Kubernetes has a new resource type: `VolumeAttachments`. They provide
helpful information on where a volume is attached and to alert on
unexpected attachment status (for example, differences between
information scraped from node-exporter and kube-state-metrics).
The collector adds a bunch of new metrics. Each VolumeAttachment (ie.,
each CSI-attached volume) will have one of each, so we do not overly
pollute the metrics space. Most metrics are rather unsurprising.
- `kube_volumeattachment_status_attachment_metadata`: provides a
label-like export of the attachment metadata map. Generalizing the
label-conversion function slightly helps at providing this metric.
- `kube_volumeattachment_created`: as VolumeAttachments are
automatically created and we already suffered from duplicate
`VolumeAttachments`, this can be invaluable for debugging
misattachments.
- `kube_volumeattachment_spec_source_persistentvolume`: will only be
generated when the volume source is of `PersistentVolume` type. The
other type `inlineVolumeSpec` is still alpha-level and hard to map to
metrics.
No end-to-end test manifest was added, as `VolumeAttachment`s are
automatically generated when mounting volumes.
Signed-off-by: Jens Erat <email@jenserat.de>
main_test.go: Add model based test for sharding
In order to ensure a sharded system behaves equal to an unsharded
system, a model based test has been introduced. It scrapes an unsharded
setup and compares its output with the union of a sharded setup
therefore ensuring semantic equality.
Miles Bryant
Jens Erat
Nataly Sheinin
Frederic Branczyk
Tariq Ibrahim
Lili Cosic
Johann Bich