# Test your Next.js deployment ## Prerequisites Before you begin, make sure you've completed the following: - Complete all the previous sections of this guide, starting with [Containerize Next.js application](containerize.md). - [Enable Kubernetes](manuals/desktop/use-desktop/kubernetes.md#enable-kubernetes) in Docker Desktop. > **New to Kubernetes?** > Visit the [Kubernetes basics tutorial](https://kubernetes.io/docs/tutorials/kubernetes-basics/) to get familiar with how clusters, pods, deployments, and services work. --- ## Overview This section guides you through deploying your containerized Next.js application locally using [Docker Desktop's built-in Kubernetes](/docker.docs-ja/desktop/kubernetes/). Running your app in a local Kubernetes cluster allows you to closely simulate a real production environment, enabling you to test, validate, and debug your workloads with confidence before promoting them to staging or production. --- ## Create a Kubernetes YAML file Follow these steps to define your deployment configuration: 1. In the root of your project, create a new file named: nextjs-sample-kubernetes.yaml 2. Open the file in your IDE or preferred text editor. 3. Add the following configuration, and be sure to replace `{DOCKER_USERNAME}` and `{DOCKERHUB_PROJECT_NAME}` with your actual Docker Hub username and repository name from the previous [Automate your builds with GitHub Actions](configure-github-actions.md). ```yaml apiVersion: apps/v1 kind: Deployment metadata: name: nextjs-sample namespace: default spec: replicas: 1 selector: matchLabels: app: nextjs-sample template: metadata: labels: app: nextjs-sample spec: containers: - name: nextjs-container image: {DOCKER_USERNAME}/{DOCKERHUB_PROJECT_NAME}:latest imagePullPolicy: Always ports: - containerPort: 3000 env: - name: NODE_ENV value: "production" - name: HOSTNAME value: "0.0.0.0" --- apiVersion: v1 kind: Service metadata: name: nextjs-sample-service namespace: default spec: type: NodePort selector: app: nextjs-sample ports: - port: 3000 targetPort: 3000 nodePort: 30001 ``` This manifest defines two key Kubernetes resources, separated by `---`: - Deployment Deploys a single replica of your Next.js application inside a pod. The pod uses the Docker image built and pushed by your GitHub Actions CI/CD workflow (refer to [Automate your builds with GitHub Actions](configure-github-actions.md)). The container listens on port `3000`, which is the default port for Next.js applications. - Service (NodePort) Exposes the deployed pod to your local machine. It forwards traffic from port `30001` on your host to port `3000` inside the container. This lets you access the application in your browser at [http://localhost:30001](http://localhost:30001). > [!NOTE] > To learn more about Kubernetes objects, see the [Kubernetes documentation](https://kubernetes.io/docs/home/). --- ## Deploy and check your application Follow these steps to deploy your containerized Next.js app into a local Kubernetes cluster and verify that it's running correctly. ### Step 1. Apply the Kubernetes configuration In your terminal, navigate to the directory where your `nextjs-sample-kubernetes.yaml` file is located, then deploy the resources using: ```console $ kubectl apply -f nextjs-sample-kubernetes.yaml ``` If everything is configured properly, you'll see confirmation that both the Deployment and the Service were created: ```shell deployment.apps/nextjs-sample created service/nextjs-sample-service created ``` This output means that both the Deployment and the Service were successfully created and are now running inside your local cluster. ### Step 2. Check the Deployment status Run the following command to check the status of your deployment: ```console $ kubectl get deployments ``` You should see an output similar to: ```shell NAME READY UP-TO-DATE AVAILABLE AGE nextjs-sample 1/1 1 1 14s ``` This confirms that your pod is up and running with one replica available. ### Step 3. Verify the Service exposure Check if the NodePort service is exposing your app to your local machine: ```console $ kubectl get services ``` You should see something like: ```shell NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE nextjs-sample-service NodePort 10.100.244.65 3000:30001/TCP 1m ``` This output confirms that your app is available via NodePort on port 30001. ### Step 4. Access your app in the browser Open your browser and navigate to [http://localhost:30001](http://localhost:30001). You should see your production-ready Next.js Sample application running — served by your local Kubernetes cluster. ### Step 5. Clean up Kubernetes resources Once you're done testing, you can delete the deployment and service using: ```console $ kubectl delete -f nextjs-sample-kubernetes.yaml ``` Expected output: ```shell deployment.apps "nextjs-sample" deleted service "nextjs-sample-service" deleted ``` This ensures your cluster stays clean and ready for the next deployment. --- ## Summary In this section, you learned how to deploy your Next.js application to a local Kubernetes cluster using Docker Desktop. This setup allows you to test and debug your containerized app in a production-like environment before deploying it to the cloud. What you accomplished: - Created a Kubernetes Deployment and NodePort Service for your Next.js app - Used `kubectl apply` to deploy the application locally - Verified the app was running and accessible at `http://localhost:30001` - Cleaned up your Kubernetes resources after testing --- ## Related resources Explore official references and best practices to sharpen your Kubernetes deployment workflow: - [Kubernetes documentation](https://kubernetes.io/docs/home/) – Learn about core concepts, workloads, services, and more. - [Deploy on Kubernetes with Docker Desktop](manuals/desktop/use-desktop/kubernetes.md) – Use Docker Desktop's built-in Kubernetes support for local testing and development. - [`kubectl` CLI reference](https://kubernetes.io/docs/reference/kubectl/) – Manage Kubernetes clusters from the command line. - [Kubernetes Deployment resource](https://kubernetes.io/docs/concepts/workloads/controllers/deployment/) – Understand how to manage and scale applications using Deployments. - [Kubernetes Service resource](https://kubernetes.io/docs/concepts/services-networking/service/) – Learn how to expose your application to internal and external traffic.