Quickstart for Nagios + check_mk on Debian 5.0 (Lenny)
-----------------------------------------------------------

This guide tells you how to set up Nagios and check_mk
on Debian 5.0.

PART 1 : SETUP OF NAGIOS
========================

Install the Nagios3 package from the distribution:

# aptitude install nagios3

Nagios3 and Apache2 are running now. Now Setup a password for the
Webinterface:

# htpassswd3 /etc/nagios3/htpasswd.users nagiosadmin
New password: SECRET
Retype new password: SECRET
Adding password for user nagiosadmin

You can log into the Webinterface to http://localhost/nagios3/
now with user 'nagiosadmin' and password 'SECRET'.

Now configure Nagios to allow external commands and allow
Apache to send those commands. First edit /etc/nagios3/nagios.cfg
and set check_external_commands=1. After setup permissions:

# chmod g+rx /var/lib/nagios3/rw
# usermod -aG nagios www-data

You need to restart Apache2 in order to get the new group:

# /etc/init.d/apache2 restart

Part 2: SETUP OF CHECK_MK
=========================
Nagios is now ready. Let's now install check_mk. First we
need xinetd (for the local agent):

# aptitude install xinetd

Now install the two .deb-packages of check_mk (one for the
Server, one for the local agent):

# dpkg -i check-mk-agent_1.0.26-2_all.deb
# dpkg -i check-mk_1.0.26-2_all.deb

You can test the local agent by telnetting to port 6556.
You should get the text output of the agent:

# telnet localhost 6556

After that we can setup localhost as the first host to be monitored
with check_mk. Configuration is done in /etc/check_mk:

# cd /etc/check_mk

Edit the example main.mk and add localhost to the
list of hosts:

all_hosts = [ 'localhost' ]

Also define the path to the Nagios command pipe:

nagios_command_pipe_path = '/var/lib/nagios3/rw/nagios.cmd'

Now you can inventurize localhost by calling check_mk with
the option -I:

# check_mk -I alltcp localhost

check_mk should find a couple of items to be monitored.
Now we need to complete the configuration of Nagios.
First we need a configuration file defining templates
for check_mk. A working sample is in /usr/share/doc/check_mk.
You can copy it verbatim to the Nagios configuration directory:

# cp /usr/share/doc/check_mk/check_mk_templates.cfg /etc/nagios3/conf.d/

The configuration files for the newly inventurized localhost
is generated automatically by combining the options -H and -S:

# check_mk -HS > /etc/nagios3/conf.d/check_mk_data.cfg

The last we have to do is to delete the sample configuration
for localhost prepackaged in the Debian Nagios package:

# rm /etc/nagios3/conf.d/localhost_nagios2.cfg

Finished. Restart Nagios. As soon as the host is checked
you'll enjoy the results in the Web interface.

# /etc/init.d/nagios3 restart