metricbeat filesystem metrics not being output to prometheus

[KlavsKlavsen]

In my metricbeat console output I have this:

  "system": {
    "filesystem": {
      "type": "fuse.glusterfs",
      "device_name": "10.154.131.242:vol_f19380703ea925da14813fcfa05fa331",
      "available": 10524708864,
      "mount_point": "/mnt",
      "free_files": 5225819,
      "used": {
        "pct": 0.0189,
        "bytes": 202223616
      },
      "total": 10726932480,
      "files": 5242880,
      "free": 10524708864
    }
  },

But in metric output from beat-exporter I only have:
metricbeat_metricbeat_system_filesystem system.filesystem
metricbeat_metricbeat_system_filesystem counter

and event failures and success.. Nothing about the above stats - which is what I actually need :(

[KlavsKlavsen]

from a quick glance at the GO code (I've never written GO before :) - it seems it would need to add a filesystem struct like this memstat one: https://github.com/trustpilot/beat-exporter/blob/master/collector/beat.go#L33
And then adding sections for parsing each counter like that : https://github.com/trustpilot/beat-exporter/blob/master/collector/beat.go#L109
But only for metricbeat with system collector enabled ofcourse.. (or does it just ignore if its not there)
?

[KlavsKlavsen]

or perhaps more like this: https://github.com/trustpilot/beat-exporter/blob/master/collector/beat.go#L89 - setting labels for instance and device_name and counter name simply being the used.pct and used.bytes total, files, free and free_files (which I assume is actually inodes free :)

[KlavsKlavsen]

Am I on the right track here? then I can try it out :)

[KlavsKlavsen]

and it should be a gauge - not a counter I think

[KlavsKlavsen]

I just investigated a bit, and can see that filesystem stats is not exposed via http interface - and it seems from discussion on elastic forum that they never will be (they're not interested in metricbeat being usable for anything other than their stack :(