This implements Bulk volume polling using ideas presented by
justin in https://github.com/kubernetes/kubernetes/pull/39564
But it changes the implementation to use an interface
and doesn't affect other implementations.
This PR is to fix the issue in converting aws volume id from mount
paths. Currently there are three aws volume id formats supported. The
following lists example of those three formats and their corresponding
global mount paths:
1. aws:///vol-123456
(/var/lib/kubelet/plugins/kubernetes.io/aws-ebs/mounts/aws/vol-123456)
2. aws://us-east-1/vol-123456
(/var/lib/kubelet/plugins/kubernetes.io/mounts/aws/us-est-1/vol-123455)
3. vol-123456
(/var/lib/kubelet/plugins/kubernetes.io/mounts/aws/us-est-1/vol-123455)
For the first two cases, we need to check the mount path and convert
them back to the original format.
When kubelet restarts, all the information about the volumes will be
gone from actual/desired states. When update node status with mounted
volumes, the volume list might be empty although there are still volumes
are mounted and in turn causing master to detach those volumes since
they are not in the mounted volumes list. This fix is to make sure only
update mounted volumes list after reconciler starts sync states process.
This sync state process will scan the existing volume directories and
reconstruct actual states if they are missing.
This PR also fixes the problem during orphaned pods' directories. In
case of the pod directory is unmounted but has not yet deleted (e.g.,
interrupted with kubelet restarts), clean up routine will delete the
directory so that the pod directoriy could be cleaned up (it is safe to
delete directory since it is no longer mounted)
The third issue this PR fixes is that during reconstruct volume in
actual state, mounter could not be nil since it is required for creating
container.VolumeMap. If it is nil, it might cause nil pointer exception
in kubelet.
Details are in proposal PR #33203
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.
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.
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.
- Add volume.MetricsProvider function to Volume interface.
- Add volume.MetricsDu for providing metrics via executing "du".
- Add volulme.MetricsNil for unsupported Volumes.
The GCE PD plugin uses safe_format_and_mount found on standard GCE images:
https://github.com/GoogleCloudPlatform/compute-image-packages/blob/master/google-startup-scripts/usr/share/google/safe_format_and_mount
On custom images where this is not available pods fail to format and
mount GCE PDs. This patch uses linux utilities in a similar way to the
safe_format_and_mount script to format and mount the GCE PD and AWS EBC
devices. That is first attempt a mount. If mount fails try to use file to
investigate the device. If 'file' fails to get any information about
the device and simply returns "data" then assume the device is not
formatted and format it and attempt to mount it again.
Signed-off-by: Sami Wagiaalla <swagiaal@redhat.com>
IsLikelyNotMountPoint determines if a directory is not a mountpoint.
It is fast but not necessarily ALWAYS correct. If the path is in fact
a bind mount from one part of a mount to another it will not be detected.
mkdir /tmp/a /tmp/b; mount --bin /tmp/a /tmp/b; IsLikelyNotMountPoint("/tmp/b")
will return true. When in fact /tmp/b is a mount point. So this patch
renames the function and switches it from a positive to a negative (I
could think of a good positive name). This should make future users of
this function aware that it isn't quite perfect, but probably good
enough.
Matthew Wong