Nagios is very lightweight monitoring tool. We are using this tool for past 1-2 years but somehow one day it get crash and to setup/restore Nagios it took more than 4hours(on premises). so rather than running it on a machine that itself was constantly crashing I decided to move it onto Amazon Web Services EC2 platform using the Free Tier Entitlement you get when you first sign up. Therefore total cost to me to move it from home to the cloud was $0, at least for the first 12 months and not taking into account time.
Below steps to install Nagios Core and get it running on an Amazon IaaS was known as an EC2 instance using the Amazon Linux AMI as a base OS.
To Start Nagios Core Installation you must have your EC2 instance up and run and have already configured SSH access to the instance.
These instructions will work equally well with Linux on a bare metal server running any Red Hat variety of Linux such as CentOS.
Step 1: Install Prerequisite Software
Nagios requires the following packages are installed on your server prior to installing Nagios:
* GCC compiler
* GD development libraries
You can use yum to install these packages by running the following commands (as ec2-user):
# sudo yum install httpd php
# sudo yum install gcc glibc glibc-common
# sudo yum install gd gd-devel
Step 2: Create Account Information
You need to setup a Nagios user. Run the following commands:
# sudo adduser -m nagios
# sudo passwd nagios
Type the new password twice.
# sudo groupadd nagcmd
# sudo usermod -a -G nagcmd nagios
# sudo usermod -a -G nagcmd apache
Step 3: Download Nagios Core and the Plugins
Create a directory for storing the downloads.
# mkdir ~/downloads
# cd ~/downloads
Download the source code tarballs of both Nagios and the Nagios plugins (visit http://www.nagios.org/download/ for links to the latest versions).
Step 4: Compile and Install Nagios
Extract the Nagios source code tarball.
# tar zxvf nagios-4.0.8.tar.gz
# cd nagios-4.0.8
Run the configure script with name of the group you created earlier
# ./configure –with-command-group=nagcmd
Compile the Nagios source code.
# make all
Install binaries, init script, sample config files and set permissions on the external command directory.
# sudo make install
# sudo make install-init
# sudo make install-config
# sudo make install-commandmode
Step 5: Customize Configuration
Change E-Mail address with nagiosadmin contact definition you’d like to use for receiving Nagios alerts.
# sudo vim /usr/local/nagios/etc/objects/contacts.cfg
Step 6: Configure the Web Interface
# sudo make install-webconf
Create a nagiosadmin account for logging into the Nagios web interface. Remember the password you assign to this account – you’ll need it later.
# sudo htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin //Type the new password twice.
# sudo service httpd restart //Restart Service
Step 7: Compile and Install the Nagios Plugins
Extract the Nagios plugins source code tarball.
# cd ~/downloads
# tar zxvf nagios-plugins-2.0.3.tar.gz
# cd nagios-plugins-2.0.3
Compile and install the plugins.
# ./configure –with-nagios-user=nagios –with-nagios-group=nagios
# sudo make install
Step 8: Start Nagios
Add Nagios to the list of system services and have it automatically start when the system boots.
# sudo chkconfig –add nagios
# sudo chkconfig nagios on
Verify the sample Nagios configuration files.
# sudo /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
If there are no errors, start Nagios.
# sudo service nagios start
Step 9: Update AWS Security Group
you need to open port 80 on the new AWS EC2 server to incoming traffic so you can connect to the new Nagios webpage.
* From the EC2 console select Security Groups from the left navigation pane.
* Select the Security Group applicable for the instance that Nagios was installed on and open the Inbound tab
* If there is no rule to allow HTTP traffic on port 80 then click edit in the Inbound tab to add a new rule
* Click on New Rule button
* Scroll down to select HTTP from the list of Type
* If you want to be able to access Nagios from anywhere then select Save, otherwise enter the IP address or range of IP address you want to be able to access it from then select Save.
Step 10: Login to the Web Interface
access the Nagios web interface to do this you will need to know the Public DNS or IP for your instance, you can get this from the Instance section of the EC2 Console if you do not already know it. You’ll be prompted for the username (nagiosadmin) and password you specified earlier.