MSDN Azure Tutorials

Deploy a Web Application to Azure Kubernetes Service (AKS)

This tutorial guides you through deploying a simple web application to an Azure Kubernetes Service (AKS) cluster. We'll cover creating a container image, pushing it to Azure Container Registry (ACR), and then deploying it to AKS.

Prerequisites

• An Azure account with an active subscription. If you don't have one, you can create a free account.
• The Azure CLI installed and configured.
• Docker installed and running locally.
• Kubectl installed.

Step 1: Create a Sample Web Application

First, let's create a basic web application. For this example, we'll use a simple Node.js application.

Create a new directory for your application, e.g., my-aks-app, and navigate into it.

Create a file named app.js with the following content:

const express = require('express');
const app = express();
const port = process.env.PORT || 8080;

app.get('/', (req, res) => {
  res.send('Hello from AKS!');
});

app.listen(port, () => {
  console.log(`App listening on port ${port}`);
});

Create a package.json file:

{
  "name": "my-aks-app",
  "version": "1.0.0",
  "description": "Simple web app for AKS deployment",
  "main": "app.js",
  "scripts": {
    "start": "node app.js"
  },
  "dependencies": {
    "express": "^4.17.1"
  }
}

Install the Node.js dependencies:

npm install

Step 2: Create a Dockerfile

In the same directory, create a file named Dockerfile:

# Use an official Node runtime as a parent image
FROM node:18-alpine

# Set the working directory in the container
WORKDIR /usr/src/app

# Copy package.json and package-lock.json to the working directory
COPY package*.json ./

# Install any needed packages specified in package.json
RUN npm install

# Bundle app source
COPY . .

# Make port 8080 available to the world outside this container
EXPOSE 8080

# Define environment variable
ENV PORT=8080

# Run app.js when the container launches
CMD [ "npm", "start" ]

Step 3: Build and Push the Docker Image to ACR

First, you need an Azure Container Registry (ACR). If you don't have one, create it:

az acr create --resource-group myResourceGroup --name myaksacr <unique-acr-name> --sku Basic

Login to your ACR:

az acr login --name <unique-acr-name>

Build the Docker image and tag it for ACR:

docker build -t <unique-acr-name>.azurecr.io/my-aks-app:v1 .

Push the image to ACR:

docker push <unique-acr-name>.azurecr.io/my-aks-app:v1

Step 4: Create an AKS Cluster

If you don't have an AKS cluster, create one:

az aks create --resource-group myResourceGroup --name myAKSCluster --node-count 1 --enable-addons monitoring --generate-ssh-keys

Get credentials for your AKS cluster:

az aks get-credentials --resource-group myResourceGroup --name myAKSCluster

Step 5: Deploy the Application to AKS

Create a Kubernetes deployment manifest file, e.g., deployment.yaml:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-aks-app-deployment
spec:
  replicas: 3
  selector:
    matchLabels:
      app: my-aks-app
  template:
    metadata:
      labels:
        app: my-aks-app
    spec:
      containers:
      - name: my-aks-app
        image: <unique-acr-name>.azurecr.io/my-aks-app:v1
        ports:
        - containerPort: 8080
        env:
        - name: PORT
          value: "8080"

Create a Kubernetes service manifest file, e.g., service.yaml:

apiVersion: v1
kind: Service
metadata:
  name: my-aks-app-service
spec:
  selector:
    app: my-aks-app
  ports:
    - protocol: TCP
      port: 80
      targetPort: 8080
  type: LoadBalancer

Apply the deployment and service configurations:

kubectl apply -f deployment.yaml
kubectl apply -f service.yaml

Step 6: Access Your Application

Get the external IP address of the LoadBalancer service:

kubectl get service my-aks-app-service

It might take a few minutes for the LoadBalancer to provision and assign an external IP. Once available, open a web browser and navigate to the external IP address. You should see "Hello from AKS!".

Clean Up

To avoid ongoing charges, you can delete the AKS cluster and ACR:

az group delete --name myResourceGroup --yes --no-wait