Write a bash or python nagios plugin that checks inode usage of multiple docker containers, and displays the name of the container, or containers that exceed warning or critical thresholds

We make use of 2 commands, redirecting output to temp files I imagine. The commands are:

1 - df -i | grep devicemapper

and

2 - docker ps --format "{{.ID}}" | xargs docker inspect -f "{{.GraphDriver.Data.DeviceName}} {{.Name}}"

The output of each of these commands overlaps with the other, and so I want 3 possible outcomes typical for nagios:

if [[ "$warning_alert" -eq 1 ]]; then
echo "WARNING: Container $alerting_container on host `hostname` exceeds the warning level of inode usage percentage, which is $warn%"
exit $WARNING

elif [[ "$critical_alert" -eq 1 ]]; then
echo "CRITICAL: Container $alerting_container on host `hostname` exceeds the critical level of inode usage percentage, which is $crit%"
exit $CRITICAL

else
echo "OK: All docker container devicemapper filesystems on host `hostname` are within acceptable limits of inode usage percentage, which is under $warn%"
exit $OK
fi

I've made a start on this [uploaded here] but cannot get it to work exactly - if you can debug that might make the job shorter, but if not write a new script why not.