This guide will show you how to set up a small Kubernetes cluster with 1 master node and 2 worker nodes on Ubuntu 18.04.
Please install followed packaged on all nodes:
Install Docker #
Prepare packages
$ apt-get update
$ apt-get install \
apt-transport-https \
ca-certificates \
curl \
gnupg \
lsb-release
Add GPG keys:
$ curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg –dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg
Add docker.io repo:
$ echo \
“deb [arch=amd64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu \
$(lsb_release -cs) stable” | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
Install docker and docker-compose:
$ apt-get update
$ apt-get install docker-ce docker-ce-cli containerd.io docker-compose
Start docker.io:
$ service docker start
Now you need to check docker cgroup:
$ docker info | grep -i cgroup
If it’s not systemd, we need to change it. Please creating file /etc/docker/daemon.json and paste following content:
{
“exec-opts”: [“native.cgroupdriver=systemd”]
}
Now restart docker:
$ systemctl restart docker
Kubernetes #
Add GPG keys:
$ curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add
Add Kubernetes repo:
$ apt-add-repository “deb http://apt.kubernetes.io/ kubernetes-xenial main”
Install kubeadm (1.19)
$ apt install kubeadm=1.19.14-00 kubelet=1.19.14-00 kubectl=1.19.14-00 kubernetes-cni
Prevent Kubernetes updates
$ apt-mark hold kubelet kubeadm kubectl
On a master node:
Initialize your Kubernetes master node:
$ kubeadm init
Before you start joining to the master node on worker nodes, you need to copy kube config into your /root/.kube directory:
$ mkdir -p $HOME/.kube
$ cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
$ chown $(id -u):$(id -g) $HOME/.kube/config
Network installation
Now install network driver (Weave Net):
$ kubectl apply -f “https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d ‘\n’)”
On worker nodes:
Before you use kubeadm join command on your worker nodes, please edit /etc/hosts file and provide on all nodes IP address and hostname of all existing nodes.
Now use kubeadm join command on worker nodes and wait for deployment.
On a master node:
Now check your nodes:
$ kubectl get nodes -A
LoadBalancer Metallb installation
If your nodes are ready, you can now install LoadBalancer inside your cluster:
$ kubectl apply -f https://raw.githubusercontent.com/metallb/metallb/v0.10.2/manifests/namespace.yaml
$ kubectl apply -f https://raw.githubusercontent.com/metallb/metallb/v0.10.2/manifests/metallb.yaml
Ingress Nginx installation
Now we need to install an ingress controller:
$ kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/main/deploy/static/provider/baremetal/deploy.yaml
(Optional) Kubernetes Dashboard #
If you would like to visualize your Kubernetes Cluster, you can install the official dashboard:
$ kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v2.2.0/aio/deploy/recommended.yaml
You can reach it from your web browser, however, it needs a few steps:
Service account – please create file service-account.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
name: service-account
namespace: kube-system
Service role – please create file service-role.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: service-account
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: cluster-admin
subjects:
– kind: ServiceAccount
name: service-account
namespace: kube-system
Now apply both files:
$ kubectl apply -f service-account.yaml
$ kubectl apply -f service-role.yaml
Now you need to get your auth token:
$ kubectl -n kube-system get secrets | grep service-account
Copy your service account name and type:
$ kubectl -n kube-system describe secret service-account-{random}
Copy TOKEN and save it. You will use it to authorize inside Kubernetes Dashboard.
Now re-login to master node with SSH tunneling:
$ ssh root@k8s-master -L 8001:localhost:8001
Now run kubectl proxy:
$ kubectl proxy &
Open now your web browser and paste the following URL:
http://localhost:8001/api/v1/namespaces/kubernetes-dashboard/services/https:kubernetes-dashboard:/proxy/#/login
Your Kubernetes cluster is ready!
