Installing LibreNMS Monitoring Solution on Rocky Linux

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LibreNMS is a powerful monitoring tool that supports auto-discovery using multiple protocols such as SNMP, ARP, OSPF, and BGP. SNMP, available on most operating systems, including Linux, Windows, and BSDs, is commonly used for monitoring. There are three versions of the SNMP protocol: v1 and v2, secured with a community password, and v3, which supports authentication and encryption. For production environments, SNMP v3 is recommended due to its enhanced security.

In this comprehensive guide, you will learn how to install the LibreNMS monitoring tool on a Rocky Linux server. The guide includes setting up the LEMP Stack (Nginx, MariaDB, and PHP-FPM) and configuring the SNMP service to get your monitoring solution production-ready. By the end of this guide, you’ll be equipped to add new hosts, servers, or devices to LibreNMS for monitoring purposes.

Prerequisites

Before proceeding, ensure that you have the following:

  • A Rocky Linux server (version 8 is used in this guide).
  • A non-root user with sudo/administrator privileges.
  • A local domain name for deployment purposes.

Setting Up Repositories

Let’s begin by setting up the necessary repositories on your Rocky Linux system, specifically the EPEL and PHP Remi repositories.

Execute the following command to add the EPEL repository:

sudo dnf install epel-release

A confirmation prompt will appear; type Y and press ENTER to continue.

install epel

Next, add the PHP Remi repository to gain access to multiple PHP versions, including the latest PHP 8.1, necessary for LibreNMS:

sudo dnf install dnf-utils http://rpms.remirepo.net/enterprise/remi-release-8.rpm

Type Y and press ENTER to proceed.

add remi repo

Verify the added repositories with the command below:

sudo dnf repolist

You should see listings for both the EPEL and Remi repositories.

check repos

Installing Package Dependencies

With the EPEL and Remi repositories in place, proceed to install LibreNMS’s package dependencies, which include the LEMP Stack, SNMP packages, and Python. First, enable the PHP repository module ‘remi-8.1‘ as LibreNMS requires PHP 8 or higher:

sudo dnf reset php
sudo dnf module enable php:remi-8.1

Confirm by typing Y when prompted.

reset php modules

Install the necessary dependencies with the command below:

sudo dnf install bash-completion cronie fping git ImageMagick mariadb-server mtr net-snmp net-snmp-utils nginx nmap php-fpm php-cli php-common php-curl php-gd php-gmp php-json php-mbstring php-process php-snmp php-xml php-zip php-mysqlnd python3 python3-PyMySQL python3-devel python3-redis python3-memcached python3-pip python3-systemd rrdtool unzip

Confirm installation by typing Y and pressing ENTER.

install dependencies

Enable and start essential services, ensuring they run on system boot:

sudo systemctl enable nginx php-fpm mariadb snmpd
sudo systemctl start nginx php-fpm mariadb snmpd

start enable services

Setting up Firewalld

Ensure HTTP and HTTPS services are allowed through the firewalld firewall:

sudo firewall-cmd --permanent --zone public --add-service http
sudo firewall-cmd --permanent --zone public --add-service https

Reload firewalld to apply these changes:

sudo firewall-cmd --reload

List the active firewalld rules to ensure HTTP and HTTPS services are included:

sudo firewall-cmd --list-all

setup firewalld

Downloading LibreNMS Source Code

Download the LibreNMS source code from GitHub and create a dedicated user ‘librenms’ to run the application.

Add the ‘librenms’ user:

sudo useradd librenms -d /opt/librenms -M -r -s "$(which bash)"

Clone the LibreNMS repository:

cd /opt
git clone https://github.com/librenms/librenms.git

download librenms

Set the correct ownership and permissions for the LibreNMS directory:

sudo chown -R librenms:librenms /opt/librenms
sudo chmod 771 /opt/librenms

Configure access control lists for specific directories:

sudo setfacl -d -m g::rwx /opt/librenms/rrd /opt/librenms/logs /opt/librenms/bootstrap/cache/ /opt/librenms/storage/
sudo setfacl -R -m g::rwx /opt/librenms/rrd /opt/librenms/logs /opt/librenms/bootstrap/cache/ /opt/librenms/storage/

setup ownership acls

Installing PHP Dependencies for LibreNMS

Log in as the ‘librenms’ user to install PHP dependencies:

su - librenms

Execute the following script to install PHP dependencies:

./scripts/composer_wrapper.php install --no-dev

install dependencies

Exit the ‘librenms’ user session:

exit

Configuring PHP-FPM

Configure PHP-FPM by editing the /etc/php.ini file and ensuring the timezone is correctly set:

sudo timedatectl set-timezone Europe/Stockholm
sudo nano /etc/php.ini

Find and configure the following line:

date.timezone = Europe/Stockholm

Copy the default PHP-FPM pool to create a specific pool for LibreNMS:

cp /etc/php-fpm.d/www.conf /etc/php-fpm.d/librenms.conf

Edit /etc/php-fpm.d/librenms.conf and adjust the following:

[librenms]
user = librenms
group = librenms
listen = /run/php-fpm-librenms.sock

Restart PHP-FPM to apply the changes:

sudo systemctl restart php-fpm

setup php-fpm

Configuring MariaDB Server

Configure the MariaDB server and create a new database for LibreNMS. Enable the InnoDB engine before proceeding:

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

Include these configurations under the ‘[mysqld]’ section:

[mysqld]
innodb_file_per_table=1
lower_case_table_names=0

Restart the MariaDB service:

sudo systemctl restart mariadb

Create the LibreNMS database and user:

sudo mysql -u root -p
CREATE DATABASE librenms CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
CREATE USER 'librenms'@'localhost' IDENTIFIED BY 'password';
GRANT ALL PRIVILEGES ON librenms.* TO 'librenms'@'localhost';
FLUSH PRIVILEGES;

create database and user

Verify user privileges with:

