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kubernetespersistent-volumes

Kubernetes - is a container's volumeMounts.mountPath relative to the PersistentVolume's hostPath?

Let's say I create a PersistentVolume of type hostPath:

kind: PersistentVolume
apiVersion: v1
metadata:
  name: mypv
spec:
  storageClassName: normal
  capacity:
    storage: 10Gi
  accessModes:
    - ReadWriteMany
  hostPath:
    path: /etc/foo  # Path on the host machine

and I create the corresponding PersistentVolumeClaim, and use it in a Pod:

apiVersion: v1
kind: Pod
metadata:
  labels:
    run: busybox
  name: busybox
spec:
  containers:
  - image: busybox
    name: busybox
    volumeMounts:
    - name: myvolume
      mountPath: /var/log # is this relative to the hostPath of the PV?
  restartPolicy: Never
  volumes:
  - name: myvolume
    persistentVolumeClaim
      claimName: mypvc
status: {}

Is it expected that the result would be {hostPath}/{mountPath} (e.g. /etc/foo/var/log), or would I have to specifically define mountPath: /etc/foo/var/log to get it there?

Solution

  • The mountPath is the mountpoint inside the container. It is an absolute path starting at the container's filesystem root. If mountPath is /var/log, then the volume will be mounted on /var/log inside the container.

    If you have a hostPath volume pointing at /etc/foo on the host and mountPath pointing at /var/log in the container, then you will find the contents of /etc/foo available inside /var/log inside the container.

    For more details, see the documentation.