Kubernetes playbook

This playbook was designed to get started with K8s which will give more than the minikube all in one solution.

QuickStart

1. Vagrant path

   vagrant up --no-provision - will create 4 machines (edit the servers.yml and remove 2 for the minimal installation path) ansible-galaxy install -r requirements.yml - get all the needed roles ansible-playbook -i ./inventories/vagrant_hosts ./playbooks/default.yml - runs ansible with the required vagrant inventory

2. Custom path

   1. prepare your custom servers - make sure they are Centos7
   2. Update the ./inventories/hosts file and add the required info
   3. ansible-galaxy install -r requirements.yml - get all the needed roles
   4. ansible-playbook -i ./inventories/hosts ./playbooks/default.yml - runs ansible with the required vagrant inventory

Upon completion of Ansible execution you can login (vagrant ssh || ssh k8s-master01) and run kubectl get nodes to find the list of nodes managed by the k8s master.

Caveats

• The playbook heavy relies on the inventory file and fact caching
• inventory file and corresponding nodes require 2 groups
  • k8s_masters - the list of master machines [ only tested with 1 ATM ...]
  • k8s_minions - the group of minions / worker nodes
• fact caching - in order to be able to update the /etc/hosts file on each machine I needed to store the Ansible and Host facts locally, this is achieved by a small configuration on the ansible.cfg file.

Requirements

• 2-n Virtual / cloud instances
• Ansible 2.2.2.0
• If using Vagrant path:
  • Vagrant (1.9.4)
  • Virtaulbox (5.1.22 r115126)
• If using custom infra path you will probably need an account and instances and add them to the inventory

Ansible Invntory options

Custom inventory

[k8s_masters]
k8s-master01 ansible_host=hagzag1.mydomain.com

[k8s_minions]
k8s-minion01 ansible_host=hagzag2.mydomain.com
k8s-minion02 ansible_host=hagzag3.mydomain.com

[localhost]
localhost ansible_connection=local

[all:vars]
ansible_user="user"
ansible_ssh_private_key_file="~/.ssh/id_rsa"

Vagrant inventory

[k8s_masters]
k8s-master01 ansible_host=172.16.1.2

[k8s_minions]
k8s-minion01 ansible_host=172.16.1.3
k8s-minion02 ansible_host=172.16.1.4
k8s-minion03 ansible_host=172.16.1.5

[localhost]
localhost ansible_connection=local

[all:vars]
ansible_user="vagrant"
ansible_ssh_private_key_file=".vagrant/machines/{{ inventory_hostname }}/virtualbox/private_key"

See the ./inventories in this repository for examples + the Vagrantfile and servers.yml which will enable you to create these machines for the inventory which can be found in ./inventories/vagrant_hots

Roles in use

• external see requirements.yml for details:
  • shellg.ntp nodes time synchronization
  • andrewrothstein.kubectl install kubectl on your controller | administration node
• internal see ./site-roles directory
  • ansible-role-k8s-common - common stuff such as set hostnames and add entries to /etc/hosts on each node in the cluster
  • ansible-role-k8s-base - consists of 2 set of tasks 1 for masters 1 for minions
  • ansible-role-kubectl-cfg - configure kubectl - this is used to setup a control machine to manage the k8s cluster
  • ansible-role-inventory-init - this was designed to generate an Ansible inventory. I will re-visit this at a later time once we have support for more that these 2 implementations

Example playbook

See the ./playbooks/default.yml

---
- hosts: all:!localhost
  become: true
  tasks:

- hosts: all:!localhost
  become: true
  roles:
    - role: shelleg.ntp
    - role: ansible-role-k8s-common

- hosts: k8s_masters
  become: true
  roles:
    - role: ansible-role-k8s-base
    - role: ansible-role-kubectl-cfg

- hosts: k8s_minions
  become: true
  roles:
    - role: ansible-role-k8s-base