Orchestrating Applications with Azure Kubernetes Service (AKS)

This tutorial will guide you through the process of deploying, managing, and scaling your applications using Azure Kubernetes Service (AKS), a managed Kubernetes service provided by Microsoft Azure.

Prerequisites

Step 1: Create an AKS Cluster

If you don't already have an AKS cluster, you can create one using the Azure CLI. Replace myResourceGroup and myAKSCluster with your desired names.


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

This command creates a resource group and then an AKS cluster with one node. The monitoring add-on is enabled for better visibility.

Step 2: Connect kubectl to your AKS Cluster

To manage your cluster with kubectl, you need to get the cluster's credentials.


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

Verify the connection by listing the nodes in your cluster:


kubectl get nodes

Step 3: Deploy a Sample Application

We'll deploy a simple NGINX web server as a demonstration. Create a file named nginx-deployment.yaml with the following content:


apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:latest
        ports:
        - containerPort: 80

Apply this deployment to your cluster:


kubectl apply -f nginx-deployment.yaml

Step 4: Expose the Application

To make your application accessible from outside the cluster, you need to create a Kubernetes Service. Create a file named nginx-service.yaml:


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

Apply the service configuration:


kubectl apply -f nginx-service.yaml

It might take a few minutes for the LoadBalancer IP address to be provisioned. You can check its status with:


kubectl get service nginx-service

Once the EXTERNAL-IP is assigned, you can access your NGINX instance by browsing to that IP address in your web browser.

Step 5: Scaling Applications

Kubernetes makes it easy to scale your applications. To increase the number of NGINX pods to 5, run:


kubectl scale deployment nginx-deployment --replicas=5

You can verify the scaling by checking the deployment status:


kubectl get deployment nginx-deployment
kubectl get pods

Step 6: Updating Applications

To update your application (e.g., to a new image version), you can use kubectl set image. For example, to update to a specific NGINX version:


kubectl set image deployment/nginx-deployment nginx=nginx:1.21.6

Kubernetes will perform a rolling update, ensuring zero downtime.

Step 7: Deleting Resources

When you're finished, you can delete the application resources:


kubectl delete service nginx-service
kubectl delete deployment nginx-deployment

To delete the entire AKS cluster and its resource group:


az group delete --name myResourceGroup --yes --no-wait
Important: Remember to clean up Azure resources you are no longer using to avoid incurring unnecessary costs.

Next Steps

This tutorial covered the basics of orchestrating applications with AKS. You can explore more advanced topics such as: