kubernetes: mounting volume from within init container

I'm trying to make use of init container to prepare some files before the main container starts up. In the init container I'd like to mount a hostPath volume so that I can share prepare some file for the main container.

My cluster is using pre 1.6 version of kubernetes so I'm using the meta.annotation syntax:

pod.beta.kubernetes.io/init-containers: '[
    {
        "name": "init-myservice",
        "image": "busybox",
        "command": ["sh", "-c", "mkdir /tmp/jack/ && touch cd /tmp/jack && touch a b c"],
        "volumeMounts": [{
          "mountPath": "/tmp/jack",
          "name": "confdir"
        }]
    }
]'

But it doesn't seem to work. The addition of volumeMounts cause the container init-myserver go into CrashLoop. Without it the pod gets created successfully but it doesn't achieve what I want.

Is it not possible in <1.5 to mount volume in init container? What about 1.6+?