Exception when running ServiceBusTrigger with managed identity locally

[mpec]

Description

When we run our functions that use ServiceBus Trigger locally we get an error log, but the function continues to run and connects to ServiceBus.

The error we see is:

False MSAL 4.56.0.0 MSAL.NetCore .NET 6.0.26 Microsoft Windows 10.0.22631 [2024-04-04 11:20:59Z - a5b037bc-4ded-4814-93cc-b888ba93c78f] Exception type: Azure.Identity.CredentialUnavailableException
[2024-04-04T11:20:59.554Z] ---> Inner Exception Details
[2024-04-04T11:20:59.554Z] Exception type: System.AggregateException
[2024-04-04T11:20:59.555Z] ---> Inner Exception Details
[2024-04-04T11:20:59.556Z] Exception type: Azure.RequestFailedException
[2024-04-04T11:20:59.557Z] ---> Inner Exception Details
[2024-04-04T11:20:59.558Z] Exception type: System.Net.Http.HttpRequestException
[2024-04-04T11:20:59.558Z] ---> Inner Exception Details
[2024-04-04T11:20:59.559Z] Exception type: System.Net.Sockets.SocketException
[2024-04-04T11:20:59.560Z]
[2024-04-04T11:20:59.560Z]    at System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.ThrowException(SocketError error, CancellationToken cancellationToken)
[2024-04-04T11:20:59.561Z]    at System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.System.Threading.Tasks.Sources.IValueTaskSource.GetResult(Int16 token)
[2024-04-04T11:20:59.562Z]    at System.Net.Sockets.Socket.<ConnectAsync>g__WaitForConnectWithCancellation|277_0(AwaitableSocketAsyncEventArgs saea, ValueTask connectTask, CancellationToken cancellationToken)
[2024-04-04T11:20:59.562Z]    at System.Net.Http.HttpConnectionPool.ConnectToTcpHostAsync(String host, Int32 port, HttpRequestMessage initialRequest, Boolean async, CancellationToken cancellationToken)
[2024-04-04T11:20:59.563Z] === End of inner exception stack trace ===
[2024-04-04T11:20:59.564Z]
[2024-04-04T11:20:59.564Z]    at System.Net.Http.HttpConnectionPool.ConnectToTcpHostAsync(String host, Int32 port, HttpRequestMessage initialRequest, Boolean async, CancellationToken cancellationToken)
[2024-04-04T11:20:59.565Z]    at System.Net.Http.HttpConnectionPool.ConnectAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
[2024-04-04T11:20:59.566Z]    at System.Net.Http.HttpConnectionPool.CreateHttp11ConnectionAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
[2024-04-04T11:20:59.566Z]    at System.Net.Http.HttpConnectionPool.AddHttp11ConnectionAsync(HttpRequestMessage request)
[2024-04-04T11:20:59.567Z]    at System.Threading.Tasks.TaskCompletionSourceWithCancellation`1.WaitWithCancellationAsync(CancellationToken cancellationToken)
[2024-04-04T11:20:59.568Z]    at System.Net.Http.HttpConnectionPool.GetHttp11ConnectionAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
[2024-04-04T11:20:59.568Z]    at System.Net.Http.HttpConnectionPool.SendWithVersionDetectionAndRetryAsync(HttpRequestMessage request, Boolean async, Boolean doRequestAuth, CancellationToken cancellationToken)
[2024-04-04T11:20:59.569Z]    at System.Net.Http.HttpClient.<SendAsync>g__Core|83_0(HttpRequestMessage request, HttpCompletionOption completionOption, CancellationTokenSource cts, Boolean disposeCts, CancellationTokenSource pendingRequestsCts, CancellationToken originalCancellationToken)
[2024-04-04T11:20:59.570Z]    at Azure.Core.Pipeline.HttpClientTransport.ProcessAsync(HttpMessage message, Boolean async)
[2024-04-04T11:20:59.570Z] === End of inner exception stack trace ===
[2024-04-04T11:20:59.571Z]
[2024-04-04T11:20:59.572Z]    at Azure.Core.Pipeline.HttpClientTransport.ProcessAsync(HttpMessage message, Boolean async)
[2024-04-04T11:20:59.572Z]    at Azure.Core.Pipeline.HttpPipelineTransportPolicy.ProcessAsync(HttpMessage message, ReadOnlyMemory`1 pipeline)
[2024-04-04T11:20:59.573Z]    at Azure.Core.Pipeline.ResponseBodyPolicy.ProcessAsync(HttpMessage message, ReadOnlyMemory`1 pipeline, Boolean async)
[2024-04-04T11:20:59.574Z]    at Azure.Core.Pipeline.LoggingPolicy.ProcessAsync(HttpMessage message, ReadOnlyMemory`1 pipeline, Boolean async)
[2024-04-04T11:20:59.575Z]    at Azure.Core.Pipeline.RedirectPolicy.ProcessAsync(HttpMessage message, ReadOnlyMemory`1 pipeline, Boolean async)
[2024-04-04T11:20:59.575Z]    at Azure.Core.Pipeline.RetryPolicy.ProcessAsync(HttpMessage message, ReadOnlyMemory`1 pipeline, Boolean async)
[2024-04-04T11:20:59.576Z] === End of inner exception stack trace ===
[2024-04-04T11:20:59.577Z]
[2024-04-04T11:20:59.577Z]    at Azure.Core.Pipeline.RetryPolicy.ProcessAsync(HttpMessage message, ReadOnlyMemory`1 pipeline, Boolean async)
[2024-04-04T11:20:59.578Z]    at Azure.Identity.ManagedIdentitySource.AuthenticateAsync(Boolean async, TokenRequestContext context, CancellationToken cancellationToken)
[2024-04-04T11:20:59.579Z]    at Azure.Identity.ImdsManagedIdentitySource.AuthenticateAsync(Boolean async, TokenRequestContext context, CancellationToken cancellationToken)
[2024-04-04T11:20:59.579Z] === End of inner exception stack trace ===
[2024-04-04T11:20:59.580Z]
[2024-04-04T11:20:59.580Z]    at Azure.Identity.ImdsManagedIdentitySource.AuthenticateAsync(Boolean async, TokenRequestContext context, CancellationToken cancellationToken)
[2024-04-04T11:20:59.581Z]    at Azure.Identity.ManagedIdentityClient.AuthenticateCoreAsync(Boolean async, TokenRequestContext context, CancellationToken cancellationToken)
[2024-04-04T11:20:59.582Z]    at Azure.Identity.ManagedIdentityClient.AppTokenProviderImpl(AppTokenProviderParameters parameters)
[2024-04-04T11:20:59.583Z]    at Microsoft.Identity.Client.Internal.Requests.ClientCredentialRequest.SendTokenRequestToAppTokenProviderAsync(ILoggerAdapter logger, CancellationToken cancellationToken)
[2024-04-04T11:20:59.583Z]    at Microsoft.Identity.Client.Internal.Requests.ClientCredentialRequest.GetAccessTokenAsync(CancellationToken cancellationToken, ILoggerAdapter logger)
[2024-04-04T11:20:59.584Z]    at Microsoft.Identity.Client.Internal.Requests.ClientCredentialRequest.ExecuteAsync(CancellationToken cancellationToken)
[2024-04-04T11:20:59.585Z]    at Microsoft.Identity.Client.Internal.Requests.RequestBase.RunAsync(CancellationToken cancellationToken)

