Nagios Installation in Ubuntu
Required Packages
Install the following packages on Ubuntu before continuing.
- Apache 2
- PHP
- GCC compiler and development libraries
- GD development libraries
If not installed, using apt-get the above packages can be installed as follows
- sudo apt-get install apache2
- sudo apt-get install libapache2-mod-php5
- sudo apt-get install build-essential
- sudo apt-get install libgd2-xpm-dev
Create Account Information
- Become the root user.
sudo -s
- Create a new nagios user account and give it a password.
/usr/sbin/useradd -m -s /bin/bash nagios
passwd nagios
- Create a new nagcmd group for allowing external commands to be submitted through the web interface. Add both the nagios user and the apache user to the group.
/usr/sbin/groupadd nagcmd
/usr/sbin/usermod -a -G nagcmd nagios
/usr/sbin/usermod -a -G nagcmd www-data
Download Nagios and the Plugins
Create a directory for storing the downloads.
- mkdir /opt/downloads
- cd /opt/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).
- wget -c http://prdownloads.sourceforge.net/sourceforge/nagios/nagios-3.2.0.tar.gz
- wget -c http://prdownloads.sourceforge.net/sourceforge/nagiosplug/nagios-plugins-1.4.11.tar.gz
Compile and Install Nagios
Extract the Nagios source code tarball.
- cd /opt/downloads
- tar xzvf nagios-3.2.0.tar.gz
- cd nagios-3.2.0
Run the Nagios configure script, passing the name of the group you created earlier like so:
- ./configure –with-command-group=nagcmd
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
General Options:
————————-
Nagios executable: nagios
Nagios user/group: nagios,nagios
Command user/group: nagios,nagcmd
Embedded Perl: no
Event Broker: yes
Install ${prefix}: /usr/local/nagios
Lock file: ${prefix}/var/nagios.lock
Check result directory: ${prefix}/var/spool/checkresults
Init directory: /etc/init.d
Apache conf.d directory: /etc/apache2/conf.d
Mail program: /usr/bin/mail
Host OS: linux-gnu
Web Interface Options:
————————
HTML URL: http://localhost/nagios/
CGI URL: http://localhost/nagios/cgi-bin/
Traceroute (used by WAP):
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
You can continue with installing Nagios as follows (type ‘make’
without any arguments for a list of all possible options):
make install-init
– This installs the init script in /etc/init.d
make install-commandmode
– This installs and configures permissions on the
directory for holding the external command file
make install-config
– This installs sample config files in /usr/local/nagios/etc
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- sudo make install-init
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/install -c -m 755 -d -o root -g root /etc/init.d
/usr/bin/install -c -m 755 -o root -g root daemon-init /etc/init.d/nagios
*** Init script installed ***
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- sudo make install-config
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/install -c -m 775 -o nagios -g nagios -d /usr/local/nagios/etc
/usr/bin/install -c -m 775 -o nagios -g nagios -d /usr/local/nagios/etc/objects
/usr/bin/install -c -b -m 664 -o nagios -g nagios sample-config/nagios.cfg /usr/local/nagios/etc/nagios.cfg
/usr/bin/install -c -b -m 664 -o nagios -g nagios sample-config/cgi.cfg /usr/local/nagios/etc/cgi.cfg
/usr/bin/install -c -b -m 660 -o nagios -g nagios sample-config/resource.cfg /usr/local/nagios/etc/resource.cfg
/usr/bin/install -c -b -m 664 -o nagios -g nagios sample-config/template-object/templates.cfg /usr/local/nagios/etc/objects/templates.cfg
/usr/bin/install -c -b -m 664 -o nagios -g nagios sample-config/template-object/commands.cfg /usr/local/nagios/etc/objects/commands.cfg
/usr/bin/install -c -b -m 664 -o nagios -g nagios sample-config/template-object/contacts.cfg /usr/local/nagios/etc/objects/contacts.cfg
/usr/bin/install -c -b -m 664 -o nagios -g nagios sample-config/template-object/timeperiods.cfg /usr/local/nagios/etc/objects/timeperiods.cfg
/usr/bin/install -c -b -m 664 -o nagios -g nagios sample-config/template-object/localhost.cfg /usr/local/nagios/etc/objects/localhost.cfg
/usr/bin/install -c -b -m 664 -o nagios -g nagios sample-config/template-object/windows.cfg /usr/local/nagios/etc/objects/windows.cfg
/usr/bin/install -c -b -m 664 -o nagios -g nagios sample-config/template-object/printer.cfg /usr/local/nagios/etc/objects/printer.cfg
/usr/bin/install -c -b -m 664 -o nagios -g nagios sample-config/template-object/switch.cfg /usr/local/nagios/etc/objects/switch.cfg
*** Config files installed ***
Remember, these are *SAMPLE* config files. You’ll need to read
the documentation for more information on how to actually define
services, hosts, etc. to fit your particular needs.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- sudo make install-commandmode
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/install -c -m 775 -o nagios -g nagcmd -d /usr/local/nagios/var/rw
chmod g+s /usr/local/nagios/var/rw
*** External command directory configured ***
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Don’t start Nagios yet – there’s still more that needs to be done…
Nagios Configuration
Sample Configuration files are available in the path
- /usr/local/nagios/etc/
- /usr/local/nagios/etc/objects/
a) Configuration1: Basic Contact Info
The first components to set up are contacts and contact groups.
