How to Host a Kubernetes Cluster on Your Dedicated Server

How to Host a Kubernetes Cluster on Your Dedicated Server

Step 1: Prepare Your Dedicated Server

• Update the system:
  • Before starting, ensure that your server is up to date. Run the following commands:

    sudo apt-get update && sudo apt-get upgrade -y
    

  • Reboot if necessary:

    sudo reboot
    

• Install essential dependencies:
  • Ensure curl, apt-transport-https, and ca-certificates are installed:

    sudo apt-get install -y curl apt-transport-https ca-certificates
    

Step 2: Install Docker Kubernetes relies on Docker to manage containers, so you'll need to install Docker on each node in your Kubernetes cluster.

• Install Docker:

  sudo apt-get install -y docker.io
  

• Enable and start Docker:

  sudo systemctl enable docker
  sudo systemctl start docker
  

• Verify the Docker installation:

  docker --version
  

Step 3: Install Kubernetes Components You need to install kubeadm, kubelet, and kubectl, which are essential for setting up a Kubernetes cluster.

• Add the Kubernetes APT repository:

  curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
  sudo apt-add-repository "deb https://apt.kubernetes.io/ kubernetes-xenial main"
  

• Install Kubernetes components:

  sudo apt-get update
  sudo apt-get install -y kubelet kubeadm kubectl
  

Step 4: Disable Swap (Required for Kubernetes) Kubernetes requires that swap be disabled on all nodes.

• Disable swap temporarily:

  sudo swapoff -a
  

• To permanently disable swap, edit /etc/fstab and comment out any swap lines:

  sudo nano /etc/fstab
  

  • Comment out the line containing swap.
  • Save and exit the editor.

Step 5: Initialize Kubernetes Master Node Now, you’ll initialize the master node for your Kubernetes cluster.

• Initialize the Kubernetes master node:

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

  • The --pod-network-cidr flag is used to specify the range of IPs for the pods. In this case, we’re using a default CIDR block suitable for the Flannel network plugin.
• Set up kubeconfig for the current user:

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

Step 6: Install a Network Plugin A network plugin is necessary to enable communication between the Kubernetes pods. Flannel is a common choice.

• Install Flannel:

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

Step 7: Join Worker Nodes to the Cluster

• After initializing the master node, you will see a command with a token in the output, something like:

  kubeadm join <MASTER-IP>:6443 --token <your-token> --discovery-token-ca-cert-hash sha256:<your-hash>
  

  • Run this command on each worker node to join them to the Kubernetes cluster.

Step 8: Verify Cluster Nodes

• Once the worker nodes have joined, you can verify the status of the nodes in the cluster.

  kubectl get nodes
  

  • This will list all the nodes in your cluster, including the master and worker nodes.

Step 9: Deploy Applications to Your Cluster

• Create a deployment YAML file: Create a file named nginx-deployment.yaml for example, with the following content:

  apiVersion: apps/v1
  kind: Deployment
  metadata:
    name: nginx-deployment
  spec:
    replicas: 2
    selector:
      matchLabels:
        app: nginx
    template:
      metadata:
        labels:
          app: nginx
      spec:
        containers:
        - name: nginx
          image: nginx
          ports:
          - containerPort: 80
  

• Deploy the application:

  kubectl apply -f nginx-deployment.yaml
  

• Expose the deployment as a service:

  kubectl expose deployment nginx-deployment --type=LoadBalancer --name=nginx-service
  

Step 10: Access the Application

• To check if your application is running:

  kubectl get services
  

• The external IP will be shown if you are using a LoadBalancer service.

Step 11: Monitor and Manage Your Cluster

• Check the status of your pods:

  kubectl get pods
  

• Check logs for troubleshooting:

  kubectl logs <pod-name>
  

Step 12: Scale Your Application

• If you need to scale your application up or down, use the following command:

  kubectl scale deployment nginx-deployment --replicas=3
  

Step 13: Clean Up Resources

• Delete the deployment and service:

  kubectl delete deployment nginx-deployment
  kubectl delete service nginx-service