Set Up Zabbix on CentOS, RHEL 8

This guide will walk you through the steps to install and configure Zabbix 4.4 server on a CentOS, RHEL 8.

Note: With CentOS 8 release, yum command has been replaced with dnf and in near future yum package manager will be discontinued. It is now recommended to use dnf for installing packages but if you still wish to use yum you can use it.

 

Prerequisites

You will need one CentOS/RHEL 8 (physical or virtual) machine with minimal installed having root user privileges.

Turnoff SELinux

You should change from SELINUX=enforcing to SELINUX=disable in /etc/selinux/config file for smooth installation of the packages:

vi /etc/selinux/config

SELINUX=disabled

Save and close.

Now reboot your CentOS/RHEL machine to take changes into effect:

reboot

Add Epel Repository

It is always recommended to add extra packages for enterprise Linux repository before installing packages on your CentOS or RHEL:

yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm
ARCH=$( /bin/arch )
dnf config-manager --set-enabled PowerTools

If you are on RHEL 8, execute the following command as well:

subscription-manager repos --enable "codeready-builder-for-rhel-8-${ARCH}-rpms"

Add Zabbix Repository

Zabbix isn't available in yum package manager by default, so you will need to install Zabbix official repository on your CentOS or RHEL 8:

dnf -y install http://repo.zabbix.com/zabbix/4.4/rhel/8/x86_64/zabbix-release-4.4-1.el8.noarch.rpm

Install Apache

You can install the latest version of apache by typing the following command:

dnf -y install httpd httpd-devel

Install MySQL

You will need to install MySQL database using the following command:

dnf -y install mysql-server mysql

Start Apache, MySQL Service

Now start Apache and MySQL service and make them persistent even when system reboots:

systemctl start httpd
systemctl start mysqld

systemctl enable httpd
systemctl enable mysqld

Secure MySQL

By default MySQL database is not secure and anyone can intrude into your database, so make it secure by executing the following script and follow the instruction:

mysql_secure_installation

Securing the MySQL server deployment.
Connecting to MySQL using a blank password.

VALIDATE PASSWORD COMPONENT can be used to test passwords
and improve security. It checks the strength of password
and allows the users to set only those passwords which are
secure enough. Would you like to setup VALIDATE PASSWORD component?

Press y|Y for Yes, any other key for No: y

There are three levels of password validation policy:

LOW    Length >= 8
MEDIUM Length >= 8, numeric, mixed case, and special characters
STRONG Length >= 8, numeric, mixed case, special characters and dictionary                  file

Please enter 0 = LOW, 1 = MEDIUM and 2 = STRONG: 1
Please set the password for root here.

New password:
Re-enter new password:

Estimated strength of the password: 100
Do you wish to continue with the password provided?(Press y|Y for Yes, any other key for No) : y
By default, a MySQL installation has an anonymous user,
allowing anyone to log into MySQL without having to have
a user account created for them. This is intended only for
testing, and to make the installation go a bit smoother.
You should remove them before moving into a production
environment.

Remove anonymous users? (Press y|Y for Yes, any other key for No) : y
Success.

Normally, root should only be allowed to connect from
'localhost'. This ensures that someone cannot guess at
the root password from the network.

Disallow root login remotely? (Press y|Y for Yes, any other key for No) : y
Success.

By default, MySQL comes with a database named 'test' that
anyone can access. This is also intended only for testing,
and should be removed before moving into a production
environment.

Remove test database and access to it? (Press y|Y for Yes, any other key for No) : y
 - Dropping test database...
Success.

 - Removing privileges on test database...
Success.

Reloading the privilege tables will ensure that all changes
made so far will take effect immediately.

Reload privilege tables now? (Press y|Y for Yes, any other key for No) : y
Success.

All done!

Install Zabbix

Now you can install the Zabbix server and web frontend with MySQL database using the following command:

dnf -y install zabbix-server-mysql zabbix-web-mysql zabbix-apache-conf

You will also need to install Zabbix agent to collect data about the Zabbix server itself:

dnf -y install zabbix-agent 

Configure MySQL

At this stage you will need to create a user and a database for Zabbix like below.

mysql -u root -p

create database zabbix character set utf8; 
create user 'zabbix'@'localhost' identified by 'TypeYourPasswordHere';
grant all privileges on zabbix.* to 'zabbix'@'localhost';
flush privileges;
quit;

Import Zabbix Schema

Find out the Zabbix database schema file and then import it into your newly created database:

find / -name create.sql.gz

Output
/usr/share/doc/zabbix-server-mysql/create.sql.gz

Now import this schema file into database like below:

zcat /usr/share/doc/zabbix-server-mysql/create.sql.gz | mysql -u zabbix -p zabbix

Setting Zabbix Database Password:

Now edit the /etc/zabbix/zabbix_server.conf file, uncomment by removing # and update the following parameter with your zabbix database user password:

vi /etc/zabbix/zabbix_server.conf

### Option: DBPassword
#       Database password.
#       Comment this line if no password is used.
#
# Mandatory: no
# Default:
DBPassword=TypeYourPasswordHere

Save and close.

