DevOps (K) Classroom Series – 05/Sept/2021

Kubernetes Installation

• There are many different ways of installing kuberentes and also kuberentes is readily available as a Service on Cloud (Azure Kuberentes Service, Elastic Kuberentes Service, Google Kubernetes Engine)
• To start with we would be using kubeadm as an approach to create a kubernetes cluster
• Refer Here for the installation instructions
• Lets create 3 ubuntu servers
• Now install docker on the three servers and then execute the commands as mentioned in the document Refer Here
• Now install Kube-adm, kubectl and kubelet Refer Here
• Now we can create cluster using kubeadm Refer Here
• Login into the master node

sudo -i
kubeadm init --pod-network-cidr=10.244.0.0/16

• Make a note of the instructions given which appear as shown

Your Kubernetes control-plane has initialized successfully!

To start using your cluster, you need to run the following as a regular user:

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

Alternatively, if you are the root user, you can run:

  export KUBECONFIG=/etc/kubernetes/admin.conf

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join 172.31.37.90:6443 --token q331we.xj6o2j07sy066v1r \
        --discovery-token-ca-cert-hash sha256:e281cbdb4c7de0c621e78d42d88b2bfb7d64d454afc56d3090dca3966be76ae3

• Now exit from root user to become normal user and execute the following commands on master

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

• Now login into the nodes and execute the kubeadm command as a root user
• Now login into kuberentes (k8s) and execute kubectl get nodes
• Now execute the following command to install pod network plugin

kubectl apply -f https://github.com/coreos/flannel/raw/master/Documentation/kube-flannel.yml