Add support for RKE kubernetes implementation

Added a new playbook rke.yml and role rke which uses rancher RKE:
https://github.com/rancher/rke

It's an implementation of the kubernetes from rancher.com folks
and it is an alternative to the official kubernetes tool: kubeadm.

NOTE: Rancher has a notion of a 'control plane' which cannot run with
etcd on all nodes in a multi-node setup. Control-plane node is the
first kubernetes node from the inventory (as of now).

Change-Id: I0bf669442a5183efa20d44fb1cac823e7ce54348
Issue-ID: OOM-1778
Signed-off-by: Petr Ospalý <p.ospaly@partner.samsung.com>
Signed-off-by: Michal Zegan <m.zegan@samsung.com>

4 files changed, 64 insertions, 0 deletions

diff --git a/ansible/roles/rke/tasks/main.yml b/ansible/roles/rke/tasks/main.yml
new file mode 100644
index 00000000..2f832973
--- /dev/null
+++ b/ansible/roles/rke/tasks/main.yml
@@ -0,0 +1,2 @@
+---
+- include_tasks: "rke_{{ mode }}.yml"
diff --git a/ansible/roles/rke/tasks/rke_config.yml b/ansible/roles/rke/tasks/rke_config.yml
new file mode 100644
index 00000000..49503192
--- /dev/null
+++ b/ansible/roles/rke/tasks/rke_config.yml
@@ -0,0 +1,46 @@
+---
+- name: "Ensure the .ssh directory exists"
+  file:
+    path: "{{ ansible_env.HOME }}/.ssh"
+    mode: 0700
+    state: directory
+
+- name: Add kubernetes nodes host keys to known_hosts file
+  known_hosts:
+    name: "{{ hostvars[item].cluster_ip }}"
+    key: "{{ hostvars[item].cluster_ip }} ssh-rsa {{ hostvars[item].ansible_ssh_host_key_rsa_public }}"
+    hash_host: true
+    state: present
+  loop: "{{ groups['kubernetes'] }}"
+
+- name: "Ensure {{ cluster_config_dir }} is present"
+  file:
+    path: "{{ cluster_config_dir }}"
+    state: directory
+    mode: 0755
+
+- name: Generate cluster wide ssh key pair
+  command: "ssh-keygen -q -b 4096 -t rsa -N '' -f {{ cluster_config_dir }}/cluster_key"
+  args:
+    creates: "{{ cluster_config_dir }}/cluster_key"
+
+- name: Get ssh public key
+  slurp:
+    src: "{{ cluster_config_dir }}/cluster_key.pub"
+  register: cluster_public_key_out
+
+- name: Decode ssh public key
+  set_fact:
+    cluster_public_key: "{{ cluster_public_key_out.content | b64decode }}"
+
+- name: Prepare rke cluster.yml
+  template:
+    src: cluster.yml.j2
+    dest: "{{ cluster_config_dir }}/cluster.yml"
+
+- name: Install rke cli tool
+  copy:
+    src: "{{ app_data_path }}/downloads/{{ rke_binary }}"
+    dest: "{{ rke_bin_dir }}/rke"
+    remote_src: true
+    mode: 0755
diff --git a/ansible/roles/rke/tasks/rke_deploy.yml b/ansible/roles/rke/tasks/rke_deploy.yml
new file mode 100644
index 00000000..7b3e2510
--- /dev/null
+++ b/ansible/roles/rke/tasks/rke_deploy.yml
@@ -0,0 +1,5 @@
+---
+- name: Run rke up
+  command: "{{ rke_bin_dir }}/rke up --config cluster.yml"
+  args:
+    chdir: "{{ cluster_config_dir }}"
diff --git a/ansible/roles/rke/tasks/rke_node.yml b/ansible/roles/rke/tasks/rke_node.yml
new file mode 100644
index 00000000..9ec9f073
--- /dev/null
+++ b/ansible/roles/rke/tasks/rke_node.yml
@@ -0,0 +1,11 @@
+---
+- name: Create a rke user on the node
+  user:
+    name: "{{ rke_username }}"
+    groups: docker
+    password_lock: yes
+
+- name: Distribute rke user ssh public key
+  authorized_key:
+    user: "{{ rke_username }}"
+    key: "{{ hostvars[groups['infrastructure'][0]].cluster_public_key }}"