Kubespray is a combination of Ansible and Kubernetes and you can use Kubespray for deploying production ready Kubernetes clusters.
Read how to deploy a Kubernetes cluster using Kubespray .
You can manage full-lifecycle of Kubernetes clusters using Kubespray and in this demo we will see how to add new nodes to existing Kubernetes clusters.
(Photo by Albin Berlin from Pexels )
For the demo, we have a running kubernetes cluster with 1x master node and 2x worker nodes.
gini@greenmango kubespray % kubectl get nodes
NAME STATUS ROLES AGE VERSION
master-1 Ready master 3h6m v1.19.3
node-1 Ready <none> 3h5m v1.19.3
node-2 Ready <none> 3h5m v1.19.3
Step 1: Provision new Nodes
Create new nodes and make sure it is available from the machine where you have your Kubespray repository. Also configure password-less ssh key based access to new nodes.
Step 2: Update Inventory
Update inventory/mycluster/hosts.yaml with new nodes information. See below example where we have added node-3 information.
all:
hosts:
master-1:
ansible_host: 192.168.50.11
ip: 192.168.50.11
access_ip: 192.168.50.11
node-1:
ansible_host: 192.168.50.21
ip: 192.168.50.21
access_ip: 192.168.50.21
node-2:
ansible_host: 192.168.50.22
ip: 192.168.50.22
access_ip: 192.168.50.22
node-3:
ansible_host: 192.168.50.23
ip: 192.168.50.23
access_ip: 192.168.50.23
children:
kube-master:
hosts:
master-1:
kube-node:
hosts:
node-1:
node-2:
node-3:
etcd:
hosts:
master-1:
k8s-cluster:
children:
kube-master:
kube-node:
calico-rr:
hosts: {}
Step 3: Run cluster.yml to add new node to cluster
gini@greenmango kubespray % ansible-playbook \
-i inventory/mycluster/hosts.yaml \
cluster.yml -u devops -b -l node-3
Wait for playbook to be completed.
Also Read : 10 Tips for CKA & CKAD Exams
Step 4: Verify newly added node in Kubernetes cluster
Let us see if the nodes the added to Kubernetes cluster.
gini@greenmango kubespray % kubectl get nodes
NAME STATUS ROLES AGE VERSION
master-1 Ready master 4h9m v1.19.3
node-1 Ready <none> 4h8m v1.19.3
node-2 Ready <none> 4h8m v1.19.3
node-3 Ready <none> 82s v1.19.3
Here you go, new node named node-3 is part the cluster and you can schedule workload on the same.
Gineesh Madapparambath
Gineesh Madapparambath is the founder of techbeatly. He is the co-author of The Kubernetes Bible, Second Edition and the author of Ansible for Real Life Automation. He has worked as a Systems Engineer, Automation Specialist, and content author. His primary focus is on AI, Ansible Automation, Containerization (OpenShift & Kubernetes), and Infrastructure as Code (Terraform). (Read more: gineesh.com)
