nomd nomitoring distribution

Generally, nomd is small and lightweight nomitoring distribution.
Specifically, nomd is no omd.

nomd is designed to be run once or twice a day via cron or every time you log in to your desktop. It can inform and warn you about various things, like that one partition that is nearly full again or that your ISP mail server is currently unreachable.

nomd is not designed to be deployed on a server farm with hundreds of systems and provide instant alerts, graphs and statistics. There are various other tools for this kind of scenario (but if you do look for a small and simple solution for some local statistic graphs, have a look at https://github.com/mmitch/rrd).

features

• very few dependencies
  • some usual shell commands
  • some Perl
• easy to install
  • clone the git repository and you're ready to go
  • run on demand or via cron
• simple configuration
  • it's just a shell script, no need to learn a new language
• maximum flexibility
  • configuration is just a shell script: use conditions, call external tools, everything is possible
• self documenting
  • nomdoc shows all available commands and explains their use
  • nomdep shows missing dependencies (binaries, Perl modules)
• no special privileges required
  • all default command should run as a normal user, no root needed

quick start

After cloning the repository, enter the nomd directory and run ./nomd to run the default configuration. If you run into problems or like to know more, read on.

basics

Note: All nomd operations expect your current working directory to be the root directory of the nomd installation.

nomd basically distinguishes two types of commands:

• checks are commands that execute various checks and return the status as a result

• notifications are commands that aggregate the generated status and present them to you in different ways

dependencies

nomd definitely needs

• bash 4 or later
• Perl 5.10 or later

All other dependencies can be listed by running ./nomdep. It will show missing dependencies together with the checks and notifications that depend on them so you can decide if you need that dependency or can live on without it.

Installing missing dependencies is up to you.

If you use the apt package manager, ./nomdep --apt tries to guess missing package names for you. This is quite wobbly, but might save you some searching and typing in simple cases.

If you use the pkg package manager, ./nomdep --pkg tries to guess missing package names for you. This is quite wobbly, but might save you some searching and typing in simple cases.

If you manage local Perl packages via cpanm, run ./nomdep --cpanm to print a command to install all missing Perl packages at once. The output should be usable for other Perl package managers, too.

documentation

Run ./nomdoc to show a list of all available checks and notifications.

Add an argument to show details about all checks and notifications that match the given argument (it's treated as a regular expression). ./nomdoc ^notify will list all notifications with their parameters.

configuration

nomd reads these configuration files:

• check.local contains the checks you want to run. It is a shell script, you can mostly do what you want, but you should not write to stdout as this is where the check results are collected.
• If check.local is missing, nomd falls back to check.default which contains an example configuration and is part of the nomd distribution.
• Likewise, notify.local contains the notifications you want to run. It is also shell script, but this time stdout can be used without restrictions.
• Again, if notify.local is missing, nomd falls back to notify.default which contains an example configuration and is part of the nomd distribution.

To get started with your own configuration, copy check.default and notify.default to check.local and notify.local and start hacking.

Both check.local and notify.local are not part of the git repository and will not be overwritten on updates.

advanced configuration

nomd currently passes all arguments to both the check and notify scripts. I often do something like this in my notify.local to allow quick testing of changes via ./nomd --test when nomd is normally just run daily via cron:

if [ "$1" = '--test' ]; then
    notify_stdout
else
    notify_mail
fi

custom checks and notifications

Have a look at the existing checks and notifications in the check/ and notify/ subdirectories and/or read PROTOCOL.md for a quick overview of some of the internals.

You can implement custom commands either directly in your check.local/notify.local or write a standalone command in the check/ and notify/ subdirectories.

If your standalone custom commands might be useful for other people, feel free to send me a pull request so they can be included in the nomd distribution :-)

running nomd

To start nomd, you must change into the installation directory and run ./nomd. Alternatively, you can run make or make run, but this does not allow you to pass parameters to your scripts.

nomd runs the configured checks, sends any notifications and exits.

irregular runs

On desktop systems a good way to run nomd would be on every logon. Depending in your system configuration, it could suffice to add this line to your ~/.xinitrc:

( cd git/nomd; ./nomd ) &

This will run nomd in the background so your login does not stall. It expects the nomd installation directory to be $HOME/git/nomd.

regular runs

Use a tool of your choice to run nomd regularly if your system is running continuously.

If you use cron, the following crontab entry would run nomd twice a day if your installation directory is $HOME/git/nomd:

0 5,17	* * *	cd git/nomd; ./nomd

updates

If you cloned the nomd repository, simply run git pull to get the latest changes. You can use the check_nomd_updates check to get informed when updates are available.

resources

Project homepage, git repository and bug tracker are available at https://github.com/mmitch/nomd

license

Copyright (C) 2017-2023 Christian Garbs mitch@cgarbs.de
Licensed under GNU GPL v3 or later.

nomd is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

nomd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with nomd. If not, see http://www.gnu.org/licenses/.