Copy kubectl from docker container

Nearly the last stage of source all components to containers.
Kubectl will be called from hyperkube image.

Remaining tasks:
 * Move kube_version variable to kubernetes/preinstall
 * Drop placeholder download.nothing requirement

roles/kubernetes/master/meta/main.yml

@@ -1,6 +1,6 @@
 ---
 dependencies:
-  - role: download
-    file: "{{ downloads.kubernetes_kubectl }}"
+  - role: download # For kube_version variable
+    file: "{{ downloads.nothing }}"
   - { role: etcd }
   - { role: kubernetes/node }

roles/kubernetes/master/tasks/main.yml

@@ -7,9 +7,10 @@
     dest: /etc/bash_completion.d/kubectl.sh
   when: ansible_os_family in ["Debian","RedHat"]
 
-- name: Copy kubectl binary
-  command: rsync -piu "{{ local_release_dir }}/kubernetes/bin/kubectl" "{{ bin_dir }}/kubectl"
+- name: Copy kubectl from hyperkube container
+  command: "/usr/bin/docker run --rm -v {{ bin_dir }}:/systembindir {{ hyperkube_image_repo }}:{{ hyperkube_image_tag }} /bin/cp /hyperkube /systembindir/kubectl"
   changed_when: false
+  register: kubectl_launcher
 
 - meta: flush_handlers