Configure PHP

The Zabbix installation process created an PHP configuration file that contains PHP settings. It is located in the directory /etc/php-fpm.d/. You just need to uncomment date.timezone parameter and update it with your timezone. You can check supported time zones on http://php.net/manual/en/timezones.php to find the right one for you.

vi /etc/php-fpm.d/zabbix.conf

[zabbix]
user = apache
group = apache

listen = /run/php-fpm/zabbix.sock
listen.acl_users = apache,nginx
listen.allowed_clients = 127.0.0.1

pm = dynamic
pm.max_children = 50
pm.start_servers = 5
pm.min_spare_servers = 5
pm.max_spare_servers = 35

php_value[session.save_handler] = files
php_value[session.save_path]    = /var/lib/php/session

php_value[max_execution_time] = 300
php_value[memory_limit] = 128M
php_value[post_max_size] = 16M
php_value[upload_max_filesize] = 2M
php_value[max_input_time] = 300
php_value[max_input_vars] = 10000
php_value[date.timezone] = Asia/Karachi

Save and close.

Now restart Apache and PHP service to take changes into effect.

systemctl restart httpd
systemctl restart php-fpm
systemctl enable php-fpm

Start Zabbix Service

Its time to start Zabbix server and make it persistent even when system reboots:

systemctl start zabbix-server
systemctl enable zabbix-server

systemctl start zabbix-agent
systemctl enable zabbix-agent

Check the Zabbix server status before proceeding to next step.

systemctl status zabbix-server

● zabbix-server.service - Zabbix Server
   Loaded: loaded (/usr/lib/systemd/system/zabbix-server.service; disabled; vendor preset: disabled)
   Active: active (running) since Wed 2019-12-18 10:38:36 PKT; 4s ago
  Process: 15167 ExecStart=/usr/sbin/zabbix_server -c $CONFFILE (code=exited, status=0/SUCCESS)
 Main PID: 15169 (zabbix_server)
    Tasks: 38 (limit: 11513)
   Memory: 38.1M
   CGroup: /system.slice/zabbix-server.service

The Zabbix server status shows up and running, so lets proceed to next step.

 Update Firewall Rules

firewall-cmd --permanent --zone=public --add-service=http
firewall-cmd --reload

Configure Zabbix

The Zabbix web interface lets us see reports and add network devices that you wish to monitor, but it needs some initial setup before we can use it. Open up your web browser and navigate to http://Your_Server_IP/zabbix

The first screen like below will greet you a welcome message.

Click Next step to continue.

This page will show you the table that lists all of the prerequisites to run Zabbix. If anything missing make sure to fix it first then proceed to Next.

Provide zabbix database user password and proceed to next.

Keep it default and proceed next.

This is the summary screen, verify and proceed next.

This screen confirms that you have successfully installed Zabbix.

Click Finish

Zabbix frontend is ready! The default user name is Admin, password zabbix.

Once logged in, you will see below dashboard screen and from here you can administer and manage your Zabbix server.

Install Zabbix Agent

In this step we will show you how to install and configure Zabbix agent 4.4 on a CentOS, RHEL, Ubuntu and Windows machine.

For CentOS/RHEL 7

dnf -y install http://repo.zabbix.com/zabbix/4.4/rhel/7/x86_64/zabbix-release-4.4-1.el7.noarch.rpm
dnf -y install zabbix-agent

Now edit /etc/zabbix/zabbix_agentd.conf file and update the Server= parameter with your zabbix server IP

vi /etc/zabbix/zabbix_agentd.conf

### Option: Server
#       List of comma delimited IP addresses, optionally in CIDR notation, or DNS names of Zabbix servers and Zabbix proxies.
#       Incoming connections will be accepted only from the hosts listed here.
#       If IPv6 support is enabled then '127.0.0.1', '::127.0.0.1', '::ffff:127.0.0.1' are treated equally
#       and '::/0' will allow any IPv4 or IPv6 address.
#       '0.0.0.0/0' can be used to allow any IPv4 address.
#       Example: Server=127.0.0.1,192.168.1.0/24,::1,2001:db8::/32,zabbix.example.com
#
# Mandatory: yes, if StartAgents is not explicitly set to 0
# Default:
# Server=

Server=Your_Zabbix_Server_IP

Save and close.

systemctl restart zabbix-agent

For CentOS/RHEL 8

dnf -y install http://repo.zabbix.com/zabbix/4.4/rhel/8/x86_64/zabbix-release-4.4-1.el8.noarch.rpm
dnf -y install zabbix-agent

