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>

8 files changed, 277 insertions, 0 deletions

diff --git a/ansible/inventory/hosts.yml b/ansible/inventory/hosts.yml
index a29072c5..37ae4e39 100644
--- a/ansible/inventory/hosts.yml
+++ b/ansible/inventory/hosts.yml
@@ -31,6 +31,15 @@ all:
           #ip of the node that it uses for communication with k8s cluster.
           cluster_ip: 10.8.8.19
 
+    # This is a group of hosts that are to be used as kubernetes control plane nodes.
+    # This means they host kubernetes api server, controller manager and scheduler.
+    # This example uses infra for this purpose, however note that any
+    # other host could be used including kubernetes nodes.
+    # cluster_ip needs to be set for hosts used as control planes.
+    kubernetes-control-plane:
+      hosts:
+        infrastructure-server
+
     nfs-server:
       hosts:
         kubernetes-node-1
diff --git a/ansible/rke.yml b/ansible/rke.yml
new file mode 100644
index 00000000..81e964d9
--- /dev/null
+++ b/ansible/rke.yml
@@ -0,0 +1,26 @@
+---
+- name: Gather facts for all hosts
+  hosts: all
+
+- name: Configure kubernetes cluster (RKE)
+  hosts: infrastructure
+  roles:
+    - role: rke
+      vars:
+        mode: config
+
+- name: Prepare kubernetes nodes (RKE)
+  hosts:
+  - kubernetes
+  - kubernetes-control-plane
+  roles:
+    - role: rke
+      vars:
+        mode: node
+
+- name: Deploy kubernetes cluster (RKE)
+  hosts: infrastructure
+  roles:
+    - role: rke
+      vars:
+        mode: deploy
diff --git a/ansible/roles/rke/defaults/main.yml b/ansible/roles/rke/defaults/main.yml
new file mode 100644
index 00000000..3e1c26a6
--- /dev/null
+++ b/ansible/roles/rke/defaults/main.yml
@@ -0,0 +1,33 @@
+---
+rke_binary: rke
+rke_username: rke
+rke_bin_dir: /usr/local/bin
+cluster_config_dir: "{{ app_data_path }}/cluster"
+rke:
+  etcd: rancher/coreos-etcd:v3.2.24-rancher1
+  alpine: rancher/rke-tools:v0.1.27
+  nginx_proxy: rancher/rke-tools:v0.1.27
+  cert_downloader: rancher/rke-tools:v0.1.27
+  kubernetes_services_sidecar: rancher/rke-tools:v0.1.27
+  kubedns: rancher/k8s-dns-kube-dns:1.15.0
+  dnsmasq: rancher/k8s-dns-dnsmasq-nanny:1.15.0
+  kubedns_sidecar: rancher/k8s-dns-sidecar:1.15.0
+  kubedns_autoscaler: rancher/cluster-proportional-autoscaler:1.0.0
+  coredns: coredns/coredns:1.2.6
+  coredns_autoscaler: rancher/cluster-proportional-autoscaler:1.0.0
+  kubernetes: rancher/hyperkube:v1.13.5-rancher1
+  flannel: rancher/coreos-flannel:v0.10.0-rancher1
+  flannel_cni: rancher/flannel-cni:v0.3.0-rancher1
+  calico_node: rancher/calico-node:v3.4.0
+  calico_cni: rancher/calico-cni:v3.4.0
+  calico_controllers: ""
+  calico_ctl: rancher/calico-ctl:v2.0.0
+  canal_node: rancher/calico-node:v3.4.0
+  canal_cni: rancher/calico-cni:v3.4.0
+  canal_flannel: rancher/coreos-flannel:v0.10.0
+  weave_node: weaveworks/weave-kube:2.5.0
+  weave_cni: weaveworks/weave-npc:2.5.0
+  pod_infra_container: rancher/pause:3.1
+  ingress: rancher/nginx-ingress-controller:0.21.0-rancher3
+  ingress_backend: rancher/nginx-ingress-controller-defaultbackend:1.4-rancher1
+  metrics_server: rancher/metrics-server:v0.3.1
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 }}"
diff --git a/ansible/roles/rke/templates/cluster.yml.j2 b/ansible/roles/rke/templates/cluster.yml.j2
new file mode 100644
index 00000000..d55a486c
--- /dev/null
+++ b/ansible/roles/rke/templates/cluster.yml.j2
@@ -0,0 +1,145 @@
+nodes:
+{# Note that we iterate through all nodes in relevant groups.
