출처 : http://lintut.com/how-to-install-webmin-on-centos-7/

To get started, login your remote server and follow the steps below:
First, create a new file webmin.repo in /etc/yum.repos.d/ :

vi /etc/yum.repos.d/webmin.repo

and paste below line:

[Webmin]
name=Webmin Distribution Neutral
#baseurl=http://download.webmin.com/download/yum
mirrorlist=http://download.webmin.com/download/yum/mirrorlist
enabled=1

Install webmin GPG key using below command.

rpm --import http://www.webmin.com/jcameron-key.asc

Now, update the repositorys:

yum check-update

Install webmin:

yum install webmin -y

Start the service and make it start automatically

chkconfig webmin on

service webmin start

By default, Webmin will listen on port 10000. Enable webmin Port:

firewall-cmd --add-port=10000/tcp