kubernetes: local storage PV can be created even if there are no such path

Is this a BUG REPORT or FEATURE REQUEST?:

/kind bug

What happened: I was using the local storage feature, but found that the PV can always be created even if the local path does not exist. This will cause my pod failed to start.

What you expected to happen: Can we make the PV creation failed?

How to reproduce it (as minimally and precisely as possible):

1. Two nodes in the cluster with local persistent volume enabled by feature gateway.

root@k8s001:~/cases/local-storage# kubectl get nodes
NAME      STATUS    AGE       VERSION
k8s001    Ready     29d       v1.8.0-alpha.1.685+950a09d982286a
k8s004    Ready     5h        v1.8.0-alpha.1.685+950a09d982286a

1. Create a PV with a non-exist local path, please note /mnt/disks/vol11 does not exist on any of the hosts in the cluster.

root@k8s001:~/cases/local-storage-fail# cat pv.yaml
apiVersion: v1
kind: PersistentVolume
metadata:
  name: example-local-pv
  annotations:
    "volume.alpha.kubernetes.io/node-affinity": '{
      "requiredDuringSchedulingIgnoredDuringExecution": {
        "nodeSelectorTerms": [
          { "matchExpressions": [
            { "key": "kubernetes.io/hostname",
              "operator": "In",
              "values": ["k8s001"]
            }
          ]}
         ]}
        }'
spec:
  capacity:
    storage: 1Gi
  accessModes:
  - ReadWriteOnce
  persistentVolumeReclaimPolicy: Delete
  storageClassName: local-storage
  local:
    path: /mnt/disks/vol11
root@k8s001:~/cases/local-storage-fail# kubectl create -f ./pv.yaml
persistentvolume "example-local-pv" created
root@k8s001:~/cases/local-storage-fail# kubectl get pv
NAME               CAPACITY   ACCESSMODES   RECLAIMPOLICY   STATUS      CLAIM     STORAGECLASS    REASON    AGE
example-local-pv   1Gi        RWO           Delete          Available             local-storage             1s

1. Create a PVC based on the PV

root@k8s001:~/cases/local-storage-fail# cat pvc.yaml
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: example-local-claim
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi
  storageClassName: local-storage
root@k8s001:~/cases/local-storage-fail# kubectl create -f ./pvc.yaml
persistentvolumeclaim "example-local-claim" created
root@k8s001:~/cases/local-storage-fail# kubectl get pvc
NAME                  STATUS    VOLUME             CAPACITY   ACCESSMODES   STORAGECLASS    AGE
example-local-claim   Bound     example-local-pv   1Gi        RWO           local-storage   3s

1. Create a pod with the pvc, pod creation failed due to the PV local path does not exist.

root@k8s001:~/cases/local-storage-fail# cat local.yaml
apiVersion: v1
kind: Pod
metadata:
  name: test-pd
spec:
  containers:
  - image: nginx:1.8.1
    name: test-container
    volumeMounts:
    - mountPath: /test-pd
      name: test-volume
  volumes:
  - name: test-volume
    persistentVolumeClaim:
          claimName: example-local-claim
root@k8s001:~/cases/local-storage-fail# kubectl create -f ./local.yaml
pod "test-pd" created
root@k8s001:~/cases/local-storage-fail# kubectl describe pods test-pd
Name:		test-pd
Namespace:	default
Node:		k8s001/192.168.56.11
Start Time:	Tue, 04 Jul 2017 17:09:03 +0800
Labels:		<none>
Annotations:	<none>
Status:		Pending
IP:
Containers:
  test-container:
    Container ID:
    Image:		nginx:1.8.1
    Image ID:
    Port:		<none>
    State:		Waiting
      Reason:		ContainerCreating
    Ready:		False
    Restart Count:	0
    Environment:	<none>
    Mounts:
      /test-pd from test-volume (rw)
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-8557l (ro)
Conditions:
  Type		Status
  Initialized 	True
  Ready 	False
  PodScheduled 	True
Volumes:
  test-volume:
    Type:	PersistentVolumeClaim (a reference to a PersistentVolumeClaim in the same namespace)
    ClaimName:	example-local-claim
    ReadOnly:	false
  default-token-8557l:
    Type:	Secret (a volume populated by a Secret)
    SecretName:	default-token-8557l
    Optional:	false
QoS Class:	BestEffort
Node-Selectors:	<none>
Tolerations:	<none>
Events:
  FirstSeen	LastSeen	Count	From			SubObjectPath	Type		Reason			Message
  ---------	--------	-----	----			-------------	--------	------			-------
  7s		7s		1	default-scheduler			Normal		Scheduled		Successfully assigned test-pd to k8s001
  7s		7s		1	kubelet, k8s001				Normal		SuccessfulMountVolume	MountVolume.SetUp succeeded for volume "default-token-8557l"
  7s		3s		4	kubelet, k8s001				Warning		FailedMount		MountVolume.SetUp failed for volume "example-local-pv" : mount failed: exit status 32
Mounting command: mount
Mounting arguments: /mnt/disks/vol11 /var/lib/kubelet/pods/6c9e7845-6098-11e7-a6a3-08002759511a/volumes/kubernetes.io~local-volume/example-local-pv  [bind]
Output: mount: special device /mnt/disks/vol11 does not exist

Anything else we need to know?:

Environment:

• Kubernetes version (use kubectl version):

root@k8s001:~/cases/local-storage# kubectl version
Client Version: version.Info{Major:"1", Minor:"8+", GitVersion:"v1.8.0-alpha.1.685+950a09d982286a", GitCommit:"950a09d982286a32a045f956d91680e0defd71dd", GitTreeState:"clean", BuildDate:"2017-07-02T11:23:13Z", GoVersion:"go1.8.1", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"8+", GitVersion:"v1.8.0-alpha.1.685+950a09d982286a", GitCommit:"950a09d982286a32a045f956d91680e0defd71dd", GitTreeState:"clean", BuildDate:"2017-07-02T11:23:13Z", GoVersion:"go1.8.1", Compiler:"gc", Platform:"linux/amd64"}

• Cloud provider or hardware configuration**:

root@k8s001:~/cases/local-storage# cat /etc/*release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=16.04
DISTRIB_CODENAME=xenial
DISTRIB_DESCRIPTION="Ubuntu 16.04 LTS"
NAME="Ubuntu"
VERSION="16.04 LTS (Xenial Xerus)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 16.04 LTS"
VERSION_ID="16.04"
HOME_URL="http://www.ubuntu.com/"
SUPPORT_URL="http://help.ubuntu.com/"
BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"
UBUNTU_CODENAME=xenial

• OS (e.g. from /etc/os-release):
• Kernel (e.g. uname -a):

root@k8s001:~/cases/local-storage# uname -a
Linux k8s001 4.4.0-83-generic #106-Ubuntu SMP Mon Jun 26 17:54:43 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

• Install tools: Manually.

• Others: