Edit

Tutorial: Run applications in Azure Kubernetes Service (AKS)

  • Article

Kubernetes provides a distributed platform for containerized applications. You build and deploy your own applications and services into a Kubernetes cluster and let the cluster manage the availability and connectivity. In this tutorial, part four of seven, you deploy a sample application into a Kubernetes cluster. You learn how to:

  • Update a Kubernetes manifest file.
  • Run an application in Kubernetes.
  • Test the application.

In later tutorials, you'll scale out and update your application.

This quickstart assumes you have a basic understanding of Kubernetes concepts. For more information, see Kubernetes core concepts for Azure Kubernetes Service (AKS).

Tip

AKS clusters can use GitOps for configuration management. GitOp enables declarations of your cluster's state, which are pushed to source control, to be applied to the cluster automatically. To learn how to use GitOps to deploy an application with an AKS cluster, see the prerequisites for Azure Kubernetes Service clusters in the GitOps with Flux v2 tutorial.

Before you begin

In previous tutorials, you packaged an application into a container image, uploaded the image to Azure Container Registry, and created a Kubernetes cluster.

To complete this tutorial, you need the pre-created azure-vote-all-in-one-redis.yaml Kubernetes manifest file. This file download was included with the application source code in a previous tutorial. Verify that you've cloned the repo and that you've changed directories into the cloned repo. If you haven't done these steps and would like to follow along, start with Tutorial 1: Prepare an application for AKS.

This tutorial requires that you're running the Azure CLI version 2.0.53 or later. Run az --version to find the version. If you need to install or upgrade, see Install Azure CLI.

Update the manifest file

In these tutorials, an Azure Container Registry (ACR) instance stores the container image for the sample application. To deploy the application, you must update the image name in the Kubernetes manifest file to include the ACR login server name.

Get the ACR login server name using the az acr list command.

az acr list --resource-group myResourceGroup --query "[].{acrLoginServer:loginServer}" --output table

The sample manifest file from the git repo you cloned in the first tutorial uses the images from Microsoft Container Registry (mcr.microsoft.com). Make sure you're in the cloned azure-voting-app-redis directory, and then open the manifest file with a text editor, such as vi:

vi azure-vote-all-in-one-redis.yaml

Replace mcr.microsoft.com with your ACR login server name. You can find the image name on line 60 of the manifest file. The following example shows the default image name:

containers:
- name: azure-vote-front
  image: mcr.microsoft.com/azuredocs/azure-vote-front:v1

Provide your own ACR login server name so your manifest file looks similar to the following example:

containers:
- name: azure-vote-front
  image: <acrName>.azurecr.io/azure-vote-front:v1

Save and close the file. In vi, use :wq.

Deploy the application

To deploy your application, use the kubectl apply command, specifying the sample manifest file. This command parses the manifest file and creates the defined Kubernetes objects.

kubectl apply -f azure-vote-all-in-one-redis.yaml

The following example output shows the resources successfully created in the AKS cluster:

$ kubectl apply -f azure-vote-all-in-one-redis.yaml

deployment "azure-vote-back" created
service "azure-vote-back" created
deployment "azure-vote-front" created
service "azure-vote-front" created

Test the application

When the application runs, a Kubernetes service exposes the application front end to the internet. This process can take a few minutes to complete.

To monitor progress, use the kubectl get service command with the --watch argument.

kubectl get service azure-vote-front --watch

Initially the EXTERNAL-IP for the azure-vote-front service shows as pending.

azure-vote-front   LoadBalancer   10.0.34.242   <pending>     80:30676/TCP   5s

When the EXTERNAL-IP address changes from pending to an actual public IP address, use CTRL-C to stop the kubectl watch process. The following example output shows a valid public IP address assigned to the service:

azure-vote-front   LoadBalancer   10.0.34.242   52.179.23.131   80:30676/TCP   67s

To see the application in action, open a web browser to the external IP address of your service.

Screenshot showing the container image Azure Voting App running in an AKS cluster opened in a local web browser

If the application doesn't load, it might be an authorization problem with your image registry. To view the status of your containers, use the kubectl get pods command. If you can't pull the container images, see Authenticate with Azure Container Registry from Azure Kubernetes Service.

Next steps

In this tutorial, you deployed a sample Azure vote application to a Kubernetes cluster in AKS. You learned how to:

  • Update a Kubernetes manifest file.
  • Run an application in Kubernetes.
  • Test the application.

In the next tutorial, you'll learn how to scale a Kubernetes application and the underlying Kubernetes infrastructure.

Scale Kubernetes application and infrastructure