Contacts are people who receive notifications when a host or service is down. Nagios offers pager and e-mail notifications by default.
Contacts are stored in the /usr/local/nagios/etc/objects/contacts.cfg file and are defined as follows:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~“
define contact{
contact_name gama ; Short name of user
use generic-contact ; Inherit default values from generic-contact template (defined in templates.cfg) – Commented out
alias Nagios Admin ; Full name of user
email gama@actsupport.com ; <<***** CHANGE THIS TO YOUR EMAIL ADDRESS ******
}
define contactgroup{
contactgroup_name admins
alias Nagios Administrators
members rama
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Create the following files – hosts.cfg and hostgroups.cfg. From the templates.cfg file, we shall get he template definitions for server “linux-server”
b) sudo vi /usr/local/nagios/etc/objects/hosts.cfg (new config file)
For every host added for monitoring, an entry needs to be put in the hosts.cfg file. An example is illustrated below, for host 10.10.36.199
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
define host{
host_name EastColo-TestWeb
use linux-server
alias East Colo Test Web
address 10.10.36.199
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
c) sudo vi /usr/local/nagios/etc/objects/hostgroups.cfg
The host added in hosts.cfg must be made part of a hostgroup. For example, the host 10.10.36.199, is being made part of hostgroup, TestWeb. We can add as many hosts we want in a hostgroup. Each hostgroup member need to be seperated by a comma(,).
define hostgroup {
hostgroup_name TestWeb
alias Test Web Servers
members EastColo-TestWeb,WestColo-TestWeb
}
d) Now according to the service to be monitored for each host, an entry for each host or hostgroup need to be made in /usr/local/nagios/etc/objects/localhost.cfg.
define service{
use local-service ; Name of service template to use
host_name localhost
hostgroup_name TestWeb
service_description PING
check_command check_ping!100.0,20%!500.0,60%
}
e) Edit the main configuration file, “nagios.cfg” under the directory /usr/local/nagios/etc/
Add the lines
cfg_file=/usr/local/nagios/etc/objects/hosts.cfg
cfg_file=/usr/local/nagios/etc/objects/hostgroups.cfg
f) Check if the Nagios Configuration files are ok, using the command
sudo /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
Configure the Web Interface – Apache Configuration
a) cd /opt/downloads/nagios-3.2.0
b) Install the Nagios web config file in the Apache conf.d directory.
sudo make install-webconf
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/install -c -m 644 sample-config/httpd.conf /etc/apache2/conf.d/nagios.conf
*** Nagios/Apache conf file installed ***
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
c) 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 nagadmin
d) Restart Apache
$ sudo /etc/init.d/apache2 reload
Compile and Install the Nagios Plugins
—————————————–
- cd /opt/downloads/nagios-3.2.0
- tar xzvf nagios-plugins-1.4.11.tar.gz
- cd nagios-plugins-1.4.11
- ./configure –with-nagios-user=nagios –with-nagios-group=nagios
- make
- sudo make install
This will install all the nagios plugin scripts under the path “/usr/local/nagios/libexec“
Configure Nagios to automatically start when the system boots
- ln -s /etc/init.d/nagios /etc/rcS.d/S99nagios
Start Nagios
a) Verify the configuration files of Nagios
- sudo /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
b) If there are no errors, start Nagios.
- sudo /etc/init.d/nagios start
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