AKS

Managed Kubernetes

Azure Kubernetes Service (AKS) Tutorial

Azure Kubernetes Service (AKS) is a managed Kubernetes service that simplifies deploying, managing, and scaling containerized applications in Azure. This guide covers creating an AKS cluster, deploying an application, and managing resources.

Introduction to AKS
Prerequisites
Creating an AKS Cluster
Connecting to the AKS Cluster
Deploying an Application to AKS
Scaling and Updating the Application
Monitoring and Logging

Introduction to AKS

AKS is a managed Kubernetes service that handles the Kubernetes control plane, allowing you to focus on deploying and managing applications without worrying about infrastructure.

Benefits of AKS

Managed Control Plane: Azure manages Kubernetes master node operations.
Scaling: Automatically scales nodes and pods based on demand.
Integrated Security: Integrates with Azure Active Directory for secure access.
Monitoring: Built-in Azure Monitor integration for tracking performance.

Prerequisites

Azure CLI: Install the Azure CLI if you haven’t already. Download it here.
Azure Subscription: Ensure you have an active Azure subscription.

az login

Creating an AKS Cluster

Set Environment Variables (optional):

   RESOURCE_GROUP=myResourceGroup
   CLUSTER_NAME=myAKSCluster
   LOCATION=eastus

Create a Resource Group:

az group create --name $RESOURCE_GROUP --location $LOCATION

Create the AKS Cluster:

  az aks create --resource-group $RESOURCE_GROUP --name $CLUSTER_NAME --node-count 3 --enable-addons monitoring --generate-ssh-keys

This command creates a 3-node AKS cluster with monitoring enabled.

Connecting to the AKS Cluster

Install kubectl (if not already installed):

az aks install-cli

Connect to the Cluster:

az aks get-credentials --resource-group $RESOURCE_GROUP --name $CLUSTER_NAME

Verify Connection:

kubectl get nodes

Deploying an Application to AKS

Create a Deployment:

kubectl create deployment my-app --image=nginx

Expose the Deployment:

kubectl expose deployment my-app --port=80 --type=LoadBalancer

Check the Service IP:

kubectl get service my-app

Scaling and Updating the Application

Scale the Deployment:

kubectl scale deployment my-app --replicas=5

Update the Deployment (e.g., change the image):

kubectl set image deployment/my-app nginx=nginx:1.19.0

Check the Status of the Update:

kubectl rollout status deployment/my-app

Monitoring and Logging

Enabling AKS Monitoring

When creating the AKS cluster with the --enable-addons monitoring flag, AKS integrates with Azure Monitor.

View Cluster Metrics: Go to the Azure Portal, navigate to your AKS cluster, and select Insights under Monitoring to view performance metrics and set alerts.
Access Logs: Logs for containers and nodes are available through Azure Monitor for troubleshooting and resource management.

Sample Azure Devops Yaml file

trigger:
- master  # Adjust according to your branch name

variables:
  imageName: nippy/myimage  # The base name for the Docker image
  imageTag: $(Build.BuildId)  # Automatically uses the build ID as the image tag

jobs:
- job: BuildAndDeploy
  pool:
    vmImage: 'ubuntu-latest'
  
  steps:
  - task: Docker@2
    inputs:
      containerRegistry: 'dockerhub'  # Reference to your Docker Hub service connection
      repository: '$(imageName)'  # Image name to build and push
      command: 'buildAndPush'  # Command to build and push the Docker image
      Dockerfile: '**/Dockerfile'  # Path to your Dockerfile
      tags: '$(imageTag)'  # Tag for the Docker image, using the build ID

  - script: |
      ls -l  # List files to verify the environment
      echo "Building Kubernetes deployment manifest..."
      sed "s|{{imageTag}}|$(imageTag)|g" deployment.yaml > deployment_replaced.yaml  # Replace placeholder with actual image tag
      cat deployment_replaced.yaml      
    displayName: 'Replace image tag in deployment.yaml'

  - task: Kubernetes@1
    inputs:
      connectionType: 'Azure Resource Manager'  # Using Azure Resource Manager for connection
      azureSubscriptionEndpoint: 'Free Trial(1)(98391885-1dc7-4963-93d0-7590a267b3f7)'  # Your Azure subscription
      azureResourceGroup: 'azure-devops'  # Resource group containing the AKS cluster
      kubernetesCluster: 'dev09'  # Name of the AKS cluster
      namespace: 'default'  # Kubernetes namespace to deploy into
      command: 'apply'  # Command to apply the configuration
      useConfigurationFile: true  # Indicate that a configuration file will be used
      configuration: 'deployment_replaced.yaml'  # The updated deployment file to apply
      secretType: 'dockerRegistry'  # Type of secret for authentication
      containerRegistryType: 'Azure Container Registry'  # Type of container registry being used

AKS