My local config for service bus is:
"ServiceBusTriggerConnection__fullyQualifiedNamespace": "xxx-yyy-local.servicebus.windows.net",

The example function signature where we see this:
[Function(nameof(DeleteContentFunction))]public async Task Run([ServiceBusTrigger("%DeleteContentTopic%", "%DeleteContentSubscription%", Connection = "ServiceBusTriggerConnection")] string messageString)

We aren't sure why we get this error, but I confirmed that it's showing up only in case of SB Trigger and managed identity.

Steps to reproduce

Run function locally.

[enijburg]

I can confirm this issue is happening in all of our .NET isolated function apps created with .NET 8 when running locally.
It does not matter if we use ConfigureFunctionsWorkerDefaults or ConfigureFunctionsWebApplication.

[gitFire001]

The issue is happening even with the Python functions running locally.

[adae-palfinger]

Also having this issue

[ThomasDejbjerg]

I can confirm that this also happens on our .NET isolated function apps, and that setting ExcludeManageIdentity do not change the outcome, it still tries to get the token from ManagedIdentity.

[enzosambucetti]

I can also confirm that is happening to us, in isolated mode, net 8.0, with ConfigureFunctionsWebApplication() and ConfigureFunctionsWorkerDefaults().
Any ideas?

[ibis7]

Also having this issue running Az Function locally