+We check which groups they belong to exactly later to determine roles. #}
+{% for node in groups['kubernetes'] | union(groups['kubernetes-control-plane']) %}
+- address: "{{ hostvars[node].cluster_ip }}"
+  port: "22"
+  internal_address: "{{ hostvars[node].cluster_ip }}"
+  role:
+{% if node in groups['kubernetes-control-plane'] %}
+  - controlplane
+{% endif %}
+{% if node in groups['kubernetes'] %}
+  - worker
+  - etcd
+{% endif %}
+  hostname_override: ""
+  user: "{{ rke_username }}"
+  docker_socket: /var/run/docker.sock
+  ssh_key: ""
+  ssh_key_path: "{{ cluster_config_dir }}/cluster_key"
+  ssh_cert: ""
+  ssh_cert_path: ""
+  labels: {}
+{% endfor %}
+services:
+  etcd:
+    image: ""
+    extra_args: {}
+    extra_binds: []
+    extra_env: []
+    external_urls: []
+    ca_cert: ""
+    cert: ""
+    key: ""
+    path: ""
+    snapshot: null
+    retention: ""
+    creation: ""
+    backup_config: null
+  kube-api:
+    image: ""
+    extra_args: {}
+    extra_binds: []
+    extra_env: []
+    service_cluster_ip_range: 10.43.0.0/16
+    service_node_port_range: ""
+    pod_security_policy: false
+    always_pull_images: false
+  kube-controller:
+    image: ""
+    extra_args: {}
+    extra_binds: []
+    extra_env: []
+    cluster_cidr: 10.42.0.0/16
+    service_cluster_ip_range: 10.43.0.0/16
+  scheduler:
+    image: ""
+    extra_args: {}
+    extra_binds: []
+    extra_env: []
+  kubelet:
+    image: ""
+    extra_args: {}
+    extra_binds: []
+    extra_env: []
+    cluster_domain: cluster.local
+    infra_container_image: ""
+    cluster_dns_server: 10.43.0.10
+    fail_swap_on: false
+  kubeproxy:
+    image: ""
+    extra_args: {}
+    extra_binds: []
+    extra_env: []
+network:
+  plugin: canal
+  options: {}
+authentication:
+  strategy: x509
+  sans: []
+  webhook: null
+addons: ""
+addons_include: []
+system_images:
+  etcd: "{{ rke.etcd }}"
+  alpine: "{{ rke.alpine }}"
+  nginx_proxy: "{{ rke.nginx_proxy }}"
+  cert_downloader: "{{ rke.cert_downloader }}"
+  kubernetes_services_sidecar: "{{ rke.kubernetes_services_sidecar }}"
+  kubedns: "{{ rke.kubedns }}"
+  dnsmasq: "{{ rke.dnsmasq }}"
+  kubedns_sidecar: "{{ rke.kubedns_sidecar }}"
+  kubedns_autoscaler: "{{ rke.kubedns_autoscaler }}"
+  coredns: "{{ rke.coredns }}"
+  coredns_autoscaler: "{{ rke.coredns_autoscaler }}"
+  kubernetes: "{{ rke.kubernetes }}"
+  flannel: "{{ rke.flannel }}"
+  flannel_cni: "{{ rke.flannel_cni }}"
+  calico_node: "{{ rke.calico_node }}"
+  calico_cni: "{{ rke.calico_cni }}"
+  calico_controllers: ""
+  calico_ctl: "{{ rke.calico_ctl }}"
+  canal_node: "{{ rke.canal_node }}"
+  canal_cni: "{{ rke.canal_cni }}"
+  canal_flannel: "{{ rke.canal_flannel }}"
+  weave_node: "{{ rke.weave_node }}"
+  weave_cni: "{{ rke.weave_cni }}"
+  pod_infra_container: "{{ rke.pod_infra_container }}"
+  ingress: "{{ rke.ingress }}"
+  ingress_backend: "{{ rke.ingress_backend }}"
+  metrics_server: "{{ rke.metrics_server }}"
+ssh_key_path: "{{ cluster_config_dir }}/cluster_key"
+ssh_cert_path: ""
+ssh_agent_auth: false
+authorization:
+  mode: none
+  options: {}
+ignore_docker_version: false
+kubernetes_version: ""
+private_registries: []
+ingress:
+  provider: ""
+  options: {}
+  node_selector: {}
+  extra_args: {}
+cluster_name: ""
+cloud_provider:
+  name: ""
+prefix_path: ""
+addon_job_timeout: 0
+bastion_host:
+  address: ""
+  port: ""
+  user: ""
+  ssh_key: ""
+  ssh_key_path: ""
+  ssh_cert: ""
+  ssh_cert_path: ""
+monitoring:
+  provider: ""
+  options: {}
+restore:
+  restore: false
+  snapshot_name: ""
+dns: null