download only required kubernetes binaries

roles/download/defaults/main.yml

 ---
-etcd_download_url: https://github.com/coreos/etcd/releases/download
-flannel_download_url: https://github.com/coreos/flannel/releases/download
-kube_download_url: https://github.com/GoogleCloudPlatform/kubernetes/releases/download
-calico_download_url: https://github.com/Metaswitch/calico-docker/releases/download
-
 etcd_version: v2.2.2
 flannel_version: 0.5.5
 
 kube_version: v1.1.2
-kube_sha1: 69d110d371752c6492d2f8695aa7a47be5b6ed4e
+kubectl_checksum: "e0585c6e63f796d87b34cd1f16554892a49421b98a2862a896b2b7ebf1439ace"
+kubelet_checksum: "6c029d34888e1ec4b9ab4b500b0712388984340488c5f3c19e2c759d1003cbff"
+
+calico_version: v0.12.0
+
+etcd_download_url: "https://github.com/coreos/etcd/releases/download"
+flannel_download_url: "https://github.com/coreos/flannel/releases/download"
+kube_download_url: "https://storage.googleapis.com/kubernetes-release/release/{{ kube_version }}/bin/linux/amd64"
+calico_download_url: "https://github.com/Metaswitch/calico-docker/releases/download"
 
-calico_version: v0.11.0

roles/download/tasks/kubernetes.yml

 ---
-- name: Create kubernetes release directory
+- name: Create kubernetes binary directory
   local_action: file
-     path={{ local_release_dir }}/kubernetes
+     path="{{ local_release_dir }}/kubernetes/bin"
      state=directory
+     recurse=yes
 
-- name: Check if kubernetes release archive has been downloaded
-  local_action: stat
-     path={{ local_release_dir }}/kubernetes/kubernetes.tar.gz
-  register: k_tar
-
-# issues with get_url module and redirects, to be tested again in the near future
-- name: Download kubernetes
-  local_action: shell
-    curl -o {{ local_release_dir }}/kubernetes/kubernetes.tar.gz -Ls {{ kube_download_url }}/{{ kube_version }}/kubernetes.tar.gz
-  when: not k_tar.stat.exists or k_tar.stat.checksum != "{{ kube_sha1 }}"
-  register: dl_kube
-
-- name: Compare kubernetes archive checksum
-  local_action: stat
-     path={{ local_release_dir }}/kubernetes/kubernetes.tar.gz
-  register: k_tar
-  failed_when: k_tar.stat.checksum != "{{ kube_sha1 }}"
-  when: dl_kube|changed
-
-- name: Extract kubernetes archive
-  local_action: unarchive
-     src={{ local_release_dir }}/kubernetes/kubernetes.tar.gz
-     dest={{ local_release_dir }}/kubernetes copy=no
-  when: dl_kube|changed
-
-- name: Extract kubernetes binaries archive
-  local_action: unarchive
-     src={{ local_release_dir }}/kubernetes/kubernetes/server/kubernetes-server-linux-amd64.tar.gz
-     dest={{ local_release_dir }}/kubernetes copy=no
-  when: dl_kube|changed
-
-- name: Pick up only kubernetes binaries
-  local_action: synchronize
-     src={{ local_release_dir }}/kubernetes/kubernetes/server/bin
-     dest={{ local_release_dir }}/kubernetes
-  when: dl_kube|changed
-
-- name: Delete unused kubernetes files
-  local_action: file
-     path={{ local_release_dir }}/kubernetes/kubernetes state=absent
-  when: dl_kube|changed
+- name: Download kubelet and kubectl
+  local_action: get_url
+    url="{{ kube_download_url }}/{{ item.name }}"
+    dest="{{ local_release_dir }}/kubernetes/bin"
+    sha256sum="{{ item.checksum }}"
+  with_items:
+    - name: kubelet
+      checksum: "{{ kubelet_checksum }}"
+    - name: kubectl
+      checksum: "{{ kubectl_checksum }}"