Azure authentication with the Azure SDK for Go

In this tutorial, you'll use the Default Azure Credential type from the Azure SDK for Go to authenticate to Azure with environment variables, a managed identity, or the Azure CLI.

The Azure Identity module for Go offers several different credential types that focus on OAuth with Azure Active Directory (Azure AD).

The DefaultAzureCredential type simplifies authentication by combining commonly used credentials types. It chains together type used to authenticate deployed Azure applications with credentials used to authenticate in a development environment.

default azure credential workflow

Prerequisites

  • Azure subscription: If you don't have an Azure subscription, create a free account before you begin.
  • Go installed: Version 1.18 or above

1. Install the Azure Identity module for Go

The Azure Identity module is used to authenticate to Azure.

Run the following command to download the azidentity module:

go get -u github.com/Azure/azure-sdk-for-go/sdk/azidentity

2. Authenticate with Azure

Use the DefaultAzureCredential to authenticate to Azure with one of the following techniques:

To learn more about the different credential types, see credential types.

Option 1: Define environment variables

The DefaultAzureCredential uses the EnvironmentCredential type to configure authentication using environment variables that supports three authentication types. Choose from the following authentication types and define the appropriate environment variables.

Service principal with a secret

Variable name Value
AZURE_CLIENT_ID Application ID of an Azure service principal
AZURE_TENANT_ID ID of the application's Azure AD tenant
AZURE_CLIENT_SECRET Password of the Azure service principal
export AZURE_TENANT_ID="<active_directory_tenant_id"
export AZURE_CLIENT_ID="<service_principal_appid>"
export AZURE_CLIENT_SECRET="<service_principal_password>"

Service principal with certificate

Variable name Value
AZURE_CLIENT_ID ID of an Azure AD application
AZURE_TENANT_ID ID of the application's Azure AD tenant
AZURE_CLIENT_CERTIFICATE_PATH Path to a certificate file including private key (without password protection)
export AZURE_TENANT_ID="<active_directory_tenant_id"
export AZURE_CLIENT_ID="<service_principal_appid>"
export AZURE_CLIENT_CERTIFICATE_PATH="<azure_client_certificate_path>"

Username and password

Variable name Value
AZURE_CLIENT_ID ID of an Azure AD application
AZURE_USERNAME A username (usually an email address)
AZURE_PASSWORD That user's password
export AZURE_CLIENT_ID="<service_principal_appid>"
export AZURE_USERNAME="<azure_username"
export AZURE_PASSWORD="<azure_user_password>"

Configuration is attempted in the above order. For example, if values for a client secret and certificate are both present, the client secret will be used.

Option 2: Use a managed identity

Managed identities eliminate the need for developers to manage credentials. By connecting to resources that support Azure AD authentication, applications can use Azure AD tokens instead of credentials.

If the required environment variables for the EnvironmentCredential credential type aren't present, the DefaultAzureCredential will attempt to authenticate using the ManagedIdentityCredential type.

If using a user assigned managed identity, run the following command to set the AZURE_CLIENT_ID environment variable.

export AZURE_CLIENT_ID="<user_assigned_managed_identity_client_id>"

Option 3: Sign in with Azure CLI

To support local development, the DefaultAzureCredential can authenticate as the user signed into the Azure CLI.

Run the following command to sign into the Azure CLI.

az login

The azidentity module supports authenticating through developer tools to simplify local development. Azure CLI authentication isn't recommended for applications running in Azure.

3. Use DefaultAzureCredential to authenticate ResourceClient

Create a new sample Go module named azure-auth to test authenticating to Azure with the DefaultAzureCredential.

  1. Create a directory to test and run the sample Go code, then change into that directory.

  2. Run go mod init to create a module.

    go mod init azure-auth
    
  3. Run go get to download, build, and install the necessary Azure SDK for Go modules.

    go get "github.com/Azure/azure-sdk-for-go/sdk/azidentity"
    go get "github.com/Azure/azure-sdk-for-go/sdk/resourcemanager/resources/armresources"
    
  4. Create a file named main.go and insert the following code.

    package main
    
    // Import key modules.
    import (
      "log"
    
      "github.com/Azure/azure-sdk-for-go/sdk/azidentity"
      "github.com/Azure/azure-sdk-for-go/sdk/resourcemanager/resources/armresources"
    )
    
    // Define key global variables.
    var (
      subscriptionId = "<subscription ID>"
    )
    
    // Define the function to create a resource group.
    
    func main() {
      cred, err := azidentity.NewDefaultAzureCredential(nil)
      if err != nil {
        log.Fatalf("Authentication failure: %+v", err)
      }
    
      // Azure SDK Azure Resource Management clients accept the credential as a parameter
      client := armresources.NewClient(subscriptionId, cred, nil)
    
      log.Printf("Authenticated to subscription", client)
    }
    

    Replace <subscriptionId> with your subscription ID.

  5. Run go run to build and run the app.

    go run .
    

Authenticate to Azure with DefaultAzureCredential

Use the following code in your applications to authenticate to Azure with the Azure Identity Go module using the DefaultAzureCredential credential type.

// The default credential checks environment variables for configuration.
cred, err := azidentity.NewDefaultAzureCredential(nil)
if err != nil {
  // handle error
}

// Azure SDK Azure Resource Management clients accept the credential as a parameter
client := armresources.NewClient("<subscription ID>", cred, nil)

Next steps