Troubleshooting DefaultAzureCredential: Identifying Which Credential Is Used
Source: Dev.to
The Problem
When using Azure Identity NuGet packages, DefaultAzureCredential will attempt to load a range of credential types such as Environment Variables, Visual Studio, Azure Managed Identity, and more. The full list is documented on Azure:
https://learn.microsoft.com/en-us/dotnet/api/azure.identity.defaultazurecredential?view=azure-dotnet
Determining which credentials are being used can be tricky unless you manually enable logging. The Microsoft‑recommended approach provides very verbose output. To simplify the output, insert the snippet below into your application’s startup.
using var listener = new AzureEventSourceListener((e, message) =>
{
if (e.EventSource.Name == "Azure-Identity")
{
Console.WriteLine(message);
// Alternatively, use _logger.LogInformation() if running in Azure
// WARNING: These logs may include sensitive credentials
// depending on the options selected below
}
},
System.Diagnostics.Tracing.EventLevel.LogAlways);
DefaultAzureCredentialOptions options = new DefaultAzureCredentialOptions
{
Diagnostics =
{
IsAccountIdentifierLoggingEnabled = true,
// Useful extra options for debugging
// These act as a whitelist of fields to log.
// LoggedHeaderNames = { "x-ms-request-id" },
// LoggedQueryParameters = { "api-version" },
// This enables logging the request or response body
// IsLoggingContentEnabled = true
}
};AzureEventSourceListener creates a verbose logger. Adding the filter above removes a lot of noise.
You should see output similar to this:
EnvironmentCredential.GetToken invoked
EnvironmentCredential.GetToken was unable to retrieve an access token
...
VisualStudioCredential.GetToken succeededThis output makes it straightforward to identify exactly which credential type was successful (or unsuccessful).
Azure Identity Logging
https://github.com/Azure/azure-sdk-for-net/blob/main/sdk/identity/Azure.Identity/README.md#logging