Monitoring results of curl page for thresholds

I can do a curl on a page like this:

curl --user test:test01 -X ‘GET’
-k -H ‘accept: application/json’

and get some fields and values returned so I know how much space is used on an nfs share. But how do I get something like that in Icinga?

I looked at check_http - this will give me an output on the page but then how to parse out the info I need and then to make it into a service check, example 40GB extracted from the field is checked against 24W/40C thresholds.

I understand this is perhaps a lazy thing to ask but just before I set off and make something way over elaborate is there any easy way to do this with say a plugin I have missed.

Note: do not have access to python 3.

I would use some kind of language to write a little program, that can use the info and set the message and exit code - in effect write a check plugin.

Also possible is pushing via Icinga2 API as passive check. icinga2-api process-check-result

If you can get the info as CSV by stating accept: application/csv you could use monitoring-plugins/check-plugins/csv-values at main · Linuxfabrik/monitoring-plugins · GitHub.

If you want the check written for you, you could ask the Linuxfabrik or others for a quote.