Category Archives: Nagios

Linux, Nagios

Compiling and using mk_livestatus on Nagios4 on Debian 10/Buster

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Prerequisites (other than the nagios4 packages, of course!):

# apt install rrdtool-dev librrd-dev librrd8 libboost-dev libboost-system-dev

Get latest source from https://checkmk.com/download-source.php, at time of writing, https://checkmk.com/support/1.5.0p23/mk-livestatus-1.5.0p23.tar.gz and unpack

# wget https://checkmk.com/support/1.5.0p23/mk-livestatus-1.5.0p23.tar.gz
# tar -zxvf mk-livestatus-1.5.0p23.tar.gz
# cd mk-livestatus-1.5.0p23

Configure for nagios4, compile and install

# ./configure --with-nagios4 --prefix=/usr/local/nagios && make install

Enable the broker module in Nagios4 – add this to, eg, your nagios.cfg – first make sure that this is set to send all events to the broker:

event_broker_options=-1

Then configure the broker_module – here, telling it to create the socket for livestatus at /var/lib/nagios4/rw/livestatus

broker_module=/usr/local/lib/mk-livestatus/livestatus.o /var/lib/nagios4/rw/livestatus

Now you can restart Nagios4 and test that the livestatus socket is working

# systemctl restart nagios4

# echo "GET status" | /usr/local/bin/unixcat /var/lib/nagios4/rw/livestatus

And you should get something like this:

accept_passive_host_checks;accept_passive_service_checks;cached_log_messages;check_external_commands;check_host_freshness;check_service_freshness;connections;connections_rate;enable_event_handlers;enable_flap_detection;enable_notifications;execute_host_checks;execute_service_checks;external_command_buffer_max;external_command_buffer_slots;external_command_buffer_usage;external_commands;external_commands_rate;forks;forks_rate;host_checks;host_checks_rate;interval_length;last_command_check;last_log_rotation;livecheck_overflows;livecheck_overflows_rate;livechecks;livechecks_rate;livestatus_active_connections;livestatus_queued_connections;livestatus_threads;livestatus_version;log_messages;log_messages_rate;mk_inventory_last;nagios_pid;neb_callbacks;neb_callbacks_rate;num_hosts;num_services;obsess_over_hosts;obsess_over_services;process_performance_data;program_start;program_version;requests;requests_rate;service_checks;service_checks_rate
1;1;0;1;0;1;1;0;1;1;1;1;1;0;0;0;0;0;0;0;57;0.416507;60;0;0;0;0;0;0;1;0;10;1.5.0p23;45;0.0199066;0;4310;1651;11.9169;83;467;0;0;0;1581514195;4.3.4;1;0;348;3.15754
Debian, Linux, Nagios

Tips for Configuring Nagios3 Efficiently – part 1

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Back when I started using Nagios (I think ~1.2 or earlier) I don’t remember many options for being all that efficient in terms of “lines of config written” – certainly, any options for being efficient that there may have been ended up being overlooked in the rush to get it up and running, and I’ve been largely been using the same configuration files (and style) ever since – though I did start using host and service templates as soon as I became aware of them some time back in the 2.x branch days.

In the spirit of self-improvement, I’ve been revisiting the Nagios configuration syntax as part of rolling out a fresh monitoring host based on Nagios3, and have significantly reduced the number of lines of config my Nagios installation depends on as a result.

Continue reading Tips for Configuring Nagios3 Efficiently – part 1 →

Debian, Linux, Nagios

Installing Nagios3 on Debian Wheezy

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It’s pretty straightforward to install Nagios on a Debian system but if you want to be able to use the web interface to control the nagios process a little more work is required.

Starting with a blank slate (apt/dpkg will ensure any required prerequisites will be installed):

# apt-get install nagios3 apache2-suexec

You’ll be asked to set a password for the nagiosadmin user for the web interface.

Enable check_external_commands in Nagios to enable the ability to mute alarms, make comments, restart the nagios process etc from the web interface (pretty much invaluable, but be aware of the inherent risks in enabling the ability to influence the process from “outside”)

# sed -i -e 's/check_external_commands=0/check_external_commands=1/' /etc/nagios3/nagios.cfg
# /etc/init.d/nagios3 restart

Edit the nagios3 apache2 config include to make the web interface scripts run as the nagios user so that the web interface can write to the nagios command pipe; inserting the following at the top of /etc/nagios3/apache2.conf:

User nagios
Group nagios

Restart apache..

# /etc/init.d/apache2 restart

And you’re pretty much done! You can go to http://YOUR_HOST_NAME/nagios3/ and log in with your nagiosadmin password you set up when prompted at the start of this process.

Now, you can get started with creating host and service configuration files in /etc/nagios3/conf.d/ to monitor your servers/network/etc