Munin is a network/system monitoring application that presents output in graphs through a web interface. If you haven't installed it already, use this tutorial: Monitoring multiple servers with Munin.

Assuming you have both varnish and munin installed, here's a tutorial on installing a plugin for munin to monitor Varnish.

1. Install git-core to receive the plugin from github

apt-get install git-core


2. cd into the munin plugins directory

/usr/share/munin/plugins


3. Download the munin-varnish plugin

git clone git://github.com/basiszwo/munin-varnish.git


4. Set correct permissions

chmod a+x /usr/share/munin/plugins/munin-varnish/varnish_*


5. Link the plugin sections to the munin config

ln -s /usr/share/munin/plugins/munin-varnish/varnish_* /etc/munin/plugins/


6. Add these lines to the bottom of the munin-node config (pico /etc/munin/plugin-conf.d/munin-node)

[varnish*]
user root


7. Restart munin-node

/etc/init.d/munin-node restart


1. Install Apache2, MySql server and PHP5 with required modules. You may already have some or all of these packages installed.

apt-get install apache2 php5-cli php5 mysql-server libdbd-mysql-perl php5-gd php5-mysql libapache2-mod-php5


2. Download the latest version of MailWatch

wget http://downloads.sourceforge.net/project/mailwatch/mailwatch/1.0.5/mailwatch-1.0.5.tar.gz


At the time this tutorial was written, version 1.0.5 was the latest version. Check this location for latest version: http://sourceforge.net/projects/mailwatch/files/

3. Extract and enter the mailwatch directory

tar zxvf mailwatch-1.0.5.tar.gz
cd mailwatch-1.0.5


4. Create the database and tables

mysql -p < create.sql


5. Create a MySql user used for MailScanner logging (mysql -u root -p)

GRANT ALL ON mailscanner.* TO '{username}'@'localhost' IDENTIFIED BY '{password}';
FLUSH PRIVILEGES;


Replace {username} and {password} with a username and password of choice.

6. Configure the MailScanner logger (pico MailWatch.pm)

my($db_user) = '{username}';
my($db_pass) = '{password}';


On line 43 and 44, input your MySql user created in step 5

7. Move the MailScanner logger to correct directory

mv MailWatch.pm /usr/share/MailScanner/MailScanner/CustomFunctions/


8. Edit Mail Scanner config to enable MailWatch logger (pico /etc/MailScanner/MailScanner.conf)

Always Looked Up Last = &MailWatchLogging


9. Create a MailWatch web admin user (mysql -u root -p)

USE mailscanner;
INSERT INTO users VALUES ('{username}',md5('{password}'),'Administrator name','A','0','0','0','0','0');


Replace {username} and {password} with a username and password used to enter the web interface.

10. Move the web interface to the web server's root

mv mailscanner /var/www/mailwatch


11. Make the temp and cache directories writeable

chmod 777 /var/www/mailwatch/temp
chmod 777 /var/www/mailwatch/images/cache


12. Copy the example config file

mv /var/www/mailwatch/conf.php.example /var/www/mailwatch/conf.php


13. Configure the web interface (pico /var/www/mailwatch/conf.php)

define('DB_USER', '{username}');
define('DB_PASS', '{password}');
define('MAILWATCH_HOME', '/var/www/mailscanner');


Type the MySql username and password created in step 5

14. Install PEAR PHP framework

apt-get install php-pear


15. Install required PEAR packages

pear install DB
pear install DB_Pager
pear install Mail_mimeDecode


16. On line 37, add /usr/share/php to the mailwatch include path (pico /var/www/mailwatch/functions.php)

ini_set('include_path','.:'.MAILWATCH_HOME.'/pear:'.MAILWATCH_HOME.'/fpdf:'.MAILWATCH_HOME.'/xmlrpc:/usr/share/php');


17. Restart Apache and MailScanner

/etc/init.d/apache2 restart
/etc/init.d/mailscanner restart


18. You're all set. Enter the web interface at this location http://yourserver/mailwatch

1. Install Cacti and all required packages

apt-get install cacti


You will be asked a few questions, here are some guidelines:

• Select a root password for MySql (only shown if you haven't installed MySql): [Type a new password]
• Webserver type: Apache2
• Configure database for cacti with dbconfig-common: yes
• Password of your database's administrative user: [Type a new password]
• MySQL application password for cacti: [Leave blank or type a new password]

2. Enter the web installation by going to this location in a web browser: http://yourserver/cacti

Replace yourserver with a host name or IP address of the server

Click Next -> Next -> Finish and accept the defaults to all steps.

3. In the login box use "admin" as both username and password.

You're all set, configuring Cacti is outside the scope of this tutorial but we'll probably cover than in another tutorial later.

