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.
This fixes an issue where it was impossible to specify a collector that
was available but not selected by default.
Instead of checking whether chosen collectors are valid at flag parse
time, this moves the check into the builder, where we can reference it
against the availableStores in the builder. As a bonus, the error
message also prints out a list of available collectors:
```
kube-state-metrics --collectors non-existent-collector
I0618 15:23:34.517532 50719 main.go:88] Using collectors non-existent-collector
F0618 15:23:34.519132 50719 main.go:90] Error: collector non-existent-collector does not exist. Available collectors: persistentvolumeclaims,configmaps,limitranges,nodes,namespaces,persistentvolumes,pods,replicasets,services,cronjobs,deployments,ingresses,horizontalpodautoscalers,jobs,poddisruptionbudgets,secrets,certificatesigningrequests,daemonsets,endpoints,storageclasses,replicationcontrollers,resourcequotas,statefulsets
```
Instead of iterating a map of enabled collectors, iterate a sorted
slice to achieve determinism across scrapes.
Having a consistent order in the metrics output enables Proemetheus to
apply optimizations during metric parsing and ingestion.
Dependent on the environment users might or might not want to encode the
responses of kube-state-metrics via gzip independent of the
`Accept-Header` that the client (Prometheus) sends.
Manuel Rüger
Mikulas (Mike) Dite
Lili Cosic
Joel Whittaker-Smith
vikkyomkar
Alexander Carpenter
yeya24
Thibault Le Reste
Kubernetes Prow Robot
asidorovj
Tariq Ibrahim
Miles Bryant
Jens Erat
Ben Wells
Nataly Sheinin
Frederic Branczyk
xieyanker
reetasingh
Haoran Wang
tariqibrahim
Raphael Deem
Max Leonard Inden
Greg Lyons
Andy Xie