Postgresql built in plugin doesnt show up in discovery

CMK version: 2.2.0
OS version: Ubuntu 22.04

Error message: None

Ok. I’m at a loss here.
Let’s break this down.
I want to monitor a postgresql database on a linux host.
There exists a built-in plugin called mk_postgres.py.

I find the path to this file via Setup → Agents → Windows, Linux, Solaris, AIX
At the top I click Related → Linux, Solaris, AIX files

those steps alone took me an hour to figure out since getting there for the file paths isn’t documented anywhere I can find.

Now, how do I get the postgres plugin onto the host? That’s not documented anywhere either. Luckily I find this thread : How to monitoring postgres on linux with checkmk - General - Checkmk Community

Awesome, ok. Apparently I’m supposed to manually download this mk_postgres.py file into the the /usr/lib/check_mk_agent/plugins directory. (the thread had the wrong path, I can only assume it changed between Nov 2021 and now.

Ok, I’ve got the python file in the directory. Watching this video: Episode 35: Monitoring SQL databases with Checkmk - YouTube and it seems I need to do a service discovery after getting that python file on the client.

Except nothing happens after I do a service discovery. No additional services are discovered.
When I continue to search I find this thread: Mk_mongodb and mongodb_connections plugins not being discovered - Troubleshooting - Checkmk Community that shows me how to possibly troubleshoot to make sure the plugin is working locally by calling the python file.

So I run sudo python3 mk_postgres.py and I get tons of output on my client machine.

So that’s where I sit. I have no idea what is the proper procedure to make this stuff work. I’ve had to cobble together from 3 different sources to even get this far.

When I run service discovery from the web GUI the Check_MK Agent status detail keeps saying “Agent plugins: 0”

I’m at a loss how to move forward.

for anyone else that has this problem. I finally found some documentation that addresses this issue here: Monitoring Linux - The new agent for Linux in detail (checkmk.com)

The actual installation is then simple: Copy the file to /usr/lib/check_mk_agent/plugins. Make sure that it is executable. If not, use a chmod 755, otherwise the agent will not execute the plug-in. Note that especially if you do not transfer the files via scp but fetch them via HTTP from the download page, the execution permission will be lost.
Once the plug-in is executable and located in the correct directory, it will be automatically invoked by the agent and a new section will be created in the agent output.