Files in pkg/util/mount that contain significant code implementation for
subpaths are moved to a new package at pkg/volume/util/subpath. This
move is done in order to preserve git history.
If a iSCSI target is down while a volume is attached, reading from
/sys/class/iscsi_host/host415/device/session383/connection383:0/iscsi_connection/connection383:0/address
fails with an error. Kubelet should assume that such target is not
available / logged in and try to relogin. Eventually, if such error
persists, it should continue mounting the volume if the other
paths are healthy instead of failing whole WaitForAttach().
The messages for container lifecycle events are subtly inconsistent
and should be unified.
First, the field format for containers is hard to parse for a human,
so include the container name directly in the message for create
and start, and for kill remove the container runtime prefix.
Second, the pulling image event has inconsistent capitalization, fix
that to be sentence without punctuation.
Third, the kill container event was unnecessarily wordy and inconsistent
with the create and start events. Make the following changes:
* Use 'Stopping' instead of 'Killing' since kill is usually reserved for
when we decide to hard stop a container
* Send the event before we dispatch the prestop hook, since this is an
"in-progress" style event vs a "already completed" type event
* Remove the 'cri-o://' / 'docker://' prefix by printing the container
name instead of id (we already do that replacement at the lower level
to prevent high cardinality events)
* Use 'message' instead of 'reason' as the argument name since this is a
string for humans field, not a string for machines field
* Remove the hash values on the container spec changed event because no
human will ever be able to do anything with the hash value
* Use 'Stopping container %s(, explanation)?' form without periods to
follow event conventions
The end result is a more pleasant message for humans:
```
35m Normal Created Pod Created container
35m Normal Started Pod Started container
10m Normal Killing Pod Killing container cri-o://installer:Need to kill Pod
10m Normal Pulling Pod pulling image "registry.svc.ci.openshift.org/openshift/origin-v4.0-2019-02-10-172026@sha256:3da5303d4384d24691721c1cf2333584ba60e8f82c9e782f593623ce8f83ddc5"
```
becomes
```
35m Normal Created Pod Created container installer
35m Normal Started Pod Started container installer
10m Normal Killing Pod Stopping container installer
10m Normal Pulling Pod Pulling image "registry.svc.ci.openshift.org/openshift/origin-v4.0-2019-02-10-172026@sha256:3da5303d4384d24691721c1cf2333584ba60e8f82c9e782f593623ce8f83ddc5"
```
