Nagios is the most widely used open source monitoring tools which help us to monitor the services and application that run’s on Windows,Linux,Routers and other network devices. With the help of Nagios you can monitor basic services and attributes. We can access the Nagios using web interface coming with the bundle and configuration need to be done on the file level.
- Core Workers are lightweight process whose job is to perform checks, due to this they do perform checks much more quickly than the old process.
- Nagios Core process using in-memory techniques, eliminating the disk I/O latencies that could previously slow things down in large installation.
- Each configuration item is verified only once.
- The host address attribute is now optional.
- Bothe hosts and services now supports an hourly value attribute.
More feature can be found here.
This Tutorial describes how can you monitor “private” services and attributes of Linux/UNIX servers, such as:
- CPU load
- Memory usage
- Disk usage
- Logged in users
- Running processes
Switch to root user.
Install the dependencies for Nagios 4.
apt-get update apt-get install build-essential apache2 php5 openssl perl make php5-gd libgd2-xpm-dev libapache2-mod-php5 libperl-dev libssl-dev daemon wget apache2-utils
Create nagios user and nagcmd group (allowing the external commands to be executed through the web interface) , add the nagios and apache user to the part of nagcmd group.
useradd nagios groupadd nagcmd usermod -a -G nagcmd nagios usermod -a -G nagcmd www-data wget https://assets.nagios.com/downloads/nagioscore/releases/nagios-4.0.8.tar.gz tar -zxvf /tmp/nagios-4.0.8.tar.gz cd /tmp/nagios-4.0.7/
Compile and Install Nagios:
./configure --with-nagios-group=nagios --with-command-group=nagcmd --with-httpd_conf=/etc/apache2/sites-enabled/ make all make install make install-init make install-config make install-commandmode make install-webconf
Sample configuration files have now been installed in the /usr/local/nagios/etc directory. These sample files should work fine for getting started with Nagios. You’ll need to make just one change before you proceed…
Edit the /usr/local/nagios/etc/objects/contacts.cfg config file with your favorite editor and change the email address associated with the nagiosadmin contact definition to the address you’d like to use for receiving alerts.
Change the Email address field to receive the notification.
contact_name nagiosadmin ; Short name of userus
generic-contact ; Inherit default values from generic-contact template (defined above)
alias Nagios Admin ; Full name of useremail
email@example.com ; <<***** CHANGE THIS TO YOUR EMAIL ADDRESS ******
Configure Web Interface:
Create a nagiosadmin account for logging into the Nagios web interface. Remember the password you assign to this account – you’ll need it later.
htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin
Run the following command.
Restart Apache to make the new settings take effect.
Download and Install Nagios Plugins:
Download Nagios Plugins to /tmp directory.
cd /tmp wget http://nagios-plugins.org/download/nagios-plugins-2.0.3.tar.gz tar -zxvf /tmp/nagios-plugins-2.0.3.tar.gz cd /tmp/nagios-plugins-2.0.3/
Compile and install the plugins.
./configure --with-nagios-user=nagios --with-nagios-group=nagios make make install
Verify the sample Nagios configuration files.
If there are no errors, start Nagios.
Access Web Interface:
Now access the Nagios web interface using the following URL. You’ll be prompted for the username (nagiosadmin) and password you specified earlier.