Avoid rbd unmap failure; use HostToContainer mountPropagation

The divingbell pods use a hostPath volume for the root filesystem.
Because this mount includes /var/lib/kubelet, the pod holds a reference
to every volume mounted by every pod on the same host.

The most visible case where this causes a problem is the termination of
a pod that uses a ceph-backed PVCs. When kubelet tries to unmap the rbd
device, it is unable to do so, manifesting in the kubelet logs as:
    rbd: unmap failed: (16) Device or resource busy

This change sets the mountPropagation to HostToContainer for the rootfs
volume, so that the divingbell pods will not prevent kubelet from
releasing these devices.

https://kubernetes.io/docs/concepts/storage/volumes/#mount-propagation

Change-Id: I6e91fb9b9d7cbe852c5e6dc8b7224d6085175590

divingbell/templates/daemonset-apparmor.yaml

@@ -58,6 +58,7 @@ spec:
           mountPath: /tmp
         - name: rootfs-{{ $daemonset }}
           mountPath: {{ .Values.conf.chroot_mnt_path }}
+          mountPropagation: HostToContainer
         - name: {{ $secretName }}
           mountPath: /tmp/{{ $daemonset }}.sh
           subPath: {{ $daemonset }}

divingbell/templates/daemonset-apt.yaml

@@ -58,6 +58,7 @@ spec:
           mountPath: /tmp
         - name: rootfs-{{ $daemonset }}
           mountPath: {{ .Values.conf.chroot_mnt_path }}
+          mountPropagation: HostToContainer
         - name: {{ $secretName }}
           mountPath: /tmp/{{ $daemonset }}.sh
           subPath: {{ $daemonset }}

divingbell/templates/daemonset-ethtool.yaml

@@ -58,6 +58,7 @@ spec:
           mountPath: /tmp
         - name: rootfs-{{ $daemonset }}
           mountPath: {{ .Values.conf.chroot_mnt_path }}
+          mountPropagation: HostToContainer
         - name: {{ $secretName }}
           mountPath: /tmp/{{ $daemonset }}.sh
           subPath: {{ $daemonset }}

divingbell/templates/daemonset-exec.yaml

@@ -58,6 +58,7 @@ spec:
           mountPath: /tmp
         - name: rootfs-{{ $daemonset }}
           mountPath: {{ .Values.conf.chroot_mnt_path }}
+          mountPropagation: HostToContainer
         - name: {{ $secretName }}
           mountPath: /tmp/{{ $daemonset }}.sh
           subPath: {{ $daemonset }}

divingbell/templates/daemonset-limits.yaml

@@ -58,6 +58,7 @@ spec:
           mountPath: /tmp
         - name: rootfs-{{ $daemonset }}
           mountPath: {{ .Values.conf.chroot_mnt_path }}
+          mountPropagation: HostToContainer
         - name: {{ $secretName }}
           mountPath: /tmp/{{ $daemonset }}.sh
           subPath: {{ $daemonset }}

divingbell/templates/daemonset-mounts.yaml

@@ -58,6 +58,7 @@ spec:
           mountPath: /tmp
         - name: rootfs-{{ $daemonset }}
           mountPath: {{ .Values.conf.chroot_mnt_path }}
+          mountPropagation: HostToContainer
         - name: {{ $secretName }}
           mountPath: /tmp/{{ $daemonset }}.sh
           subPath: {{ $daemonset }}

divingbell/templates/daemonset-perm.yaml

@@ -58,6 +58,7 @@ spec:
           mountPath: /tmp
         - name: rootfs-{{ $daemonset }}
           mountPath: {{ .Values.conf.chroot_mnt_path }}
+          mountPropagation: HostToContainer
         - name: {{ $secretName }}
           mountPath: /tmp/{{ $daemonset }}.sh
           subPath: {{ $daemonset }}

divingbell/templates/daemonset-sysctl.yaml

@@ -58,6 +58,7 @@ spec:
           mountPath: /tmp
         - name: rootfs-{{ $daemonset }}
           mountPath: {{ .Values.conf.chroot_mnt_path }}
+          mountPropagation: HostToContainer
         - name: {{ $secretName }}
           mountPath: /tmp/{{ $daemonset }}.sh
           subPath: {{ $daemonset }}

divingbell/templates/daemonset-uamlite.yaml

@@ -54,6 +54,7 @@ spec:
         volumeMounts:
         - name: rootfs-{{ $daemonset }}
           mountPath: {{ .Values.conf.chroot_mnt_path }}
+          mountPropagation: HostToContainer
         - name: {{ $secretName }}
           mountPath: /tmp/{{ $daemonset }}.sh
           subPath: {{ $daemonset }}