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.
The key to path mapping allows pod to specify different name (thus location) of each secret.
At the same time refactor the volume plugin to use AtomicWritter to project secrets to files in a volume.
Update e2e Secrets test, the secret file permission has changed from 0444 to 0644
Remove TestPluginIdempotent as the AtomicWritter is responsible for secret creation
* Metrics will not be expose until they are hooked up to a handler
* Metrics are not cached and expose a dos vector, this must be fixed before release or the stats should not be exposed through an api endpoint
- Add volume.MetricsProvider function to Volume interface.
- Add volume.MetricsDu for providing metrics via executing "du".
- Add volulme.MetricsNil for unsupported Volumes.
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.
