How To Install Cacti on RHEL 8 / CentOS 8

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This guide will cover how to install and configure Cacti on RHEL 8 / CentOS 8. Monitoring is a key component of any Infrastructure. At ComputingPost, so far, we have covered the usage of Zabbixtelegraf/ InfluxdbGrafana, and Prometheus. Cacti is a completely open-source network monitoring and graphing tool that was designed as a front-end application for the industry-standard data logging tool – RRDtool.

Cacti harnesses the power of RRDTool’s data storage and graphing functionality. Some good features of Cacti include:

  • Fast polling of metrics
  • Support for multiple data acquisition methods
  • Support for advanced graph templating
  • User management functionality with ACL

Cacti provides an intuitive and easy to use web interface for managing network monitoring and configurations. There are dependencies needed for building and running Cacti on RHEL 8 / CentOS 8. This section will cover installation and configuration of each component.

Step 1: Install Build tools and System Dependencies

Upgrade your OS:

sudo dnf -y update
sudo reboot

Start with installation of Development Tools set.

After installation of Development tools, install SNMP packages.

sudo dnf install -y net-snmp net-snmp-utils rrdtool

Step 2: Install php and required extensions

Install PHP and extensions required by Cacti on your RHEL / CentOS 8.

sudo dnf -y install @php
sudo dnf -y install php php-mysqlnd,curl,gd,intl,pear,recode,ldap,xmlrpc,snmp,mbstring,gettext,gmp,json,xml,common

Verify PHP version and loaded modules.

$ php -v
PHP 7.2.24 (cli) (built: Oct 22 2019 08:28:36) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies

Set PHP Paramenets inside /etc/php.ini file.

sudo vim /etc/php.ini 

Set correct timezone:

date.timezone = Africa/Nairobi

Change PHP memory limit to 400M

memory_limit = 512M

Update Maximum execution time of each script:

max_execution_time = 300

Start php-fpm service.

sudo systemctl enable --now php-fpm

Confirm status.

$ systemctl status php-fpm
 php-fpm.service - The PHP FastCGI Process Manager
    Loaded: loaded (/usr/lib/systemd/system/php-fpm.service; enabled; vendor preset: disabled)
    Active: active (running) since Sun 2019-03-17 10:23:52 EAT; 5s ago
  Main PID: 31139 (php-fpm)
    Status: "Ready to handle connections"
     Tasks: 6 (limit: 11510)
    Memory: 38.2M
    CGroup: /system.slice/php-fpm.service
            ├─31139 php-fpm: master process (/etc/php-fpm.conf)
            ├─31140 php-fpm: pool www
            ├─31141 php-fpm: pool www
            ├─31142 php-fpm: pool www
            ├─31143 php-fpm: pool www
            └─31144 php-fpm: pool www
 Mar 17 10:23:52 rhel8.local systemd[1]: Starting The PHP FastCGI Process Manager…
 Mar 17 10:23:52 rhel8.local systemd[1]: Started The PHP FastCGI Process Manager.

Step 3: Install Apache Web server

Use the command below to install Apache httpd server.

sudo dnf -y install @httpd

Start and enable service to start at boot.

sudo systemctl enable --now httpd

Status should indicate running.

$ systemctl status httpd
 httpd.service - The Apache HTTP Server
    Loaded: loaded (/usr/lib/systemd/system/httpd.service; enabled; vendor preset: disabled)
   Drop-In: /usr/lib/systemd/system/httpd.service.d
            └─php-fpm.conf
    Active: active (running) since Sun 2019-03-17 10:49:20 EAT; 2s ago
      Docs: man:httpd.service(8)
  Main PID: 32106 (httpd)
    Status: "Started, listening on: port 443, port 80"
     Tasks: 213 (limit: 11510)
    Memory: 29.2M
    CGroup: /system.slice/httpd.service
            ├─32106 /usr/sbin/httpd -DFOREGROUND
            ├─32108 /usr/sbin/httpd -DFOREGROUND
            ├─32109 /usr/sbin/httpd -DFOREGROUND
            ├─32110 /usr/sbin/httpd -DFOREGROUND
            └─32111 /usr/sbin/httpd -DFOREGROUND
 Mar 17 10:49:20 rhel8.local systemd[1]: Starting The Apache HTTP Server…
 Mar 17 10:49:20 rhel8.local httpd[32106]: Server configured, listening on: port 443, port 80
 Mar 17 10:49:20 rhel8.local systemd[1]: Started The Apache HTTP Server.

Allow http and https ports on the firewall.

sudo firewall-cmd --add-service=http,https --permanent
sudo firewall-cmd --reload

Ref: How to Install Apache with mod_ssl & mod_http2 on RHEL 8

Step 4: Install and Configure Database Server

You can choose to use MySQL or MariaDB database server. if you don’t have either installed, below guides should be helpful.

sudo dnf -y install @mariadb

Start and enable mariadb service:

sudo systemctl enable --now mariadb

Secure your database server:

sudo mysql_secure_installation

Reference:

After Database server installation, create database and user for Cacti Monitoring tool.

