Bug 1451007

https://github.com/openshift/origin/pull/14193

Tested on openshift v3.5.5.23

Pod failed to start given the subPath is not a directory, it failed with mount error:
```
Failed to start container with docker id a906aa02f938 with error: Error response from daemon: {"message":"invalid header field value \"oci runtime error: container_linux.go:247: starting container process caused \\\"process_linux.go:359: container init caused \\\\\\\"rootfs_linux.go:54: mounting \\\\\\\\\\\\\\\"/var/lib/origin/openshift.local.volumes/pods/3a5cc9d1-49bb-11e7-a437-fa163eed6cea/volumes/kubernetes.io~nfs/pvol/file\\\\\\\\\\\\\\\" to rootfs \\\\\\\\\\\\\\\"/var/lib/docker/devicemapper/mnt/c39df92ec2572d6c793b2e8402064b45fce1b4e5ae1c0cd5648cfa53219ff874/rootfs\\\\\\\\\\\\\\\" at \\\\\\\\\\\\\\\"/var/lib/docker/devicemapper/mnt/c39df92ec2572d6c793b2e8402064b45fce1b4e5ae1c0cd5648cfa53219ff874/rootfs/opt\\\\\\\\\\\\\\\" caused \\\\\\\\\\\\\\\"not a directory\\\\\\\\\\\\\\\"\\\\\\\"\\\"\\n\""}
```

Changing to assigned since we expect the it to be in Running state.

1. Create Pod
{
    "apiVersion": "v1",
    "kind": "Pod",
    "metadata": {
        "name": "mypod1",
        "labels": {
            "name": "frontendhttp"
        }
    },
    "spec": {
        "containers": [{
            "name": "myfrontend",
            "image": "jhou/hello-openshift",
            "imagePullPolicy": "IfNotPresent",
            "ports": [{
                "containerPort": 80,
                "name": "http-server"
            }],
            "volumeMounts": [{
                "mountPath": "/opt",
                "subPath": "file",
                "name": "pvol"
            }]
        }],
        "volumes": [{
            "name": "pvol",
            "nfs": {
                "server": "xxx",
                "path": "/nfs",
                "readOnly": false
            }
        }]
    }
}
2. oc get pods
NAME      READY     STATUS             RESTARTS   AGE
mypod1    0/1       CrashLoopBackOff   6          9m

3. oc describe pod mypod1
  11m		11m		1	{default-scheduler }									Normal		Scheduled	Successfully assigned mypod1 to host-8-175-116.host.centralci.eng.rdu2.redhat.com
  11m		11m		1	{kubelet host-8-175-116.host.centralci.eng.rdu2.redhat.com}	spec.containers{myfrontend}	Normal		Created		Created container with docker id a2133de5a048; Security:[seccomp=unconfined]
  11m		11m		1	{kubelet host-8-175-116.host.centralci.eng.rdu2.redhat.com}	spec.containers{myfrontend}	Warning		Failed		Failed to start container with docker id a2133de5a048 with error: Error response from daemon: {"message":"invalid header field value \"oci runtime error: container_linux.go:247: starting container process caused \\\"process_linux.go:359: container init caused \\\\\\\"rootfs_linux.go:54: mounting \\\\\\\\\\\\\\\"/var/lib/origin/openshift.local.volumes/pods/3a5cc9d1-49bb-11e7-a437-fa163eed6cea/volumes/kubernetes.io~nfs/pvol/file\\\\\\\\\\\\\\\" to rootfs \\\\\\\\\\\\\\\"/var/lib/docker/devicemapper/mnt/9c59a37dc240dbbe6012ad02018a54ea376167b455126384b99106776d2cca1b/rootfs\\\\\\\\\\\\\\\" at \\\\\\\\\\\\\\\"/var/lib/docker/devicemapper/mnt/9c59a37dc240dbbe6012ad02018a54ea376167b455126384b99106776d2cca1b/rootfs/opt\\\\\\\\\\\\\\\" caused \\\\\\\\\\\\\\\"not a directory\\\\\\\\\\\\\\\"\\\\\\\"\\\"\\n\""}
  11m		11m		1	{kubelet host-8-175-116.host.centralci.eng.rdu2.redhat.com}				Warning		FailedSync	Error syncing pod, skipping: failed to "StartContainer" for "myfrontend" with RunContainerError: "runContainer: Error response from daemon: {\"message\":\"invalid header field value \\\"oci runtime error: container_linux.go:247: starting container process caused \\\\\\\"process_linux.go:359: container init caused \\\\\\\\\\\\\\\"rootfs_linux.go:54: mounting \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\"/var/lib/origin/openshift.local.volumes/pods/3a5cc9d1-49bb-11e7-a437-fa163eed6cea/volumes/kubernetes.io~nfs/pvol/file\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\" to rootfs \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\"/var/lib/docker/devicemapper/mnt/9c59a37dc240dbbe6012ad02018a54ea376167b455126384b99106776d2cca1b/rootfs\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\" at \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\"/var/lib/docker/devicemapper/mnt/9c59a37dc240dbbe6012ad02018a54ea376167b455126384b99106776d2cca1b/rootfs/opt\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\" caused \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\"not a directory\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\"\\\\\\\\\\\\\\\"\\\\\\\"\\\\n\\\"\"}"

Jianwei, please try editing the pod spec from "mountPath": "/opt" to "mountPath": "/opt/file"? That error occurs because "/opt" already exists in the container, and 

                "mountPath": "/opt",
                "subPath": "file",

means "mount /nfs/file /opt", not "mount /nfs/file /opt/file" as one might expect.

(In reply to Matthew Wong from comment #5)
> Jianwei, please try editing the pod spec from "mountPath": "/opt" to
> "mountPath": "/opt/file"? That error occurs because "/opt" already exists in
> the container, and 
> 
>                 "mountPath": "/opt",
>                 "subPath": "file",
> 
> means "mount /nfs/file /opt", not "mount /nfs/file /opt/file" as one might
> expect.

Sorry for the incorrect mountPath. I've verified it following your instruction and now it works. Thank you.

This bug is verified according to comment 6

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2017:1425