The Nagios Plugins for Linux are intended to be run by NRPE, the Nagios Remote Plugin Executor, that "allows you to remotely execute Nagios plugins on other Linux/Unix machines. This allows you to monitor remote machine metrics (disk usage, CPU load, etc.)."

Plugin name : check_memory which will checks the memory usage in a linux machine.

You can create your own plugin or you can download from Nagios: https://exchange.nagios.org/components/com_mtree/attachment.php?link_id=3407&cf_id=24

Once download keep the script in the tmp directory and then run the ansible playbook and you can configure the memory service in Nagios:

ansible-playbook -i hosts check_mem.yml

Example:

For memory Check:

./check_memory.sh -u -w 80 -c 95 w: warning c : critical u : used

For read only file system check :

/check_ro_fs.sh -p / OK: File system / appears to be ok

p : path