How to handle unauthenticated case when using user profile method?

[victor-ivanov]

We are using AWSSDK.Extensions.NETCore.Setup package to authenticate with AWS services.

var awsOptions = new AWSOptions
{
    Region = RegionEndpoint.USEast1,
    Profile = "some-profile-name",
};
var client = awsOptions.CreateServiceClient<IAmazonS3>();
var buckets = await client.ListBucketsAsync();

It throws following error if user is not authenticated via aws cli

System.ArgumentNullException: Value cannot be null. (Parameter 'Options property cannot be empty: ClientName')

Stack Trace: 
  SSOTokenManager.GenerateNewTokenAsync(SSOTokenManagerGetTokenOptions options, CancellationToken cancellationToken) line 623
  SSOTokenManager.GetTokenAsync(SSOTokenManagerGetTokenOptions options, CancellationToken cancellationToken) line 526
  SSOAWSCredentials.GetSsoCredentialsAsync(ICoreAmazonSSO sso) line 230
  SSOAWSCredentials.GenerateNewCredentialsAsync() line 153
  RefreshingAWSCredentials.GetCredentialsAsync() line 154
  CredentialsRetriever.InvokeAsync[T](IExecutionContext executionContext) line 99
  RetryHandler.InvokeAsync[T](IExecutionContext executionContext) line 135
  RetryHandler.InvokeAsync[T](IExecutionContext executionContext) line 150
  CallbackHandler.InvokeAsync[T](IExecutionContext executionContext) line 61
  CallbackHandler.InvokeAsync[T](IExecutionContext executionContext) line 61
  AmazonS3ExceptionHandler.InvokeAsync[T](IExecutionContext executionContext) line 57
  ErrorCallbackHandler.InvokeAsync[T](IExecutionContext executionContext) line 53
  MetricsHandler.InvokeAsync[T](IExecutionContext executionContext) line 92

Is it possible to make this code throw some kind of UnauthenticatedException if user is not logged in into cli? Or should I handle this specific System.ArgumentNullException as no auth case?

[ashishdhingra]

@victor-ivanov Good afternoon. Thanks for starting the discussion. Looks like you are using SSO profile. To use SSO profile, one needs to be authenticated via aws sso login and AWS .NET SDK takes care of the rest. In your use case, since you didn't execute AWS CLI command aws sso login, it failed while validating ClientName here. I do not see an option other than to catch System.ArgumentNullException and look out for specific exception message (which I agree is not scalable).

EDIT: I have reviewed this with the team and created an internal backlog item to use better exception classes.

Thanks,
Ashish

[ashishdhingra]

This has been addressed in AWSSDK.Core version 4.0.0-preview.12