres : postgres ssl-cert