$ sudo mysql -u root -p
CREATE DATABASE cacti;
GRANT ALL ON cacti.* TO 'cacti'@'localhost' IDENTIFIED BY 'StrongDBPassword';
FLUSH PRIVILEGES;
exit 

Tune MariaDB database for Cacti

Add the following settings under [mysqld] setion the file /etc/my.cnf.d/mariadb-server.cnf

sudo vim /etc/my.cnf.d/mariadb-server.cnf

Add the following settings inside mysqld section:

[mysqld]
character-set-server=utf8mb4
collation-server=utf8mb4_unicode_ci
max_heap_table_size=128M
tmp_table_size=128M
join_buffer_size=256M
innodb_buffer_pool_size=512M
innodb_doublewrite=OFF
innodb_flush_log_at_timeout=3
innodb_read_io_threads=32
innodb_write_io_threads=16
innodb_buffer_pool_instances=5

Restart mariadb service after adding the lines.

sudo systemctl restart mariadb

Step 5: Download and Configure Cacti

Download the latest release of Cacti tarball to your system.

mkdir cacti && cd cacti
curl -SL https://www.cacti.net/downloads/cacti-latest.tar.gz | tar --strip 1 -xzf -

Move cacti folder to /var/www/html directory.

cd ..
sudo mv cacti/ /var/www/html/

Import Cacti database data

sudo mysql -u root -p cacti < /var/www/html/cacti/cacti.sql

Setup mysql timezone for cacti database user.

mysql_tzinfo_to_sql /usr/share/zoneinfo | sudo mysql -u root -p mysql

Grant cacti MySQL database user access to Timezone database:

$ sudo mysql -u root -p
GRANT SELECT ON mysql.time_zone_name TO [email protected];
ALTER DATABASE cacti CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
FLUSH PRIVILEGES;
QUIT

Configure SELinux.

sudo semanage fcontext -a -t httpd_sys_rw_content_t "/var/www/html/cacti(/.*)?"
sudo restorecon -Rv /var/www/html/cacti

You need to restart apache service after making above modifications,

sudo systemctl restart httpd php-fpm

Configure Cacti

Edit the file /var/www/html/cacti/include/config.php and set database connection parameters.

$ sudo vi /var/www/html/cacti/include/config.php
$database_type     = 'mysql';
$database_default  = 'cacti';
$database_hostname = 'localhost';
$database_username = 'cacti';
$database_password = 'StrongDBPassword';
$database_port     = '3306';
.............

Replace StrongDBPassword with your cacti user database password. When done. save file and exit.

install-cacti-rhel-8-centos-8-configure-db

Create Cacti system log file.

sudo touch /var/www/html/cacti/log/cacti.log

Set directory permissions

sudo chown -R apache:apache  /var/www/html/cacti

Setup Cacti cron job.

sudo crontab -u apache -e

Add below.

*/5 * * * * php /var/www/html/cacti/poller.php > /dev/null 2>&1

Step 6: Access Cacti installation wizard

Access Cacti Installation Wizard interface on http://[ServerIP/Hostname]/cacti.

install-cacti-rhel-8-centos-8-login-1024x569

The default Logins are:

  • Username: admin
  • Password: admin

Change password on the next screen.

install-cacti-rhel-8-centos-8-change-password

The new password should:

  • Contain at least 1 numerical character!
  • Contain at least 1 special character!

Accept GPL License Agreement and click “Begin

install-cacti-rhel-8-centos-8-license-agreement-1024x656

All pre-installation checks should show green – passed.

install-cacti-rhel-8-centos-8-checks

Select type of installation in the next window.

install-cacti-rhel-8-centos-8-choose-server-type

Ensure that Directory Permission Checks are Okay.

install-cacti-rhel-8-centos-8-permissions-checks

Confirm that all binaries all located and click Next.

install-cacti-rhel-8-centos-8-07

Select default data source profile for polling sources.

install-cacti-rhel-8-centos-8-08

Select Device templates to be used after installation.

install-cacti-rhel-8-centos-8-09

Confirm database settings are okay.

install-cacti-rhel-8-centos-8-10

Confirm installation.

install-cacti-rhel-8-centos-8-11

Installation should start, wait for it to finish then access cacti administration web dashboard.

install-cacti-rhel-8-centos-8-12

install-cacti-rhel-8-centos-8-13

install-cacti-rhel-8-centos-8-14-1024x441

Step 7: Monitor Linux Servers with Cacti

Start and enable snmpd daemon to start at boot.

sudo systemctl enable --now snmpd

Confirm it is running.

$ systemctl status snmpd
 ● snmpd.service - Simple Network Management Protocol (SNMP) Daemon.
    Loaded: loaded (/usr/lib/systemd/system/snmpd.service; enabled; vendor preset: disabled)
    Active: active (running) since Sun 2019-03-17 12:24:50 EAT; 4s ago
  Main PID: 3129 (snmpd)
     Tasks: 1 (limit: 11510)
    Memory: 4.9M
    CGroup: /system.slice/snmpd.service
            └─3129 /usr/sbin/snmpd -LS0-6d -f
 Mar 17 12:24:49 rhel8.local systemd[1]: Starting Simple Network Management Protocol (SNMP) Daemon….
 Mar 17 12:24:50 rhel8.local snmpd[3129]: NET-SNMP version 5.8
 Mar 17 12:24:50 rhel8.local systemd[1]: Started Simple Network Management Protocol (SNMP) Daemon..

Add the Linux server for monitoring.  Login to Cacti as admin user and go to:

Console > Create > New Device

Provide Server details and save the configuration.

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