This PR is to modify the containerized mounter script to use chroot
instead of rkt fly. This will avoid the problem of possible large number
of mounts caused by rkt containers if they are not cleaned up.
This is a fix on top #38124. In this fix, we move the logic to filter
out shared mount references into operation_executor's UnmountDevice
function to avoid this part is being used by other types volumes such as
rdb, azure etc. This filter function should be only needed during
unmount device for GCI image.
this is a workaround for the unmount device issue caused by gci mounter. In GCI cluster, if gci mounter is used for mounting, the container started by mounter script will cause additional mounts created in the container. Since these mounts are irrelavant to the original mounts, they should be not considered when checking the mount references. By comparing the mount path prefix, those additional mounts can be filtered out.
Plan to work on better approach to solve this issue.
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.
In order to be able to use new mounter library, this PR adds the
mounterPath flag to kubelet which passes the flag to the mount
interface. If flag is empty, mount uses default mount path.
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.
fix https://github.com/kubernetes/kubernetes/issues/24717
If kubelet root-dir is a symlink, the pod's cinder volume dir can't be
umounted even after pod is deleted.
This patch reads target path of symlink before comparing with entries in
proc mounts.
Kubelet was not able to mount volumes when running inside a container and
using nsenter mounter,
NsenterMounter.IsLikelyNotMountPoint() should return ErrNotExist when the
checked directory does not exists as the regular mounted does this and
some volume plugins depend on this behavior.
The `file` command used here to check whether a device is formatted is not
available for CoreOS. The effect is that the mounter tries to mount an
unformatted volume which fails. This makes it quite tedious to use persistent
volumes in CoreOS.
This patch replaces the `file` command with `lsblk` which is available in
CoreOS. I checked that it's also available on RHEL, Debian, Ubuntu and SLES.
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.
Jing Xu