LibreNMS not able to ping device and can’t change device name

If your having issues in the LibreNMS web interface changing a devices IP address or you can’t add a new one because it says it can’t ping the device, it is probably because SELinux is causing issues.

As far as changing a devices ip address, it looks like SELinux is not allowing Apache write access to the /opt/librenms/rrd directory

Temporary fix is to run

setenforce 0

You can permenatly disable SElinux by opening up “/etc/selinux/config” and changing “SELINUX=enforcing” to “SELINUX=disabled” and rebooting.

 

Renaming of x.x.x.x failed . Does your web server have permission to modify the rrd files?

It looks like there may be a bug where you’ll try to change the IP of a device and get the above error.  It looks like the issue has something to do with the ip address.  If your trying to change the IP on a router that has multiple IP addresses, try a different address in LibreNMS.

 

Install LibreNMS on Ubuntu with HTTPS

The goal of this guide is to install LibreNMS on an Ubuntu Server with a self signed certificate.  Most of the steps are copied out of the LibreNMS Documentation found here.

Install required packages

sudo apt install apache2 composer fping git graphviz imagemagick libapache2-mod-php7.0 mariadb-client mariadb-server mtr-tiny nmap php7.0-cli php7.0-curl php7.0-gd php7.0-json php7.0-mcrypt php7.0-mysql php7.0-snmp php7.0-xml php7.0-zip python-memcache python-mysqldb rrdtool snmp snmpd whois

Create LibreNMS user

sudo useradd librenms -d /opt/librenms -M -r
sudo usermod -a -G librenms www-data

Install LibreNMS

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

Configure MySQL

sudo systemctl restart mysql
sudo mysql -uroot -p

Run the following MySQL commands to create the LibreNMS user. Change password to your own password.

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

Edit following file

sudo vi /etc/mysql/mariadb.conf.d/50-server.cnf

Add the following inside the [mysqld] section

innodb_file_per_table=1
sql-mode=""
lower_case_table_names=0

Restart MySQL

sudo systemctl restart mysql

Configure PHP

Edit the two files and set the time zone, date.timezone.  Example “America/New_York”

sudo vi /etc/php/7.0/apache2/php.ini
sudo vi /etc/php/7.0/cli/php.ini

Then run these commands

sudo a2enmod php7.0
sudo a2dismod mpm_event
sudo a2enmod mpm_prefork
sudo phpenmod mcrypt

Generate Self signed certificate

Enable ssl in apache

sudo a2enmod ssl

Generate Cert

sudo openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout /etc/ssl/private/localhost.key -out /etc/ssl/certs/localhost.crt

Configure Apache

Edit the following config file

sudo vi /etc/apache2/sites-available/librenms.conf

Add the following

<VirtualHost *:443>
 DocumentRoot /opt/librenms/html/
 ServerName librenms.example.com
 SSLEngine on
 SSLCertificateFile /etc/ssl/certs/localhost.crt
 SSLCertificateKeyFile /etc/ssl/private/localhost.key
 CustomLog /opt/librenms/logs/access_log combined
 ErrorLog /opt/librenms/logs/error_log
 AllowEncodedSlashes NoDecode
 <Directory "/opt/librenms/html/">
 Require all granted
 AllowOverride All
 Options FollowSymLinks MultiViews
 </Directory>
</VirtualHost>

Run the following commands

sudo a2ensite librenms.conf
sudo a2enmod rewrite
sudo systemctl restart apache2

Configure snmpd

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

Set the SNMP community string in the following file

sudo vi /etc/snmp/snmpd.conf

Then run these commands

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

Setup Crontab

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

Copy logrotate config

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

Set permissions

mkdir -p /opt/librenms/rrd /opt/librenms/logs
sudo chown -R librenms:librenms /opt/librenms
sudo setfacl -d -m g::rwx /opt/librenms/rrd /opt/librenms/logs
sudo setfacl -R -m g::rwx /opt/librenms/rrd /opt/librenms/logs

Web Installer

Restart apache

sudo systemctl restart apache2

Finish the install by going to

https://your-server/install.php

Change “your-server” to your server’s ip address, or hostname.  Since we created a self signed certificate, you’ll need to accept the https error.

Validate

Back on the command line run the php validation script

sudo /opt/librenms/validate.php

Finally log into your new LibreNMS instance by going to

https://your-server

Change “your-server” to your server’s IP address or hostname.

Optimizations for LibreNMS

Optimizations for fping.  Add to the LibreNMS config in “/opt/librenms/config.php”

$config['fping_options']['retries'] = 5;
$config['fping_options']['timeout'] = 1000;
$config['fping_options']['count'] = 4;
$config['fping_options']['millisec'] = 1000;

 

Use sysname instead of ip.  Add to the LibreNMS config in “/opt/librenms/config.php”

$config['force_ip_to_sysname'] = true;

 

Add device name to alert message.  Add to the alert templates template to show device name in alert.

%sysName\r\n