This is a simple walk-through so you can setup a local cluster up and running. Cloud platforms have their own versions of Kubernetes where master node is usually a managed service and the worker nodes are compute machines. I have avoided putting in specific version numbers to just give you an idea of the install process.
In the future, I believe each OS will have seamless way to install Kubernetes with pre-built installation packages. Now, let us stick with a basic test cluster to play around with.
In my cluster, there are 3 VMs with Ubuntu as the OS
ubuntu1 – will act as the master node
ubuntu 2 & 3 – worker nodes
Ensure you can ssh into the boxes, and you are ready to run the commands. Make sure you have unique MAC and product_uuid in case you have cloned VMs. Each machine should have a dedicated ip.
These commands should be run on all 3 nodes
— Regular package update
sudo apt-get update
— Update for https repo access
sudo apt-get install -y apt-transport-https curl
— Add key for the new repository. Make sure you add the sudo command before your apt-key add
sudo curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
— Now, add the repo
sudo vim /etc/apt/sources.list.d/kubernetes.list
deb http://apt.kubernetes.io/ kubernetes-xenial main
— Install Kubernetes and Kubernetes networking CNI
sudo apt-get update
sudo apt-get install -y kubelet kubeadm kubectl
— The networking aspect now. Pick any of your favorite, but for this cluster, I will pick flannel. You can also use weave net as well
kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
— Let’s install docker,
sudo apt install docker.io -y
— Verify install is working by running these commands
Now, the real fun starts with assigning ubuntu1 as the master node, how do we do that? Execute the command. You can actually add flags to set the token not to expire, but let us keep this simple
sudo kubeadm init
— Follow the instructions on the screen to execute the following commands
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
— Execute this command on the worker nodes (your security token will be different).
kubeadm join 192.168.198.132:6443 --token iptt5e.hszynj998ztugg47 \
--discovery-token-ca-cert-hash sha256:331560a34e8a1e8b4001462e951e2d502bfe9a3c73279b43ebae7365835a30e3 --skip-preflight-checks
Now, after the command is executed on the worker nodes, we can run the following command to make sure, the cluster is operational. Look for the status of Ready on the nodes
sudo kubectl get nodes
If you encounter issues, do a check on the specific node.
kubectl describe nodes ubuntu1
In the future posts, we will build up on this cluster and deploy some sample applications. Helm as the package manager has a lot of features that we can explore along with the k8 dashboard.