====== Setup Nagios ======

This Howto explains how to set up [[http://www.nagios.org/|nagios]], so you can monitor your server.

===== 1. Install the nagios package =====

At first, you have to install the nagios2 package:

  # apt-get update && apt-get install nagios2

===== 2. Create the necessary files and directories for the webinterface =====

You can't use the default apache-config-file which comes with nagios, because in ispCP, Websites have to be under /var/www.

So you have to create a directory there, **/var/www/nagios** and copy the contents of /usr/share/nagios2/htdocs into this directory.

  # mkdir -p /var/www/nagios/htdocs
  # cp -R /usr/share/nagios2/htdocs/* /var/www/nagios/htdocs/

This directory has to be owned by the www-data - User:

  # chown -R www-data.www-data /var/www/nagios


Now you can create a file **/etc/apache2/sites-available/nagios2.conf** with the following content:
  
  #
  # nagios Virtual Host Webinterface
  #
  
  <VirtualHost xxx.xxx.xxx.xxx:80>                           <-- insert your IP here
          ServerAdmin     admin@yourdomain.com               <-- insert your mail adress here
          DocumentRoot    /var/www/nagios/htdocs
  
          ServerName      nagios.yourdomain.com              <-- insert your domain here
  
          ErrorLog        /var/log/apache2/nagios.yourdomain.com-error.log  <-- dito
          CustomLog       /var/log/apache2/nagios.yourdomain.com-access.log combined  <-- dito
  
          ScriptAlias /cgi-bin/nagios2 /var/www/nagios/cgi-bin
          ScriptAlias /nagios2/cgi-bin /var/www/nagios/cgi-bin
  
          <Directory /var/www/nagios>
                  Options FollowSymLinks
  
                  DirectoryIndex index.html
  
                  AllowOverride AuthConfig
                  Order Allow,Deny
                  Allow From All
  
                  AuthName "Nagios Access"
                  AuthType Basic
                  AuthUserFile /etc/nagios2/htpasswd.users
                  require valid-user
          </Directory>
  
          <Directory "/usr/lib/cgi-bin/nagios2">
                  Options ExecCGI
  
                  AllowOverride None
                  Order allow,deny
                  Allow from all
  
                  AuthName "Nagios Access"
                  AuthType Basic
                  AuthUserFile /etc/nagios2/htpasswd.users
                  Require valid-user
          </Directory>
  
  </VirtualHost>

and enabled it via

  # a2ensite nagios2.conf

In order to be able to run a subdomain like //nagios.yourdomain.com// you have to edit the files **/etc/apache2/sites-available/ispcp.conf** and **/etc/ispcp/apache/working/ispcp.conf**, go to the vhost-section of //yourdomain.com// and delete the //*.yourdomain.com// in this line:

  ServerAlias     www.yourdomain.com yourdomain.com *.yourdomain.com

After all this, you have to reload the apache configuration:

  # /etc/init.d/apache2 reload

===== 3. Change the nagios configuration =====

In the file **/etc/nagios2/cgi.cfg** you have to change the values //physical_html_path// and //url_html_path// as shown below:

  physical_html_path=/var/www/nagios/htdocs
  url_html_path=/

===== 4. Create password file for nagios =====

Now you have to create a password file for nagios which has to be placed under **/etc/nagios2/htpasswd.users**:

  # htpasswd -c /etc/nagios2/htpasswd.users nagiosadmin
  New password:
  Re-type new password:

===== 5. Finished =====

Now, you should be able to access nagios via [[http://nagios.yourdomain.com]], login with the username **nagiosadmin** and the password specified under 4.

The nagios configuration is done under /etc/nagios2/, you find the nagios documentation here: [[http://nagios.sourceforge.net/docs/2_0/]]