kubernetes-Install-Threenode-Cluster

How to Install Three node K8s cluster for on premise or local Virtual Machine for Ubuntu

Run below commands on all nodes to configure the k8s

Get the Docker gpg key

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

Add the Docker repository

sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu \
$(lsb_release -cs) \
stable"

Get the Kubernetes gpg key

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -

Add the Kubernetes repository

cat << EOF | sudo tee /etc/apt/sources.list.d/kubernetes.list
deb https://apt.kubernetes.io/ kubernetes-xenial main
EOF

Update your packages

sudo apt-get update

Install Docker, kubelet, kubeadm, and kubectl

sudo apt-get install -y docker-ce=18.06.0~ce~3-0~ubuntu kubelet=1.18.5-00 kubeadm=1.18.5-00 kubectl=1.18.5-00 

Hold them at the current version

sudo apt-mark hold docker-ce kubelet kubeadm kubectl

Add the iptables rule to sysctl.conf

echo "net.bridge.bridge-nf-call-iptables=1" | sudo tee -a /etc/sysctl.conf

Enable iptables immediately

sudo sysctl -p

Run below codes only on Master node

Initialize the cluster

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

copy the kube join command for join the worker node into cluster. use this command only on worker nodes

Set up local kubeconfig

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

Apply Calco CNI

kubectl apply -f https://docs.projectcalico.org/v3.14/manifests/calico.yaml

join the worker nodes into master node only run this command in worker node

Finally, check the master for worker nodes.

 alias kc=kubectl
 kc get nodes