Steps to Install LibreNMS on CentOS 8 / RHEL 8

Steps-to-Install-LibreNMS-on-CentOS-8-_RHEL-8

LibreNMS, a fully-featured network monitoring tool that is based on PHP, MySQL, and SNMP. If you are looking for auto-discovering network monitoring tool, then LibreNMS is the right tool. It supports a wide range of network hardware and OS including Juniper, Cisco, Linux, Foundry, FreeBSD, Brocade, HP, Windows, etc… Before we install LibreNMS let’s see its benefits.

Features of LibreNMS:

Let’s see the top features of LibreNMS monitoring tool:

  • Automatic discovery – It will help you to automatically discover your entire network using CDP, FDP, LLDP, OSPF, BGP, SNMP, and ARP
  • API Access – It provides you a full API to manage, graph, and retrieve data from your install.
  • Updates Automatically – Using LibreNMS you get to stay up to date automatically with new features and bug fixes.
  • Customizable alerting – Get a highly flexible alerting system, notify via email, IRC, Slack, DingTalk, and more.
  • Support for Distributed Polling through horizontal scaling which grows with your network
  • Billing system – Based on usage or transfer you can easily generate bandwidth bills for ports on your network
  • Android and iOS application – There is also a native iPhone/Android App available that provides core functionality.
  • Multiple authentication methods: MySQL, HTTP, LDAP, Radius, Active Directory
  • Integration support for: NfSen, collected, SmokePing, RANCID, Oxidized

Install required dependencies

Let’s start the installation with dependencies that are required by the application. You can add the EPEL repository to RHEL / CentOS 8 using the steps given below.

Steps to Install EPEL Repository on RHEL / CentOS 8

To install the required dependencies you need to open your terminal and run the below commands

sudo dnf -y install yum-utils
sudo dnf -y install   git cronie fping jwhois ImageMagick mtr MySQL-python net-snmp net-snmp-utils nmap python-memcached rrdtool policycoreutils-python httpd mariadb mariadb-server unzip python3 python3-pip

Install PHP

CentOS 7 comes with php 5.4 which is not compatible with LibreNMS. There are multiple ways to install php 7.x on CentOS 7, like Webtatic, Remi or SCL, the last two are maintained by Remi Collet of RedHat.

Running with Remi PHP

yum localinstall http://rpms.remirepo.net/enterprise/remi-release-7.rpm
Install the yum-config-manager to change to Remi PHP 7.3 Repo.

yum install yum-utils
yum-config-manager --enable remi-php73
Install the required packages
yum install mod_php php-cli php-common php-curl php-gd php-mbstring php-process php-snmp php-xml php-zip php-memcached php-mysqlnd
Running with CentOS SCL php
yum install centos-release-scl
yum install rh-php72 rh-php72-php-cli rh-php72-php-common rh-php72-php-curl rh-php72-php-gd rh-php72-php-mbstring rh-php72-php-process rh-php72-php-snmp rh-php72-php-xml rh-php72-php-zip rh-php72-php-memcached rh-php72-php-mysqlnd
ln -s /opt/rh/rh-php72/root/usr/bin/php /usr/bin/php
ln -s /opt/rh/httpd24/root/etc/httpd/conf.d/rh-php72-php.conf /etc/httpd/conf.d/
ln -s /opt/rh/httpd24/root/etc/httpd/conf.modules.d/15-rh-php72-php.conf /etc/httpd/conf.modules.d/
ln -s /opt/rh/httpd24/root/etc/httpd/modules/librh-php72-php7.so /etc/httpd/modules/
Add librenms user
useradd librenms -d /opt/librenms -M -r
usermod -a -G librenms apache

Download LibreNMS

cd /opt
git clone https://github.com/librenms/librenms.git
Set permissions
chown -R librenms:librenms /opt/librenms
chmod 770 /opt/librenms
setfacl -d -m g::rwx /opt/librenms/rrd /opt/librenms/logs /opt/librenms/bootstrap/cache/ /opt/librenms/storage/ /opt/librenms/cache
setfacl -R -m g::rwx /opt/librenms/rrd /opt/librenms/logs /opt/librenms/bootstrap/cache/ /opt/librenms/storage/ /opt/librenms/cache
Install PHP dependencies
su - librenms
./scripts/composer_wrapper.php install --no-dev
exit
DB Server
Configure MySQL
systemctl enable --now mariadb
mysql -u root

NOTE: You need to change the ‘password’ below to something secure.

