Kubernetes on AWS using Kops

1. Launch Linux EC2 instance in AWS (Kubernetes Client)

2. Create and attach IAM role to EC2 Instance.

Kops need permissions to access
	S3
	EC2
	VPC
	Route53
	Autoscaling
	etc..

3. 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

4. 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

5. Create S3 bucket in AWS

S3 bucket is used by kubernetes to persist cluster state, lets create s3 bucket using aws cli Note: Make sure you choose bucket name that is uniqe accross all aws accounts

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

6. Create private hosted zone in AWS Route53

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

7 Configure environment variables.

Open .bashrc file

	vi ~/.bashrc

Add following content into .bashrc, you can choose any arbitary name for cluster and make sure buck name matches the one you created in previous step.

export KOPS_CLUSTER_NAME=javahome.in
export KOPS_STATE_STORE=s3://javahome.in.k8s

Then running command to reflect variables added to .bashrc

	source ~/.bashrc

8. Create ssh key pair

This keypair is used for ssh into kubernetes cluster

ssh-keygen

9. Create a Kubernetes cluster definition.

kops create cluster \
--state=${KOPS_STATE_STORE} \
--node-count=2 \
--master-size=t3.medium \
--node-size=t3.medium \
--zones=ap-south-1a,ap-south-1b \
--name=${KOPS_CLUSTER_NAME} \
--dns private \
--master-count 1

10. Create kubernetes cluster

kops update cluster --yes --admin

Above command may take some time to create the required infrastructure resources on AWS. Execute the validate command to check its status and wait until the cluster becomes ready

kops validate cluster

For the above above command, you might see validation failed error initially when you create cluster and it is expected behaviour, you have to wait for some more time and check again.

11. To connect to the master

ssh admin@api.javahome.in

Destroy the kubernetes cluster

kops delete cluster  --yes

Update Nodes and Master in the cluster

We can change numner of nodes and number of masters using following commands

   kops edit ig nodes change minSize and maxSize to 0
   kops get ig- to get master node name
   kops edit ig - change min and max size to 0
   kops update cluster --yes
 

Optional (Create terraform scripts through kops)

  https://github.com/kubernetes/kops/blob/master/docs/terraform.md