Goal: Setup a 3-Nodes Cluster with 1 master and 2 worker nodes
Pre-requisites:
A Minimum of 2 GM of RAM available to all VMs
A minimum of 2 CPUs are recommended
Network connectivity between VMs
Ubuntu 16+
* You can still create the cluster even if you don’t meet the above CPU and memory recommendation, you have to force the Kube cluster to force ignore the pre-requisites check.
Steps (Use root account):
Provision the VMs by using any solution like Vagrant, AWS, or Azure.
Install br_netfilter on each VM if it’s not installed already.
*Run on all the nodes in the cluster
To check:
lsmod | grep br_netfilter
To Install:
sudo modprobe br_netfilter
Run the following command
cat <<EOF | sudo tee /etc/modules-load.d/k8s.conf
br_netfilter
EOF
cat <<EOF | sudo tee /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sudo sysctl --system
Installing container runtime (Docker) on all the nodes/VMs.
*Run on all the nodes in the cluster
Docker Installation:
## Set up the docker repository:
sudo apt-get update && sudo apt-get install -y \
apt-transport-https ca-certificates curl
software-properties-common gnupg2
# Add Docker's official GPG key:
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key --keyring /etc/apt/trusted.gpg.d/docker.gpg add -
# Add the Docker apt repository:
sudo add-apt-repository \
"deb [arch=amd64] https://download.docker.com/linux/ubuntu \
$(lsb_release -cs) \
stable"
Install Docker CE
sudo apt-get update && sudo apt-get install -y \
containerd.io=1.2.13-2 \
docker-ce=5:19.03.11~3-0~ubuntu-$(lsb_release -cs) \
docker-ce-cli=5:19.03.11~3-0~ubuntu-$(lsb_release -cs)
## Create /etc/docker
sudo mkdir /etc/docker
# Set up the Docker daemon
cat <<EOF | sudo tee /etc/docker/daemon.json
{
"exec-opts": ["native.cgroupdriver=systemd"],
"log-driver": "json-file",
"log-opts": {
"max-size": "100m"
},
"storage-driver": "overlay2"
}
EOF
# Create /etc/systemd/system/docker.service.d
sudo mkdir -p /etc/systemd/system/docker.service.d
# Restart Docker
sudo systemctl daemon-reload
sudo systemctl restart docker
# Enable docker to start at boot
sudo systemctl enable docker
Install Kubeadm, Kubectl and Kubelet
*Run on all the nodes in the cluster
sudo apt-get update && sudo apt-get install -y apt-transport-https curl
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
cat <<EOF | sudo tee /etc/apt/sources.list.d/kubernetes.list
deb https://apt.kubernetes.io/ kubernetes-xenial main
EOF
sudo apt-get update
sudo apt-get install -y kubelet kubeadm kubectl
sudo apt-mark hold kubelet kubeadm kubectl
Initialize the Master Control-Plane on the Master node
*Run on the master node only
kubeadm init --pod-network-cidr 10.244.0.0/16 --apiserver-advertise-address=<ipaddressOfmasternode>
Add the following option if you don’t meet the memory & CPU requirement, it will force ignore the check.
--ignore-preflight-errors=all
You can give any cider range for the pod network, just make sure it’s not the same cider ranges as your VMs.
Make a record of the kubeadm join command that kubeadm init outputs. You need this command to join nodes to your cluster
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) $HOME/.kube/config
Install the Pod Network Add-on so that nodes can communicate with each other in the Kubernetes cluster. We are using the Weavenet network add-on here.
kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')"
Run the following Command on Work Nodes only to join the Kube Master node.
Run the Kubeadm Join command that you got from Kubeadm Init command output in the
step 5.
Example only:
kubeadm join 10.0.0.11:6443 --token lkjxey.hl6v0iuhtq76s3py --discovery-token-ca-cert-hash sha256:eedaaa9b1e1094ef29ba9c41a0db1be3a5baa27d49ac43d467dcab4583627ff3
Add the following option if your join command is failing due to not meeting the memory & CPU etc. requirement, it will force ignore the check.
--ignore-preflight-errors=all
Run the following command to test if all nodes are ready in your cluster.
kubectl get nodes -o wide
If you see all node status as Ready, your Kubernetes cluster is ready to be used.
Pat on your back!