Now edit /etc/zabbix/zabbix_agentd.conf file and update the Server= parameter with your zabbix server IP

vi /etc/zabbix/zabbix_agentd.conf

### Option: Server
#       List of comma delimited IP addresses, optionally in CIDR notation, or DNS names of Zabbix servers and Zabbix proxies.
#       Incoming connections will be accepted only from the hosts listed here.
#       If IPv6 support is enabled then '127.0.0.1', '::127.0.0.1', '::ffff:127.0.0.1' are treated equally
#       and '::/0' will allow any IPv4 or IPv6 address.
#       '0.0.0.0/0' can be used to allow any IPv4 address.
#       Example: Server=127.0.0.1,192.168.1.0/24,::1,2001:db8::/32,zabbix.example.com
#
# Mandatory: yes, if StartAgents is not explicitly set to 0
# Default:
# Server=

Server=Your_Zabbix_Server_IP

Save and close.

systemctl restart zabbix-agent

For Ubuntu 16

sudo dpkg -i http://repo.zabbix.com/zabbix/4.4/ubuntu/pool/main/z/zabbix-release/zabbix-release_4.4-1%2Bxenial_all.deb
sudo apt-get install zabbix-agent

Now edit /etc/zabbix/zabbix_agentd.conf file and update the Server= parameter with your zabbix server IP

sudo nano /etc/zabbix/zabbix_agentd.conf

### Option: Server
#       List of comma delimited IP addresses, optionally in CIDR notation, or DNS names of Zabbix servers and Zabbix proxies.
#       Incoming connections will be accepted only from the hosts listed here.
#       If IPv6 support is enabled then '127.0.0.1', '::127.0.0.1', '::ffff:127.0.0.1' are treated equally
#       and '::/0' will allow any IPv4 or IPv6 address.
#       '0.0.0.0/0' can be used to allow any IPv4 address.
#       Example: Server=127.0.0.1,192.168.1.0/24,::1,2001:db8::/32,zabbix.example.com
#
# Mandatory: yes, if StartAgents is not explicitly set to 0
# Default:
# Server=

Server=Your_Zabbix_Server_IP

Save and close.

sudo service zabbix-agent restart

For Ubuntu 18/19

sudo dpkg -i http://repo.zabbix.com/zabbix/4.4/ubuntu/pool/main/z/zabbix-release/zabbix-release_4.4-1%2Bbionic_all.deb
sudo apt-get install zabbix-agent

Now edit /etc/zabbix/zabbix_agentd.conf file and update the Server= parameter with your zabbix server IP

sudo nano /etc/zabbix/zabbix_agentd.conf

### Option: Server
#       List of comma delimited IP addresses, optionally in CIDR notation, or DNS names of Zabbix servers and Zabbix proxies.
#       Incoming connections will be accepted only from the hosts listed here.
#       If IPv6 support is enabled then '127.0.0.1', '::127.0.0.1', '::ffff:127.0.0.1' are treated equally
#       and '::/0' will allow any IPv4 or IPv6 address.
#       '0.0.0.0/0' can be used to allow any IPv4 address.
#       Example: Server=127.0.0.1,192.168.1.0/24,::1,2001:db8::/32,zabbix.example.com
#
# Mandatory: yes, if StartAgents is not explicitly set to 0
# Default:
# Server=

Server=Your_Zabbix_Server_IP

Save and close.

sudo systemctl restart zabbix-agent

For Windows

Zabbix Windows agent can be installed from Windows MSI installer packages (32-bit or 64-bit) available for download:

To install, double-click the downloaded MSI file.

Click Next

Accept the licence to proceed to the next step.

Specify the following parameters and click next.

Click next

Click install

Click finish

Zabbix components along with the configuration file is now installed in a Zabbix Agent folder in Program Files. zabbix_agentd.exe will be set up as Windows service with automatic startup.

Adding Devices to Zabbix Server

When you are done installing Zabbix agent on your Linux or Windows machines, go back to your Zabbix server web interface and start creating devices to monitor them.

Navigate to Configuration tab

Click Hosts then click Create host

This is our Windows 10 zabbix agent machine. Specify the following parameters according to yours and click Add

Click Templates and add the templates according to your need.

When done adding hosts, navigate back to Dashboard and there you can see number of hosts you have added in zabbix server to monitor.

Navigate to Graphs, select your host and graph from the drop down list and see if your host monitoring data is being collected like below.

This is how you can add and monitor your Windows and Linux machines in zabbix server. For the devices like switches, routers, firewall etc, of course you can not install zabbix agent, but you can add and monitor them in zabbix server via SNMP and IPMI interface.

Wrapping up

In this tutorial, you set up a simple and secure solution which will help you monitor your servers. It can now warn you of problems, and you have the opportunity to plot some graphs based on the obtained data so you can analyze it and plan accordingly.