checkmk-ceph-rook-rados

Enable Checkmk ceph plugin to monitor Kubernetes based Rook Ceph installation

The Problem

If a Kubernetes Rook Ceph installation should be monitored via the great Checkmk Ceph Plugin the plugin won't work if installed locally on the host. This happens because it depends on the module rados which works only with a local installation.

The Solution

Putting the file rados.py into the same directory /usr/lib/check_mk_agent/plugins/58 as the ceph plugin on the host allows the plugin to import the module rados as before:

~# ls -l /usr/lib/check_mk_agent/plugins/58
total 12
-rwxr-xr-x 1 root root 4255 Dec 20 15:09 ceph
-rw-r--r-- 1 root root 2784 Dec 21 14:27 rados.py

This local rados.py uses

kubectl -n rook-ceph exec -it deploy/rook-ceph-tools -- ceph

to execute Ceph commands. Thus it can supply Checkmk with the expected Ceph output and the Rook Ceph instance is monitored.

Some Customization

As of now one will need to customize the file rados.py to match the real monitor names it is used on. Rook Ceph names all monitors alphabetically, starting with 'a'. To get the real hostnames in Checkmk some customization will be required:

• the simplest case might be to change CEPH_HOSTNAME_TEMPLATE
• more sophisticated needs can be adjusted in lines 46-53