Azure Kubernetes Service (AKS) is a managed container orchestration service based on the open-source Kubernetes system, which is available on the Microsoft Azure public cloud. AKS simplifies deploying a managed Kubernetes cluster in Azure by offloading the operational overhead to Azure, such as health monitoring and maintenance.

• Kubernetes: An open-source platform designed to automate deploying, scaling, and operating application containers.
• Cluster: A set of nodes (virtual machines) that run containerized applications.
• Node: A single machine in the Kubernetes cluster, which can be a virtual or physical machine.
• Pod: The smallest deployable unit in Kubernetes, which can contain one or more containers.

• Managed Service: Azure handles the Kubernetes control plane, including the API server, scheduler, and other core components.
• Scaling: AKS supports both manual and automatic scaling of the cluster.
• Integration: Seamless integration with other Azure services like Azure Active Directory, Azure Monitor, and Azure DevOps.

• An active Azure subscription.
• Azure CLI installed on your local machine.

1. Login to Azure

   az login
   

2. Create a Resource Group

   az group create --name myResourceGroup --location eastus
   

3. Create an AKS Cluster

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

4. Get AKS Credentials

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

5. Verify the Cluster

   kubectl get nodes
   

1. Create a Deployment YAML File

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: my-web-app
   spec:
     replicas: 2
     selector:
       matchLabels:
         app: my-web-app
     template:
       metadata:
         labels:
           app: my-web-app
       spec:
         containers:
         - name: my-web-app
           image: nginx:1.14.2
           ports:
           - containerPort: 80
   

2. Apply the Deployment

   kubectl apply -f deployment.yaml
   

3. Expose the Deployment

   kubectl expose deployment my-web-app --type=LoadBalancer --name=my-service
   

4. Get the External IP

   kubectl get service my-service
   

1. Create a YAML file for a multi-container pod

   apiVersion: v1
   kind: Pod
   metadata:
     name: multi-container-pod
   spec:
     containers:
     - name: nginx-container
       image: nginx:1.14.2
       ports:
       - containerPort: 80
     - name: sidecar-container
       image: busybox
       command: ['sh', '-c', 'echo Hello from the sidecar! && sleep 3600']
   

2. Deploy the Pod

   kubectl apply -f multi-container-pod.yaml
   

3. Verify the Pod is Running

   kubectl get pods
   

4. Access the Logs of the Sidecar Container

   kubectl logs multi-container-pod -c sidecar-container
   

• The YAML file defines a pod with two containers: an Nginx web server and a BusyBox sidecar container.
• The kubectl apply command deploys the pod to the AKS cluster.
• The kubectl get pods command verifies that the pod is running.
• The kubectl logs command retrieves the logs from the sidecar container, demonstrating inter-container communication within the same pod.

• Resource Limits: Always define resource limits for your containers to avoid resource contention.
• Health Checks: Implement liveness and readiness probes to ensure your application is running correctly.
• Namespace Usage: Use namespaces to organize and manage resources efficiently.

In this section, you learned about Azure Kubernetes Service (AKS), how to set up an AKS cluster, and deploy applications on it. You also practiced deploying a multi-container application and learned some best practices. In the next module, we will explore Azure Functions and how to create serverless applications on Azure.