Configure custom agent plugin in WATO and write to /etc/checkmk/my_plugin.cfg

HenriWahl · October 24, 2024, 12:15pm

Hello,

I am writing here after searching docs and The Web for a while now without result. So I try to find an answer here. The question is: how can I configure a custom plugin in WATO and bake certain config into an agent, so that this config will be placed in /etc/check_mk at the remote host?

In detail, I want to be able to set a variable KUBECONFIG file path in WATO and get it down onto the host. It should be read in checkmk-agent-plugin-kubernetes-namespaces/mkp/agents/plugins/kubernetes_namespaces.py at kubeadmin-var · HenriWahl/checkmk-agent-plugin-kubernetes-namespaces · GitHub.

Is this somehow possible or is there another way to get a config from WATO to the agent plugin?

Thanks for any hint - Henri

aeckstein · October 24, 2024, 8:36pm

Hi Henri,

yes, you can do that.
In 2.3 you can use the new bakery api to achieve that. The API Documentation can be found in you site in help - “Plugin API references”.

There is an example integration for different operating systems.
Further examples can be found in the checkmk exchange. I think e.g. the sslcertificates MKP by Robert does exactly that for linux systems.

HenriWahl · October 25, 2024, 6:15am

@aeckstein thanks for the hint! Basically this means on older setup with 2.2.0 there is no way to do so? I just found other configs like mk_inventory.cfg on the host in /etc/check_mk but did not find out how they got there. Maybe the are provided by core Checkmk.

andreas-doehler · October 25, 2024, 6:24am

The following Link shows a small example from one of my plugins with config file generation in 2.1.

github.com

Yogibaer75/Check_MK-Things/blob/master/check plugins 2.1/windows_patch_day/lib/check_mk/base/cee/plugins/bakery/windows_patch_day.py

#!/usr/bin/env python3
# -*- encoding: utf-8; py-indent-offset: 4 -*-

# (c) Andreas Doehler <andreas.doehler@bechtle.com/andreas.doehler@gmail.com>

# This 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 in version 2.  check_mk is  distributed
# in the hope that it will be useful, but WITHOUT ANY WARRANTY;  with-
# out even the implied warranty of  MERCHANTABILITY  or  FITNESS FOR A
# PARTICULAR PURPOSE. See the  GNU General Public License for more de-
# ails.  You should have  received  a copy of the  GNU  General Public
# License along with GNU Make; see the file  COPYING.  If  not,  write
# to the Free Software Foundation, Inc., 51 Franklin St,  Fifth Floor,
# Boston, MA 02110-1301 USA.

from pathlib import Path
from typing import Any, Dict

from .bakery_api.v1 import FileGenerator, OS, Plugin, PluginConfig, register

This file has been truncated. show original

This should also work the same way in 2.2.

aeckstein · October 25, 2024, 6:39am

Hi Henri,

it is also possible to do the same in checkmk 2.2.
You can look into /lib/python3/cmk/base/cee/plugins/bakery like
grep -r "yield PluginConfig" /opt/omd/versions/<your version>/lib/python3/cmk/base/cee/*

There are a lot examples how and what can be achieved.

I would also look into MKP packages in the checkmk Exchange where that problem has already been solved e.g. the ceph or the sslcertificates plugin.

If you only want to deploy the config you will need:

The valuespec definition to set the needed values with a rule - /web/plugins/wato/yourplugin.py
The bakery configuration to deploy the configuration file into the package - /lib/python3/cmk/base/cee/plugins/bakery/yourplugin.py

HenriWahl · November 5, 2024, 3:18pm

Thanks to all of you - your comments helped me to get the config done!

Sara · November 15, 2024, 5:05pm

Can you please mark the answer as the solution if it solved your problem?

system · November 15, 2025, 5:05pm

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