kubernetes project #1

Source: Dev.to

Overview

Run a single containerized web app in Kubernetes and access it from your browser:

Flow: Browser → Service → Pod → Container

This exercise demonstrates:

• What a Pod is
• Why Kubernetes exists
• How traffic reaches a container
• How Kubernetes networking differs from Docker

Understanding this will clarify many other Kubernetes concepts.

Prerequisites

• Minikube (local Kubernetes) installed
• kubectl installed
• Docker installed

Start Minikube:

minikube start

Verify the node is ready:

kubectl get nodes

Expected output

NAME       STATUS   ROLES           AGE   VERSION
minikube   Ready    control-plane   ...   ...

Kubernetes always runs workloads on nodes, so a node must be available.

Create a Pod

Create a file named pod.yaml:

apiVersion: v1
kind: Pod
metadata:
  name: hello-pod
  labels:
    app: hello
spec:
  containers:
  - name: hello-container
    image: nginx
    ports:
    - containerPort: 80

Apply the manifest:

kubectl apply -f pod.yaml

Check that the Pod is running:

kubectl get pods

Describe the Pod to see details such as the assigned IP, container status, and events:

kubectl describe pod hello-pod

Key points

• A Pod is the smallest unit Kubernetes runs (it can contain one or more containers).
• Pods receive a unique IP address, but that IP is not stable.

Expose the Pod with a Service

Create a file named service.yaml:

apiVersion: v1
kind: Service
metadata:
  name: hello-service
spec:
  type: NodePort
  selector:
    app: hello
  ports:
  - port: 80
    targetPort: 80
    nodePort: 30007

Apply the Service:

kubectl apply -f service.yaml

Verify the Service:

kubectl get svc

The Service provides a stable endpoint (NodePort) that forwards traffic to the Pod, regardless of the Pod’s changing IP.

Access the Application

Retrieve Minikube’s IP address:

minikube ip

Open a browser and navigate to:

http://<minikube-ip>:30007

You should see the default Nginx welcome page:

Welcome to nginx!

This confirms that the web app is running in Kubernetes and reachable from outside the cluster.

Cleanup

Delete the Pod:

kubectl delete pod hello-pod

Confirm it’s gone:

kubectl get pods

The Pod disappears, illustrating why Pods alone are not production‑ready—they do not self‑heal when they fail.

Core Concepts Recap

Understanding Pods, Services, and Labels sets the foundation for using Deployments, which handle pod lifecycle and scaling in production environments.