Creating Kubernetes cluster using kubeadm on AWS

If you don’t want to be bound by integrations provided by cloud provider in its Kubernetes service, and want to create your own Kubernetes cluster over the compute instances provided by cloud provider, then below details can help.

There are multiple ways to create Kubernetes cluster, below we are using kubeadm to create cluster with single master and worker node on AWS.

AWS EC2 Instance provisioning

Launch two t2-medium instances with Ubuntu 18.04 AMI, one for master other for worker node.

Edit Security Group

Ports 6443 is opened for internal IP CIDR in security group. This port is used by worker node when joining to master.

Following installations are done on both instances.

ssh into both instances.

Need root access

sudo su

Install Docker

apt-get update && apt install docker.io -y

Install kubeadm kubelet kubectl

apt-get update && apt-get install -y apt-transport-https curl
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
cat <<EOF >/etc/apt/sources.list.d/kubernetes.list
deb https://apt.kubernetes.io/ kubernetes-xenial main
EOF
apt-get update
apt-get install -y kubelet kubeadm kubectl
apt-mark hold kubelet kubeadm kubectl

Disable swap for kubelet to work properly.

swapoff -a

Following command is run on master node.

Initialise kubeadm on master

We are using calico network plugin. It requires pod network to be in a specific IP CIDR. We need to specify that CIDR during kubeadm initialisation.

kubeadm init --pod-network-cidr=192.168.0.0/16

kubeadm init will download and install cluster control plane components.

copy the entire ‘kubeadm join’ command given at the end of kubeadm init output. It will be used to join worker node.

Export admin kubeconfig.

export KUBECONFIG=/etc/kubernetes/admin.conf

Verify component status

kubectl get componentstatus

Install calico network plugin

kubectl apply -f https://docs.projectcalico.org/v3.3/getting-started/kubernetes/installation/hosted/rbac-kdd.yaml 
kubectl apply -f https://docs.projectcalico.org/v3.3/getting-started/kubernetes/installation/hosted/kubernetes-datastore/calico-networking/1.7/calico.yaml

Following command is run on worker node.

Add worker node

Run the copied ‘kubeadm join’ command.

kubeadm join 172.31.3.36:6443 --token <token> --discovery-token-ca-cert-hash <discovery-token>

Verify on master node

Verify nodes are added

kubectl get nodes

It lists both master and worker node.

Now cluster should be UP!!!

Steps for tear down the cluster

running following commands from master

kubectl drain <worker node> --delete-local-data --force --ignore-daemonsets
kubeadm reset
iptables -F && iptables -t nat -F && iptables -t mangle -F && iptables -X

terminate the instances from AWS console.

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Originally published at gist.github.com.