This plugin checks the health of a ceph cluster.
Usage ----
The plugin usage is given in the source code as the following:
Usage: check_ceph [-m|--mon] [-k|--key]
-m, --mon=ADDRESS[,ADDRESS,ADDRESS]
IP address(es) of ceph monitors
-k, --key=string
secret key to access the ceph cluster
-h, --help
Print detailed help screen
You can read about Nagios plugin development here:
In particular, you will likely be interested in learning about plugin output.