CheckMK server on Docker

General
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1

Hi, I just installed the server on Docker. It runs well, but when I login, I only see the typical:
“As soon as you add your Checkmk server to the monitoring, a graph showing the history of your host problems will appear here. Please also be aware that you might see this message might appear as a result of a filtered dashboard. This dashlet currently only supports filtering for sites. Please refer to the [Checkmk user guide] (Dashboards) for more details.”
Well, when I had it on my Ubuntu machine, I just installed the agent, and it will populate.
How does it work as a Docker container?

Cheers

2

You need to monitor the Docker host, the Checkmk container is running on.
The Checkmk agent will pick up the necessary data from the container.

3

Hi, thanks for the info, but I already installed the agent on the docker host. Is there some setting I need to adjust?

4

I forgot to mention, that you need to roll out the docker plugin to the agent, so the agent within the container will be triggered: Monitoring Docker.

5

Hi,

Please, I’m a bit confuse, so Do I have to install two agents? (one for the local host and anohter one for the checkmk guest server in the container)

BR

6

No, just one agent on the docker host with the docker plugin enabled.

7

I did that when I installed the agent. Followed the video guide on Youtube.

2023-08-22 12_30_15-Checkmk Local site cmk - Services of Host Docker - Brave
2023-08-22 12_30_15-Checkmk Local site cmk - Services of Host Docker - Brave1126×273 31.4 KB

8

Then the only thing left to check is, if the host and container have the very same name.
If that is not the case, you need a rule “Hostname translation for piggybacked hosts” to map container name and host. Only if those two names align can the piggyback mechanism work.

9

Hello, I have installed the docker plugin on my host (name: kankra). This works fine, with the help of the dynamic host management I see allmy docker containers, including my CheckMK container (name: cmk). I have created a piggyback name mapping rule that maps kankra to cmk but the error in the main dashboard page still exists: “As soon as you add…”.
And therefore no graphs are shown.
What is wrong with this setup?
Best regards

Ralf

10

These are the docker services discovered on my docker host:

image
image1364×374 65.1 KB

The are the services dicovered within the dockerized checkmk host:
image
image1252×720 100 KB

This is my host name mapping rule:
image
image942×112 6.63 KB

Still no graphs within the main dashboard (and no services at all regarding the CheckMK site)

11

You need all servers that host Checkmk sites monitored, specifically the “Site statistics” service for every single site.

See also: "As soon as you add your Checkmk server to the monitoring, a graph showing the history of your host problems will appear here. Please refer to the Checkmk user guide for more details."

12

Hi Robin,
I solved the problem. I just added a host object with IP 127.0.0.1 to the monitoring. Now all the CheckMK specific services are shown within this host, in addition the default main dashboard is now populated with graphs. The drawback: There are some duplicated services like hard disks, which are now monitored within this host (reflecting the hard disks of the docker host), and the docker host itself, which is monitored by it’s real IP address. But this is just a question of disabling some or all of these services.
Thanks for your assistance.
Best regards

Ralf

13

This still sounds off, but as long as it works for you, I am glad you figured it out.