Kubernetes NodePort Practical - Hands-on Service Exposure Tutorial

Comprehensive hands-on tutorial for Kubernetes NodePort services covering deployment exposure, external access configuration, kubectl commands, YAML examples, and practical testing with Nginx deployment

NodePort Service Example

Download the YAML configuration files for the NodePort service example

Download deploy-app.yaml Download nodeport.yaml

Deploy the App

kubectl apply -f deploy-app.yaml

Applies the configuration from the YAML file to create the Nginx deployment.

Deploy the NodePort Service

kubectl apply -f nodeport.yaml

Creates a NodePort service to expose the deployment externally.

Get the Pods List

kubectl get pods -o wide

Lists all pods with additional details including IP addresses.

Get Node Information

kubectl get nodes -o wide

Displays node information including IP addresses for accessing the service.

Cleanup - Delete Service

kubectl delete -f nodeport.yaml

Deletes the NodePort service.

Cleanup - Delete Deployment

kubectl delete -f deploy-app.yaml

Deletes the Nginx deployment and its pods.

YAML Configuration Files

deploy-app.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: deploy-nginx
  labels:
    app: nginx
    env: prod
spec:
  replicas: 2
  revisionHistoryLimit: 3
  selector:
    matchLabels:
      app: nginx
      env: prod
  template:
    metadata:
      labels:
        app: nginx
        env: prod
    spec:
      containers:
      - name: nginx
        image: nginx:alpine
        ports:
        - containerPort: 80

Deployment Configuration Explanation:

Deployment Structure:
  • apiVersion: apps/v1 → Specifies the Kubernetes API version for Deployments
  • kind: Deployment → Defines this as a Deployment resource
  • metadata.name: deploy-nginx → Names the deployment "deploy-nginx"
  • metadata.labels → Adds labels for resource identification
Deployment Spec:
  • replicas: 2 → Creates 2 identical pod instances
  • revisionHistoryLimit: 3 → Keeps 3 old ReplicaSets for rollback
  • selector.matchLabels → Defines how the Deployment finds which Pods to manage
Pod Template:
  • template.metadata.labels → Labels applied to created Pods
  • containers → Defines the container specification
  • image: nginx:alpine → Uses the lightweight Alpine-based Nginx image
  • containerPort: 80 → Exposes port 80 for web traffic

nodeport.yaml

apiVersion: v1
kind: Service
metadata:
  name: svc-example
spec:
  type: NodePort
  selector:
    app: nginx
    env: prod
  ports:
  - nodePort: 32410
    protocol: TCP
    port: 80
    targetPort: 80

NodePort Service Configuration Explanation:

Service Structure:
  • apiVersion: v1 → Specifies the Kubernetes API version for Services
  • kind: Service → Defines this as a Service resource
  • metadata.name: svc-example → Names the service "svc-example"
Service Spec:
  • type: NodePort → Exposes the service on each Node's IP at a static port
  • selector → Identifies which Pods the service should target
  • app: nginx, env: prod → Matches Pods with these labels
Port Configuration:
  • nodePort: 32410 → The port exposed on each node (30000-32767 range)
  • protocol: TCP → The network protocol (TCP/UDP)
  • port: 80 → The port the service exposes internally
  • targetPort: 80 → The port on the Pods that the service forwards to
How It Works:

The NodePort service exposes your application externally by opening a specific port (32410) on each node in your cluster. Traffic arriving at any node's IP address on this port is forwarded to the service, which then routes it to one of the Pods matching the selector labels.

With Docker Desktop, you can access the service using localhost:32410. In a cloud environment, you would use any node's IP address with port 32410.