How to Install and Setup Munin on CentOS 7

Munin is an excellent system monitoring tool similar to RRD tool which will give you ample information about system performance on multiple fronts like a disk, network, process, system, and users. These are some of the default properties Munin monitors.

Munin can help system administrators to analyze the trend of the computer system whether it is experiencing problems or not. It can be an easier alternative to the popular open-source software zabbix monitoring.

In this article I will show how to install and setup munin on CentOS 7 server.

How munin works?

Munin works on a client-server model. Munin server process on the main server try to collect data from client daemon which is running locally(Munin can monitor it’ss own resources) or from a remote client(Munin can monitor hundreds of machines) and displays them in graphs on it’s web interface.

Install and Setup Munin on CentOS 7

Follow the below steps to install and setup munin on your CentOS 7 server.

1. First of all install and enable EPEL Repository on CentOS 7.

2. To run the munin you will need web server, that’s why install the Apache web server with munin.

# yum install httpd munin munin-node -y

3. Start and enable apache and munin at boot.

# systemctl start httpd
# systemctl enable httpd
# systemctl start munin-node
# systemctl enable munin-node

4. If you want munin to use the name centos72.looklinux.local instead of localhost. Please open edit the setting in /etc/munin/munin.conf

# vim /etc/munin/munin.conf

[localhost]
    address 127.0.0.1
    use_node_name yes

Change to :

[centos72.looklinux.local]
    address 127.0.0.1
    use_node_name yes

5. You can also change the hostname of the munin node.

# vim /etc/munin/munin-node.conf

host_name localhost.localdomain

Change to :

host_name centos72.looklinux.local

6. Now edit the Apache Virtual host configuration file to add the permission to access your network.

# vim /etc/httpd/conf.d/munin.conf

Add network segment that you allow to access to the CentOS server.

AuthUserFile /etc/munin/munin-htpasswd
AuthName "Munin"
AuthType Basic
require valid-user

Order Deny,Allow
Deny from all
Allow from 127.0.0.1 192.168.0.0/24
..
..

7. Munin statistics page shall be protected by a username and password. We can add the new user (admin) and password to /etc/munin/munin-htpasswd with htpasswd command line. So we have to setup basic Apache authentication before we can start access the munin statistic page.

# htpasswd /etc/munin/munin-htpasswd admin
New password:
Re-type new password:
Adding password for user admin

8. Restart Apache and Munin.

# /etc/init.d/apache restart

# /etc/init.d/munin-node restart

9. Allow port 80 in the firewall permanently to access munin.

Check default zone:

# firewall-cmd --get-active-zones
public
  interfaces: ens160

Allow port 80 permanently in firewalld:

# firewall-cmd --permanent --zone=public --add-port=80/tcp
success

Reload Firewall setting:

# firewall-cmd --reload
success

List all active firewalld configuration :

# firewall-cmd --list-all
public (default, active)
  interfaces: ens160
  sources:
  services: dhcpv6-client ssh
  ports: 80/tcp
  masquerade: no
  forward-ports:
  icmp-blocks:
  rich rules:

10. Accessing Munin web interface

http://192.168.0.14/munin/