Gluster provisioner is interested in pvc.Namespace and I don't want to add
at as a new field in VolumeOptions - it would contain almost whole PVC.
Let's pass direct reference to PVC instead and let the provisioner to pick
information it is interested in.
We had another bug where we confused the hostname with the NodeName.
To avoid this happening again, and to make the code more
self-documenting, we use types.NodeName (a typedef alias for string)
whenever we are referring to the Node.Name.
A tedious but mechanical commit therefore, to change all uses of the
node name to use types.NodeName
Also clean up some of the (many) places where the NodeName is referred
to as a hostname (not true on AWS), or an instanceID (not true on GCE),
etc.
Currently kubelet volume management works on the concept of desired
and actual world of states. The volume manager periodically compares the
two worlds and perform volume mount/unmount and/or attach/detach
operations. When kubelet restarts, the cache of those two worlds are
gone. Although desired world can be recovered through apiserver, actual
world can not be recovered which may cause some volumes cannot be cleaned
up if their information is deleted by apiserver. This change adds the
reconstruction of the actual world by reading the pod directories from
disk. The reconstructed volume information is added to both desired
world and actual world if it cannot be found in either world. The rest
logic would be as same as before, desired world populator may clean up
the volume entry if it is no longer in apiserver, and then volume
manager should invoke unmount to clean it up.
Modify attach/detach controller to keep track of volumes to report
attached in Node VolumeToAttach status.
Modify kubelet volume manager to wait for volume to show up in Node
VolumeToAttach status.
Implement exponential backoff for errors in volume manager and attach
detach controller
This commit adds a new volume manager in kubelet that synchronizes
volume mount/unmount (and attach/detach, if attach/detach controller
is not enabled).
This eliminates the race conditions between the pod creation loop
and the orphaned volumes loops. It also removes the unmount/detach
from the `syncPod()` path so volume clean up never blocks the
`syncPod` loop.
This is a first-aid bandage to let admission controller ignore persistent
volumes that are being provisioned right now and thus may not exist in
external cloud infrastructure yet.
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.
Add a mutex to guard SetUpAt() and TearDownAt() calls - they should not
run in parallel. There is a race in these calls when there are two pods
using the same volume, one of them is dying and the other one starting.
TearDownAt() checks that a volume is not needed by any pods and detaches the
volume. It does so by counting how many times is the volume mounted
(GetMountRefs() call below).
When SetUpAt() of the starting pod already attached the volume and did not mount
it yet, TearDownAt() of the dying pod will detach it - GetMountRefs() does not
count with this volume.
These two threads run in parallel:
dying pod.TearDownAt("myVolume") starting pod.SetUpAt("myVolume")
| |
| AttachDisk("myVolume")
refs, err := mount.GetMountRefs() |
Unmount("myDir") |
if refs == 1 { |
| | Mount("myVolume", "myDir")
| | |
| DetachDisk("myVolume") |
| start containers - OOPS! The volume is detached!
|
finish the pod cleanup
Also, add some logs to cinder plugin for easier debugging in the future, add
a test and update the fake mounter to know about bind mounts.
This synchronizes Cinder with AWS EBS code, where we already tag volumes with
claim.Namespace and claim.Name (and pv.Name, as suggested in separate PR).
- Add volume.MetricsProvider function to Volume interface.
- Add volume.MetricsDu for providing metrics via executing "du".
- Add volulme.MetricsNil for unsupported Volumes.
Jan Safranek