Install Kubernetes Multinode Cluster using kubeadm

kubernetes_kubeadm_installation.sh

### Master node installation

# SSH to the first VM which will be your Master node:
ssh root@node1

# Set the Kubernetes version which will be installed:
KUBERNETES_VERSION="1.10.0"

# Set the proper CNI URL:
CNI_URL="https://raw.githubusercontent.com/coreos/flannel/v0.10.0/Documentation/kube-flannel.yml"

# For Flannel installation you need to use proper "pod-network-cidr":
POD_NETWORK_CIDR="10.244.0.0/16"

# Add the Kubernetes repository (details):
apt-get update -qq && apt-get install -y -qq apt-transport-https curl
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
tee /etc/apt/sources.list.d/kubernetes.list << EOF2
deb https://apt.kubernetes.io/ kubernetes-xenial main
EOF2

# Install necessary packages:
apt-get update -qq
apt-get install -y -qq docker.io kubelet=${KUBERNETES_VERSION}-00 kubeadm=${KUBERNETES_VERSION}-00 kubectl=${KUBERNETES_VERSION}-00

# Install Kubernetes Master:
kubeadm init --pod-network-cidr=$POD_NETWORK_CIDR --kubernetes-version v${KUBERNETES_VERSION}

# Copy the "kubectl" config files to the home directory:
test -d $HOME/.kube || mkdir $HOME/.kube
cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
chown -R $USER:$USER $HOME/.kube

# Install CNI:
export KUBECONFIG=/etc/kubernetes/admin.conf
kubectl apply -f $CNI_URL

# Your Kuberenets Master node should be ready now. You can check it using this command:
kubectl get nodes


### Worker nodes installation

# Let's connect the worker nodes now

# SSH to the worker nodes and repeat these commands on all of them in paralel:

ssh root@node2
ssh root@node3
ssh root@node4

# Set the Kubernetes version which will be installed:
KUBERNETES_VERSION="1.10.0"

# Add the Kubernetes repository (details):
apt-get update -qq && apt-get install -y -qq apt-transport-https curl
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
tee /etc/apt/sources.list.d/kubernetes.list << EOF2
deb https://apt.kubernetes.io/ kubernetes-xenial main
EOF2

# Install necessary packages:
apt-get update -qq
apt-get install -y -qq docker.io kubelet=${KUBERNETES_VERSION}-00 kubeadm=${KUBERNETES_VERSION}-00 kubectl=${KUBERNETES_VERSION}-00
exit

# All the woker nodes are prepared now - let's connect them to master node.
# SSH to the master node again and generate the "joining" command:

ssh root@node1 "kubeadm token create --print-join-command"

# You sould see something like:
-> kubeadm join <master-ip>:<master-port> --token <token> --discovery-token-ca-cert-hash sha256:<hash>

# Execute the generated command on all worker nodes...
ssh -t root@node2 "kubeadm join --token ... ... ... ... ... ..."
ssh -t root@node3 "kubeadm join --token ... ... ... ... ... ..."
ssh -t root@node4 "kubeadm join --token ... ... ... ... ... ..."

# SSH back to the master nodes and check the cluster status - all the nodes should appear there in "Ready" status after while.
ssh root@node1
# Check nodes
kubectl get nodes