CREATE DATABASE librenms CHARACTER SET utf8 COLLATE utf8_unicode_ci;
CREATE USER 'librenms'@'localhost' IDENTIFIED BY 'password';
GRANT ALL PRIVILEGES ON librenms.* TO 'librenms'@'localhost';
FLUSH PRIVILEGES;
exit
vi /etc/my.cnf

Within the [mysqld] section add:

innodb_file_per_table=1
lower_case_table_names=0

systemctl restart mariadb
Web Server
Configure PHP

Ensure date.timezone is set in php.ini to your preferred time zone. See http://php.net/manual/en/timezones.php for a list of supported time zones. Valid examples are: “America/New_York”, “Australia/Brisbane”, “Etc/UTC”.

When PHP is configured with open_basedir, be sure to allow the following paths for LibreNMS to work:

php_admin_value[open_basedir] = "/opt/librenms:/usr/lib64/nagios/plugins:/dev/urandom:/usr/sbin/fping:/usr/sbin/fping6:/usr/bin/snmpgetnext:/usr/bin/rrdtool:/usr/bin/snmpwalk:/usr/bin/snmpget:/usr/bin/snmpbulkwalk:/usr/bin/snmptranslate:/usr/bin/traceroute:/usr/bin/whois:/bin/ping:/usr/sbin/mtr:/usr/bin/nmap:/usr/sbin/ipmitool:/usr/bin/virsh:/usr/bin/nfdump"
vi  /etc/php.ini

or

vi /etc/opt/rh/rh-php72/php.ini

Configure Apache

Create the librenms.conf:

vi /etc/httpd/conf.d/librenms.conf

Add the following config, edit ServerName as required:

<VirtualHost *:80>
  DocumentRoot /opt/librenms/html/
  ServerName  librenms.actsupport.com
  AllowEncodedSlashes NoDecode
  <Directory "/opt/librenms/html/">
    Require all granted
    AllowOverride All
    Options FollowSymLinks MultiViews
  </Directory>
</VirtualHost>

NOTE: If this is the only site you are hosting on this server (it should be : ) then you will need to disable the default site. rm -f /etc/httpd/conf.d/welcome.conf

systemctl enable --now httpd
SELinux

Install the policy tool for SELinux:

yum install policycoreutils-python

Configure the contexts needed by LibreNMS

semanage fcontext -a -t httpd_sys_content_t '/opt/librenms/logs(/.*)?'
semanage fcontext -a -t httpd_sys_rw_content_t '/opt/librenms/logs(/.*)?'
restorecon -RFvv /opt/librenms/logs/
semanage fcontext -a -t httpd_sys_content_t '/opt/librenms/rrd(/.*)?'
semanage fcontext -a -t httpd_sys_rw_content_t '/opt/librenms/rrd(/.*)?'
restorecon -RFvv /opt/librenms/rrd/
semanage fcontext -a -t httpd_sys_content_t '/opt/librenms/storage(/.*)?'
semanage fcontext -a -t httpd_sys_rw_content_t '/opt/librenms/storage(/.*)?'
restorecon -RFvv /opt/librenms/storage/
semanage fcontext -a -t httpd_sys_content_t '/opt/librenms/bootstrap/cache(/.*)?'
semanage fcontext -a -t httpd_sys_rw_content_t '/opt/librenms/bootstrap/cache(/.*)?'
restorecon -RFvv /opt/librenms/bootstrap/cache/
semanage fcontext -a -t httpd_sys_content_t '/opt/librenms/cache(/.*)?'
semanage fcontext -a -t httpd_sys_rw_content_t '/opt/librenms/cache(/.*)?'
restorecon -RFvv /var/www/opt/librenms/cache/
setsebool -P httpd_can_sendmail=1
Additional SELinux problems may be found by executing the following command
audit2why < /var/log/audit/audit.log
Allow fping

Create the file http_fping.tt with the following contents. You can create this file anywhere, as it is a throw-away file. The last step in this install procedure will install the module in the proper location.

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 };

Then run these commands

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
Allow access through firewall

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

Configure snmpd

Copy the example snmpd.conf from the LibreNMS install.

cp /opt/librenms/snmpd.conf.example /etc/snmp/snmpd.conf
vi /etc/snmp/snmpd.conf

Edit the text which says RANDOMSTRINGGOESHERE and set your own community string.

curl -o /usr/bin/distro https://raw.githubusercontent.com/librenms/librenms-agent/master/snmp/distro
chmod +x /usr/bin/distro
systemctl enable snmpd
systemctl restart snmpd
Cron job

cp /opt/librenms/librenms.nonroot.cron /etc/cron.d/librenms

Web installer:

Now head to the web installer and follow the on-screen instructions.

http://librenms.actsupport.com/install.php

The web installer might prompt you to create a config.php file in your librenms install location manually, copying the content displayed on-screen to the file.

chown librenms:librenms /opt/librenms/config.php

Final steps
That’s it! You now should be able to log in to http://librenms.actsupport.com/

Add the first device
We now suggest you to add localhost as your first device from within the WebUI.

Hope you successfully installed. Get assistance from RedHat/CentOS Linux professionals to install and troubleshoot your issues.

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