SHOW GRANTS FOR librenms@localhost;

check privileges

Exit the MariaDB shell:

exit

Setting Up Nginx Server Blocks

Create a specific Nginx server block for your LibreNMS installation using your chosen domain (e.g., librenms.howtoforge.local):

sudo nano /etc/nginx/conf.d/librenms.conf

Include the following configuration:

server {
    listen       80;
    server_name librenms.howtoforge.local;
    root         /opt/librenms/html;
    index        index.php;

    charset utf-8;
    gzip on;
    gzip_types text/css application/javascript text/javascript application/x-javascript image/svg+xml text/plain text/xsd text/xsl text/xml image/x-icon;

    location / {
        try_files $uri $uri/ /index.php?$query_string;
    }

    location ~ [^/]\.php(/|$) {
        fastcgi_pass unix:/run/php-fpm-librenms.sock;
        fastcgi_split_path_info ^(.+\.php)(/.+)$;
        include fastcgi.conf;
    }

    location ~ /\.(?!well-known).* {
        deny all;
    }
}

Check the configuration for syntax errors:

sudo nginx -t

If successful, restart Nginx:

sudo systemctl restart nginx

setup nginx

Configuring SELinux

To accommodate SELinux, ensure it’s set to enforcing mode and make the necessary adjustments for LibreNMS:

Install SELinux management tools:

sudo dnf install policycoreutils-python-utils

install SELinux management tool

Apply file context labels for LibreNMS:

semanage fcontext -a -t httpd_sys_content_t '/opt/librenms/html(/.*)?'
semanage fcontext -a -t httpd_sys_rw_content_t '/opt/librenms/(rrd|storage)(/.*)?'
semanage fcontext -a -t httpd_log_t "/opt/librenms/logs(/.*)?"
semanage fcontext -a -t bin_t '/opt/librenms/librenms-service.py'
restorecon -RFvv /opt/librenms
chcon -t httpd_sys_rw_content_t /opt/librenms/.env

setup selinux labelling

Allow necessary SELinux permissions:

setsebool -P httpd_can_sendmail=1
setsebool -P httpd_execmem 1

Prepare a custom SELinux module to allow necessary permissions:

nano http_fping.tt

Add the following content:

module http_fping 1.0;

require {
    type httpd_t;
    class capability net_raw;
    class rawip_socket { getopt create setopt write read };
}

#============= httpd_t ==============
allow httpd_t self:capability net_raw;
allow httpd_t self:rawip_socket { getopt create setopt write read };

Compile and apply the SELinux module:

checkmodule -M -m -o http_fping.mod http_fping.tt
semodule_package -o http_fping.pp -m http_fping.mod
semodule -i http_fping.pp

setup selinux

Finishing Up the LibreNMS Configurations

Complete the setup by installing command-line utilities, configuring cron jobs, and copy logrotate settings.

Create symbolic links for ‘lnms’ command and copy bash completion scripts:

ln -s /opt/librenms/lnms /usr/bin/lnms
cp /opt/librenms/misc/lnms-completion.bash /etc/bash_completion.d/

Copy default cron and logrotate configurations:

sudo cp /opt/librenms/librenms.nonroot.cron /etc/cron.d/librenms
sudo cp /opt/librenms/misc/librenms.logrotate /etc/logrotate.d/librenms

Edit the SNMP configuration file:

sudo cp /opt/librenms/snmpd.conf.example /etc/snmp/snmpd.conf
sudo nano /etc/snmp/snmpd.conf

Change the default community password:

# Change RANDOMSTRINGGOESHERE to your preferred SNMP community string
com2sec readonly  default        RANDOMSTRINGGOESHERE

Save and close the file.

Download the OS detection script and set appropriate permissions:

curl -o /usr/bin/distro https://raw.githubusercontent.com/librenms/librenms-agent/master/snmp/distro
chmod +x /usr/bin/distro

download distrocheck

Restart the SNMP service to apply changes:

systemctl restart snmpd

Accessing LibreNMS Web Installation

Edit your /etc/hosts file to associate the domain with your server’s IP and access the Installer via a web browser:

192.168.5.100   librenms.howtoforge.local

Visit http://librenms.howtoforge.local/. Ensure all installation requirements are green-checked, indicating readiness for LibreNMS installation.

Click the database icon to proceed.

pre install setup database

Enter database details and click “Check Credentials“.

check database

Choose “Build Database” to initiate database migration.

build database

After completing the database setup, configure the administrator user details and save them.

build database

setup user

The installation is now complete, and you should see the success screen:

installation completes

Finally, validate the installation to ensure all configurations are correct. Address any errors or warnings as suggested by LibreNMS.

login librenms

validate installation librenms

Conclusion

Congratulations! You have successfully installed the LibreNMS Monitoring Solution on Rocky Linux. Familiarize yourself with its core features, including adding monitored hosts, configuring alerts, and integrating with third-party tools like Graylog.

FAQ

What is LibreNMS?
LibreNMS is an open-source network monitoring tool that supports various protocols for comprehensive network management.
Why should I use SNMP v3 over v1 or v2?
SNMP v3 provides enhanced security features, including authentication and encryption, making it more suitable for production environments.
Is PHP 8.1 mandatory for LibreNMS installation?
Yes, LibreNMS requires at least PHP 8 for installation and operation, hence the necessity for enabling the PHP Remi 8.1 repository.
How to troubleshoot if a service doesn’t start automatically?
Verify the service status using `systemctl status service_name` and check the error logs for detailed information.
Where can I find more information on adding devices to monitor?
Refer to the LibreNMS documentation and community forums for detailed guides on adding and managing monitored devices.