We should use clone of recycler pod template instead of reusing the same
one for two or more recyclers running in parallel.
Also add some logs to relevant places to spot the error easily next time.
This allows users to diagnose what's wrong with recycler. Recycler pods are
started automatically with a cryptic name and they are deleted immediately
when they finish.
kubectl describe pods will show:
FirstSeen LastSeen Count From SubobjectPath Type Reason Message
--------- -------- ----- ---- ------------- -------- ------ -------
59m 59m 1 {persistentvolume-controller } Warning RecyclerPod Recycler pod: Unable to mount volumes for pod "recycler-for-nfs_default(5421800e-347b-11e6-a79b-3c970e965218)": timeout expired waiting for volumes to attach/mount for pod "recycler-for-nfs"/"default". list of unattached/unmounted volumes=[vol]
53m 53m 1 {persistentvolume-controller } Warning RecyclerPod Recycler pod: Unable to mount volumes for pod "recycler-for-nfs_default(3c9809e5-347c-11e6-a79b-3c970e965218)": timeout expired waiting for volumes to attach/mount for pod "recycler-for-nfs"/"default". list of unattached/unmounted volumes=[vol]
46m 46m 1 {persistentvolume-controller } Warning RecyclerPod Recycler pod: Unable to mount volumes for pod "recycler-for-nfs_default(250dd2a2-347d-11e6-a79b-3c970e965218)": timeout expired waiting for volumes to attach/mount for pod "recycler-for-nfs"/"default". list of unattached/unmounted volumes=[vol]
40m 40m 1 {persistentvolume-controller } Warning RecyclerPod Recycler pod: Unable to mount volumes for pod "recycler-for-nfs_default(0d84ea33-347e-11e6-a79b-3c970e965218)": timeout expired waiting for volumes to attach/mount for pod "recycler-for-nfs"/"default". list of unattached/unmounted volumes=[vol]
33m 33m 1 {persistentvolume-controller } Warning RecyclerPod Recycler pod: Unable to mount volumes for pod "recycler-for-nfs_default(f5fb63bf-347e-11e6-a79b-3c970e965218)": timeout expired waiting for volumes to attach/mount for pod "recycler-for-nfs"/"default". list of unattached/unmounted volumes=[vol]
27m 27m 1 {persistentvolume-controller } Warning RecyclerPod Recycler pod: Unable to mount volumes for pod "recycler-for-nfs_default(de7128fd-347f-11e6-a79b-3c970e965218)": timeout expired waiting for volumes to attach/mount for pod "recycler-for-nfs"/"default". list of unattached/unmounted volumes=[vol]
1h 3m 75 {persistentvolume-controller } Normal RecyclerPod Recycler pod: Successfully assigned recycler-for-nfs to 127.0.0.1
1h 3m 76 {persistentvolume-controller } Normal RecyclerPod Recycler pod: Pod was active on the node longer than specified deadline
1h 1m 12 {persistentvolume-controller } Warning RecyclerPod Recycler pod: Error syncing pod, skipping: timeout expired waiting for volumes to attach/mount for pod "recycler-for-nfs"/"default". list of unattached/unmounted volumes=[vol]
20m 1m 4 {persistentvolume-controller } Warning RecyclerPod (events with common reason combined)
These steps were necessary:
- added event watcher to volume.RecycleVolumeByWatchingPodUntilCompletion
- pass all these events through volume plugins to volume controller
- rework volume.RecycleVolumeByWatchingPodUntilCompletion unit tests to a table
(too much copy-paste)
- fix all unit tests along the way
Automatic merge from submit-queue
Verify volume.GetPath() never returns ""
Add a new helper method volume.GetPath(Mounter) instead of calling
the GetPath() of the Mounter directly. Check if GetPath() is returning
a "" and convert that into an error.
Fixes#23163
Add a new helper method volume.GetPath(Mounter) instead of calling
the GetPath() of the Mounter directly. Check if GetPath() is returning
a "" and convert that into an error. At this point, we only have
information about the type of the Mounter, so let's log that if
there is a problem
Fixes#23163
Lots of comments describing the heuristics, how it fits together and the
limitations.
In particular, we can't guarantee correct volume placement if the set of
zones is changing between allocating volumes.
Long term we plan on integrating this into the scheduler, but in the
short term we use the volume name to place it onto a zone.
We hash the volume name so we don't bias to the first few zones.
If the volume name "looks like" a PetSet volume name (ending with
-<number>) then we use the number as an offset. In that case we hash
the base name.
Fixes#27256
Recycling is a long duration process and when the recycler controller is
restarted in the meantime, it should not start a new recycler pod if there is
one already running.
This means that the recycler pod must have deterministic name based on name
of the recycled PV, we then get name conflicts when creating the pod.
Two things need to be changed:
- recycler controller and recycler plugins must pass the PV.Name to place,
where the pod is created.
- create recycler pod with deterministic name and check "already exists" error.
When at it, remove useless 'resourceVersion' argument and make log messages
starting with lowercase.
Volume names have now format <cluster-name>-dynamic-<pv-name>.
pv-name is guaranteed to be unique in Kubernetes cluster, adding
<cluster-name> ensures we don't conflict with any running cluster
in the cloud project (kube-controller-manager --cluster-name=XXX).
'kubernetes' is the default cluster name.
Clayton Coleman