Rapid Deployment of a Kubernetes Cluster with Ansible

Utilize Ansible and Vagrant to rapidly deploy a Kubernetes cluster in a Test environment.

The Kubernetes cluster we will create is shown in the diagram above. It consists of three vagrant nodes kube nodes

• k8smaster
• k8snode1
• k8snode2

These servers are located in different subnets compared to your development machine ansible node

• devbuild

Getting Started

Follow these steps to implement the setup:

Provision VMs

Login into your ansible node

vagrant up
vagrant ssh devbuild

Change the root password for ansible node and switch to root

sudo passwd
su - 

Update the package manager and install Git

apt update
apt install git -y

Download this repository to devbuild machine, access ansible and bash scripts

cd /
git clone https://github.com/odennav/kubeadm-ansible-ubuntu.git
cd kubeadm-ansible-ubuntu

Generate SSH public/private key pair

ssh-keygen -t rsa -b 4096

Once the RSA key-pair is generated, manually copy the public key id_rsa.pub to the /root/.ssh/authorized_keys file in all kube nodes.

Install Ansible in devbuild

sudo apt install -y software-properties-common
sudo add-apt-repository --yes --update ppa:ansible/ansible
sudo apt install -y ansible

The bootstrap and k8s folders in this repository contain the Ansible scripts necessary to set up your servers with the required packages and applications.

Bootstrapping Vagrant Nodes

All nodes will be bootstrapped using Ansible.

Bootstrap the master node

cd kubeadm-ansible-ubuntu/bootstrap/
ansible-playbook bootstrap.yml --limit k8s_master

Bootstrap the worker nodes

ansible-playbook bootstrap.yml --limit k8s_node

Once the bootstrap is complete, you can log in as odennav-admin.

Confirm SSH access to master node

ssh  odennav-admin@192.168.50.2

Confirm SSH access to 1st worker node

ssh  odennav-admin@192.168.50.3

To return to devbuild, type exit and press Enter or use Ctrl+D

Confirm SSH access to 2nd worker node

ssh  odennav-admin@192.168.50.4

Setting up Kubernetes Cluster

Your kube nodes are now ready to have a Kubernetes cluster installed on them.

Execute playbooks in this particular order:

cd ../kubeadm
ansible-playbook k8s.yml  --limit k8s_master
ansible-playbook k8s.yml  --limit k8s_node

Check status of your nodes

kubectl get nodes

Your Kubernetes cluster is ready.

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Enjoy!