His PR cam during the middle of this development cycle, and it was easier to
burn it down and recreate it than try to patch it into an existing series and
re-test every assumption. This behavior will be re-introduced in subsequent
commits.
This PR contains Kubelet changes to enable attach/detach controller control.
* It introduces a new "enable-controller-attach-detach" kubelet flag to
enable control by controller. Default enabled.
* It removes all references "SafeToDetach" annoation from controller.
* It adds the new VolumesInUse field to the Node Status API object.
* It modifies the controller to use VolumesInUse instead of SafeToDetach
annotation to gate detachment.
* There is a bug in node-problem-detector that causes VolumesInUse to
get reset every 30 seconds. Issue https://github.com/kubernetes/node-problem-detector/issues/9
opened to fix that.
Automatic merge from submit-queue
Extend secrets volumes with path control
As per [1] this PR extends secrets mapped into volume with:
* key-to-path mapping the same way as is for configmap. E.g.
```
{
"apiVersion": "v1",
"kind": "Pod",
"metadata": {
"name": "mypod",
"namespace": "default"
},
"spec": {
"containers": [{
"name": "mypod",
"image": "redis",
"volumeMounts": [{
"name": "foo",
"mountPath": "/etc/foo",
"readOnly": true
}]
}],
"volumes": [{
"name": "foo",
"secret": {
"secretName": "mysecret",
"items": [{
"key": "username",
"path": "my-username"
}]
}
}]
}
}
```
Here the ``spec.volumes[0].secret.items`` added changing original target ``/etc/foo/username`` to ``/etc/foo/my-username``.
* secondly, refactoring ``pkg/volumes/secrets/secrets.go`` volume plugin to use ``AtomicWritter`` to project a secret into file.
[1] https://github.com/kubernetes/kubernetes/blob/master/docs/design/configmap.md#changes-to-secret
Automatic merge from submit-queue
Add subPath to mount a child dir or file of a volumeMount
Allow users to specify a subPath in Container.volumeMounts so they can use a single volume for many mounts instead of creating many volumes. For instance, a user can now use a single PersistentVolume to store the Mysql database and the document root of an Apache server of a LAMP stack pod by mapping them to different subPaths in this single volume.
Also solves https://github.com/kubernetes/kubernetes/issues/20466.