The monitoring server

1. Install Nagios Core and dependancies

apt-get install nagios3 nagios-nrpe-plugin


2. Create the admin user

htpasswd -c /etc/nagios3/htpasswd.users nagiosadmin


3. Create a host to monitor (pico /etc/nagios3/conf.d/server1.cfg)

define host
{
use generic-host
host_name server1
alias server1
address 192.168.1.3
}
define service
{
use generic-service
host_name server1
service_description Disk Space
check_command check_all_disks!20%!10%
}
define service
{
use generic-service
host_name server1
service_description Current Users
check_command check_users!20!50
}
define service
{
use generic-service
host_name server1
service_description Total Processes
check_command check_procs!250!400
}

define service
{
use generic-service
host_name server1
service_description Current Load
check_command check_load!5.0!4.0!3.0!10.0!6.0!4.0
}


Replace server1 with the actual hostname of the server being monitored and the IP address to correct one.

This configuration will allow you to monitor the disk usage, active users, number of processes and the cpu load of a single server. Configuring host groups and other services are outside the scope of this article.

4. Restart Nagios

/etc/init.d/nagios3 restart


4. Enter the webadmin by opening this location in a web browser: http://yourserver/nagios3

Clients monitored by the monitoring server

1. Install the Nagios NRPE (Nagios Remote Plugin Executor)

apt-get install nagios-nrpe-server


2. Allow the monitoring server to connect to this NRPE (pico /etc/nagios/nrpe.cfg)

allowed_hosts=192.168.1.2


Replace 192.168.1.2 with the IP address of the monitoring server.

NRPE listens for connections on TCP port 5666 so make sure your firewall allows connections to that port from the monitoring server.

3. Restart NRPE

/etc/init.d/nagios-nrpe-server restart


ntop users can use a a web browser (e.g. netscape) to navigate through ntop (that acts as a web server) traffic information and get a dump of the network status. In the latter case, ntop can be seen as a simple RMON-like agent with an embedded web interface.

1. Install required packages

apt-get install ntop


2. Set administrator password

ntop --set-admin-password


3. Configure ntop to use your correct network adapter if it's not eth0 (optional)

dpkg-reconfigure ntop
> eth0 (or your network adapter)
> ntop


4. Start ntop

/etc/init.d/ntop start


Now you can access ntop web admin on a location similar to this one: http://192.168.1.100:3000. Just make sure you replace the IP address with your server IP address.

Before you install, make sure you have Apache web server installed.

1. Install hobbit packages

apt-get install hobbit hobbit-client hobbit-plugins


2. By default hobbit only allows connections from local host. Append the IP addresses you want to allow here in all three of the Allow from[...] lines like shown here (pico /etc/apache2/conf.d/hobbit)

Allow from localhost ::1/128 192.168.1.2


In this case I have added the 192.168.1.2 but you should replace it to the one on your computer

3. Create a user to access the administration section

htpasswd -c /etc/hobbit/hobbitpasswd {username}


4. Restart apache

/etc/init.d/apache2 restart


Now you can access the hobbit monitoring console on this location http://youservername/hobbit/ (Make sure you include the trailing slash)

Master monitoring server

1. Install Munin and Munin node daemon:

apt-get install munin munin-node


2. Configure server being monitored (pico /etc/munin/munin.conf):

[host.domain.com]
address xxx.xxx.xxx.xxx
use_node_name yes


Replace host.domain.com with the server's fully qualified domain and xxx.xxx.xxx.xxx with it's IP address. Type this code for each and every server being monitored including the master server.

3. Configure the Munin node daemon (pico /etc/munin/munin-node.conf).

Set the master server host name (Must be the same as used in /etc/munin/munin.conf):

host_name host.domain.com


4. Restart Munin node daemon:

/etc/init.d/munin-node restart


All other servers being monitored

1. Install Munin and Munin node daemon:

apt-get install munin munin-node


2. Configure the Munin node daemon (pico /etc/munin/munin-node.conf).

Set this server's host name (Must be the same as used in /etc/munin/munin.conf on the master server):

host_name host.domain.com


Allow the master server to connect and grab data:

allow ^xxx\.xxx\.xxx\.xxx$


Replace ^xxx\.xxx\.xxx\.xxx$ with your server's IP address. For example if the master server's IP address is 192.168.1.1, you would use: ^192\.168\.1\.1$. The master server will connect to this server on port 4949 so make sure that port isn't blocked on firewalls.

3. Restart Munin node daemon:

/etc/init.d/munin-node restart


Start by adding a zenoss entry to your apt sources (pico /etc/apt/sources.list):

deb http://dev.zenoss.org/deb main stable


Update apt repository

apt-get update


Install Zenoss and depending packages

apt-get install zenoss-stack


Start Zenoss

/etc/init.d/zenoss-stack start


You can now login by navigating to http://yourhost:8080/ using the username: admin and password: zenoss