Fix for Helm on CoreOs using Docker

Helm (tiller) requires socat to run. CoreOS doesnt supply socat
with their OS (See coreos/bugs#1114) hence
we have to add it to the system during Kubernetes Deployment.
While there is a solution for this issue when running Kubernetes on CoreOS with Rkt
(Kubelet Wrapper https://coreos.com/kubernetes/docs/latest/kubelet-wrapper.html)
there is no when running Kubernetes on CoreOS with
Docker. For this reason we compiled a static socat binary we copy
to /opt/bin or another directory and add the PATH to the Kubelet Docker
Container to run Helm (tiller) on the Kubernetes Cluster.

roles/kubernetes-apps/helm/defaults/main.yml

@@ -0,0 +1,4 @@
+---
+socat_mode: 0700
+socat_owner: kube
+socat_dest: {{ bin_dir }}

roles/kubernetes-apps/helm/tasks/main.yml

@@ -1,3 +1,9 @@
 ---
-- debug:
-    msg: "No helm charts"
+- name: "Helm | Copy socat binary to {{ kube_binaries_dir }}"
+  copy:
+      src: "{{ role_path }}/files/socat"
+      dest: "{{ socat_dest }}"
+      owner: {{ socat_owner }}
+      mode:  {{ socat_mode }}
+  when: ansible_os_family == "Container Linux by CoreOS" and
+        kubelet_deployment_type == "docker"

roles/kubernetes-apps/meta/main.yml

@@ -17,3 +17,4 @@ dependencies:
   - role: kubernetes-apps/efk
     when: efk_enabled
     tags: [ apps, efk ]
+  - {role: kubernetes-apps/helm, tags: [apps, helm]}

roles/kubernetes/node/templates/kubelet-container.j2

@@ -23,6 +23,9 @@
   -v /var/lib/kubelet:/var/lib/kubelet:shared \
   -v /var/run:/var/run:rw \
   -v {{kube_config_dir}}:{{kube_config_dir}}:ro \
+ {% if ansible_os_family == "Container Linux by CoreOS" and kubelet_deployment_type == "docker" %}
+  -e PATH="$PATH:{{ socat_dest }}" \
+ {% endif %}
   {{ hyperkube_image_repo }}:{{ hyperkube_image_tag}} \
   ./hyperkube kubelet \
   "$@"