DefaultAzureCredential failed to retrieve a token.

Question

When attempting to read the credentials using DefaultAzureCredential(), I encounter an error intermittently, particularly after a VM restart. The specific error message is as follows, indicating that the issue is inconsistent and seems tied to the VM restart. Is there a prerequisite for executing the above function? I have created the managed identity with the required permissions.

credential = DefaultAzureCredential()

# Create the network management client
network_client = NetworkManagementClient(credential, subscription_id)

Error :

An exception occurred:' (ClientAuthenticationError("DefaultAzureCredential failed to retrieve a token from the included credentials.\nAttempted credentials:\n\tEnvironmentCredential: EnvironmentCredential authentication unavailable. Environment variables are not fully configured.\nVisit https://aka.ms/azsdk/python/identity/environmentcredential/troubleshoot to troubleshoot this issue.\n\tManagedIdentityCredential: ManagedIdentityCredential authentication unavailable, no response from the IMDS endpoint.\n\tSharedTokenCacheCredential: Shared token cache unavailable\n\tAzureCliCredential: Azure CLI not found on path\n\tAzurePowerShellCredential: PowerShell is not installed\n\tAzureDeveloperCliCredential: Azure Developer CLI could not be found. Please visit https://aka.ms/azure-dev for installation instructions and then,once installed, authenticate to your Azure account using 'azd auth login'.\nTo mitigate this issue, please refer to the troubleshooting guidelines here at https://aka.ms/azsdk/python/identity/defaultazurecredential/troubleshoot."),)

Answer 1

Hello Diksha Singh

I believe you are using Managed Identity Authentication DefaultAzureCredential and ManagedIdentityCredential support managed identity authentication in any hosting environment which supports managed identities, such as (this list is not exhaustive):

• Azure Virtual Machines
• Azure App Service
• Azure Kubernetes Service
• Azure Cloud Shell
• Azure Arc
• Azure Service Fabric

DefaultAzureCredential and EnvironmentCredential can be configured with environment variables. Each type of authentication requires values for specific variables:

AZURE_CLIENT_ID	id of an Azure Active Directory application
AZURE_TENANT_ID	id of the application’s Azure Active Directory tenant
AZURE_CLIENT_SECRET	one of the application’s client secrets

Managed Identity flow

from azure.identity import ManagedIdentityCredential

credential = ManagedIdentityCredential()

# Can also specify a client ID of a user-assigned managed identity
credential = ManagedIdentityCredential(
    client_id="<client_id>",
)

https://azuresdkdocs.blob.core.windows.net/$web/python/azure-identity/1.6.0/index.html