Kubernetes On AWS Using KOPS

Introduction

Kubernetes Operations, or Kops, is an open source project used to set up Kubernetes clusters easily and swiftly. It is considered the “kubectl” way of creating clusters.

Kops allows deployment of highly available Kubernetes clusters on AWS and Google (GCP) clouds. It includes features such as dry-runs and automatic idempotency, terraform config generation making Kops a great option for do-it-yourself (DIY) developers.

Most DIY developers who like to set up clusters by themselves start by playing with minikube and then move onto Kops. For deploying small production grade clusters, Kops is one of the best tools out there. Among the numerous out-of-the-box features included with Kops are the large set of networking backends which give the user flexibility for picking and choosing the network stack that best works for their use case.

However, each of these network backends come with a myriad of configuration options and it quickly becomes complex and difficult to get those configurations right and bring a cluster up successfully.

In this article, we will demonstrate how to create Kubernetes Cluster using KOPS.

Prerequisites

• AWS EC2 Instance
• Create and attach below IAM roles to EC2 Instance,

* S3
* EC2
* VPC
* Route53
* Autoscaling

Steps to create Kubernetes Cluster Using KOPS

Step-1: Install AWS CLI

curl https://s3.amazonaws.com/aws-cli/awscli-bundle.zip -o awscli-bundle.zip
apt install unzip python
unzip awscli-bundle.zip
#sudo apt-get install unzip - if you dont have unzip in your system
./awscli-bundle/install -i /usr/local/aws -b /usr/local/bin/aws

Step-2: Install Kops on EC2

curl -LO https://github.com/kubernetes/kops/releases/download/$(curl -s https://api.github.com/repos/kubernetes/kops/releases/latest | grep tag_name | cut -d '"' -f 4)/kops-linux-amd64
chmod +x kops-linux-amd64
sudo mv kops-linux-amd64 /usr/local/bin/kops

Step-3: Install Kubectl

curl -LO https://storage.googleapis.com/kubernetes-release/release/$(curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt)/bin/linux/amd64/kubectl
chmod +x ./kubectl
sudo mv ./kubectl /usr/local/bin/kubectl

Step-4: Create S3 bucket in AWS

S3 bucket is used by Kubernetes to persist cluster state.

Create S3 bucket using AWS CLI

Note: Make sure you choose bucket name that is unique across all AWS accounts

aws s3 mb s3://tests3.in.k8s --region ap-south-1

Step-5: Create private hosted zone in AWS Route53

1. Head over to AWS Route53 and create hosted zone
2. Choose name for example (testk8s.in)
3. Choose type as private hosted zone for VPC
4. Select default VPC in the region you are setting up your cluster
5. Hit create

Step-6: Configure environment variables

Open .bashrc file

vi ~/.bashrc

Add the below content in .bashrc.

Note: You can choose any arbitrary name for cluster and make sure bucket name matches the one which we created in Step 4.

export KOPS_CLUSTER_NAME=testk8scluster.in
export KOPS_STATE_STORE=s3://tests3.in.k8s

Run the below command to reflect environment variables in the cluster

source ~/.bashrc

Step-7: Create SSH key pair

This keypair is used to SSH into Kubernetes cluster

ssh-keygen

Step-8: Create a Kubernetes cluster definition

kops create cluster \
--state=${KOPS_STATE_STORE} \
--node-count=2 \
--master-size=t2.micro \
--node-size=t2.micro \
--zones=ap-south-1a,ap-south-1b \
--name=${KOPS_CLUSTER_NAME} \
--dns private \
--master-count 1

Note: Choose appropriate values for region, zones and instance type

Step:9 Create Kubernetes Cluster

kops update cluster --yes

This may take a while to create the required AWS resources. Check the status of the Cluster using the below command and wait until the Cluster is Ready

kops validate cluster

Note: You might see validation failed error initially when you create cluster and it is expected behavior, you have to wait for some more time and check again.

Step10: Connect to the master

ssh admin@api.testk8scluster.in

Use “kubectl get nodes” command to get the details of Master Node and Worker Nodes

Master and Worker Nodes Details

Application Deployment

We have this Sample Spring Boot application in below GitHub repository,

https://github.com/senthilkumar-ps/HelloKubernetes-App.git

Step1: Dockerize the application using this DockerFile and push the image to DockerHub

Step2: Create appropriate deployment and service entries in yaml for our dockerized application

Step3: Run the below command to deploy the application

kubectl create -f hellok8s.yaml

Once our application deployed successfully, get the External-IP to access the application

kubectl get svc

Exposing Application with External IP

Step4: Navigate the URL http://External-IP:Port

HelloK8sApp

Clean Up

Delete the Kubernetes Cluster using the following command

kops delete cluster testk8scluster.in -- yes

Conclusion

We have successfully created a Kubernetes Cluster using AWS Kops and deployed a sample Spring Boot application in it. Hope you find this article useful. In the next article, we shall see how to enable Continuous Deployment on AWS with ArgoCD using Helm.