Kubernetes is a powerful container orchestration system that simplifies the deployment, scaling, and management of containerized applications. Setting up a Kubernetes cluster involves configuring several key components: the control plane, worker nodes, and a load balancer with an ingress controller. In this guide, I’ll walk you through the step-by-step process of setting up a Kubernetes cluster with these essential parts.
Let’s dive right into it! 🚀
Table of Contents
- Introduction
- Setting Up the Control Plane
- Adding Worker Nodes
- Configuring Load Balancer
- Setting Up the Ingress Controller
- Final Thoughts
Introduction
Kubernetes clusters are composed of two main parts: the control plane and worker nodes.
- Control Plane: Manages the cluster and makes decisions about scheduling, scaling, and maintaining the overall state.
- Worker Nodes: Run the actual applications, with containers managed by the control plane.
- Load Balancer and Ingress Controller: Handle external traffic, distributing requests across the worker nodes, ensuring that services are accessible and highly available.
In this guide, I’ll help you configure a basic Kubernetes cluster using a control plane, worker nodes, and a load balancer with an ingress controller.
Setting Up the Control Plane
The control plane is the brain of the Kubernetes cluster, responsible for managing the cluster's lifecycle. It consists of several key components, such as the API server, etcd, scheduler, and controller manager.
Step 1: Initialize Kubernetes Control Plane
First, make sure your machine has kubeadm, kubelet, and kubectl installed. Once installed, initialize the control plane by running the following command on your master node:
sudo kubeadm init --pod-network-cidr=192.168.0.0/16
The --pod-network-cidr specifies the range of IP addresses for the pod network.
After the initialization completes, the command will output instructions on how to set up kubectl for the master node.
Step 2: Configure kubectl Access
To allow the master node to use kubectl, copy the kubeconfig file to your home directory:
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
Now, your control plane is up and running!
Adding Worker Nodes
Worker nodes are responsible for running the actual applications inside containers. You’ll need to join these worker nodes to the control plane to form a full Kubernetes cluster.
Step 3: Join Worker Nodes to the Cluster
After initializing the control plane, kubeadm will output a join command. Run this on each of your worker nodes to add them to the cluster:
sudo kubeadm join <control-plane-ip>:6443 --token <token> --discovery-token-ca-cert-hash sha256:<hash>
Make sure to replace , , and with the actual values provided by the kubeadm init command.
Step 4: Verify Nodes are Connected
Once your nodes are added, verify that they are connected to the cluster by running:
kubectl get nodes
You should see all worker nodes listed as "Ready" in the output.
Configuring Load Balancer
To ensure high availability and balanced distribution of incoming traffic, you need to set up a load balancer. This example will use MetalLB, a load balancer specifically designed for bare metal Kubernetes clusters.
Step 5: Install MetalLB
First, install MetalLB by applying the manifest:
kubectl apply -f https://raw.githubusercontent.com/metallb/metallb/v0.9.3/manifests/metallb.yaml
Next, configure a Layer 2 mode IP range for MetalLB. Create a ConfigMap for it:
apiVersion: v1
kind: ConfigMap
metadata:
namespace: metallb-system
name: config
data:
config: |
address-pools:
- name: default
protocol: layer2
addresses:
- 192.168.1.240-192.168.1.250
This IP range should be from the same network as your Kubernetes nodes, but outside the range of IPs used by your DHCP.
Step 6: Install NGINX Ingress Controller
To install the NGINX ingress controller, apply the following manifest:
kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/main/deploy/static/provider/cloud/deploy.yaml
This will create an ingress controller that listens to HTTP/HTTPS traffic and directs it based on your ingress rules.
Step 7: Create an Ingress Resource
Next, define an ingress resource for your services. Here's a sample ingress definition:
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: example-ingress
annotations:
nginx.ingress.kubernetes.io/rewrite-target: /
spec:
rules:
- host: example.com
http:
paths:
- path: /
pathType: Prefix
backend:
service:
name: example-service
port:
number: 80
Make sure your DNS is pointing to the external IP provided by the load balancer.
Final Thoughts
By following these steps, you've set up a complete Kubernetes cluster with a control plane, worker nodes, a load balancer, and an ingress controller! Kubernetes clusters can be highly complex, but understanding how the components work together simplifies the management of containerized applications.
Feel free to ask questions or leave feedback below. Happy clustering! ✨
Top comments (0)