Discrepancy between plugin-api documentation and how it actually does (not) work

Troubleshooting
1

CMK version: 2.5.0p11+
OS version: Debian13

Error message:

ValueError: cmk_addons.plugins.hp_msa.agent_based.hp_msa_controller:agent_section_hp_msa_controller: plug-in 'hp_msa_controller' already defined at cmk.plugins.hp_msa.agent_based.hp_msa_controller:agent_section_hp_msa_controller

Hello,

According to the plugin-api documentation https://docs.checkmk.com/plugin-api/latest/#the-shadowing-mechanism it is possible to override a complete family (“hp_msa” in my case) with placing an __init__.py in the family folder. The built-in checks are not ignored like the documentation states and produce errors in UI and CLI.

How should this be fixed?

Greetings
Stefan Mühling

2

You put your modification in the wrong folder.
Such modified built-in checks need to go to ~/local/lib/python3/cmk/plugins/…

3

Thanks for the hint with the folder. Now I see it and it works as expected.

4

I added a hint here:

Scroll down, the grey admonition. I hope, this will be seen by everyone looking for information on the overshadowing functionality.