This documentation is for the most recent version of GKE on Azure, released in November 2021. See the Release notes for more information.

Create an Azure Active Directory application

In this section, you create an Azure Active Directory (Azure AD) application and service principal objects. GKE on Azure uses these objects to store configuration information on Azure.

To create the Azure AD application, run the following command:
```
az ad app create --display-name APPLICATION_NAME
```
Replace APPLICATION_NAME with a name for your application—for example, anthos-clusters.
To save the application's ID to an environment variable for later use, run the following command:
```
APPLICATION_ID=$(az ad app list --all \
 --query "[?displayName=='APPLICATION_NAME'].appId" \
 --output tsv)
```
Replace APPLICATION_NAME with the name of your application.
To create a service principal for the application, run the following command:
```
az ad sp create --id "${APPLICATION_ID}"
```

Set up Workload identity federation

Workload identity federation allows GKE on Azure to authenticate to Azure using a Google service account. This method of authenticating to Azure is simpler than the legacy AzureClient authentication method, which requires you to manage certificates and manually upload them to Azure Active Directory (AD).

To configure a federated identity credential on your Azure AD application, run the following commands. Note that you can add up to twenty credentials to each Azure AD application.

Create a JSON file named credential.json.

{
  "name": "CREDENTIAL_NAME",
  "issuer": "https://accounts.google.com",
  "subject": "service-PROJECT_NUMBER@gcp-sa-gkemulticloud.iam.gserviceaccount.com",
  "audiences": ["api://AzureADTokenExchange"],
  "description": "Allow GKE on Azure to authenticate to the Azure AD application using a Google service account."
}

CREDENTIAL_NAME: the credential name.
PROJECT_NUMBER: the number of the Google Cloud project that hosts the cluster.

Create a federated identity credential on the Azure AD application:

az ad app federated-credential create --id "${APPLICATION_ID}" --parameters credential.json

For more details, see the Azure documentation Azure AD workload identity federation with Google Cloud.

You can also provision the Azure federated identity credential using Terraform. For details, see azuread_application_federated_identity_credential.

What's next

Create Azure role assignments