C# Azure: How to set Azure timeout and retry policy when running locally?

Question

I am writing C# code that runs against an Azure cloud. My application is an ASP.NET Core web service that exposes methods but no UI.

Sometimes I want to run my code locally using Microsoft Azure Storage Emulator. When my code starts up, one of the first things that happens is this:

var container = new BlobContainerClient(_connectionString, s);
bool exists = await container.ExistsAsync(ct);
if (!exists)
    await container.CreateAsync(cancellationToken: ct);

When running locally, I sometimes forget to start Azure Storage Emulator. When that happens, it takes my code like a minute to time out and tell me it can't reach the "cloud".

What I want to achieve is: Make the program give me good error messages quickly when running locally, but use more lenient timeout strategies when actually running in the cloud.

I can reduce the above timeout by doing something like this:

var blobClientOptions = new BlobClientOptions();
blobClientOptions.Retry.MaxRetries = 0;
var container = new BlobContainerClient(_connectionString, s, blobClientOptions);

... but when running against the real cloud I don't want that; I want it to retry. One option might be to set the retries to zero like above, but only when running locally .

I have a development-specific configuration file ( appsettings.Development.json ). Is it possible to configure such timeout/retry settings in the config file?

Or is there some other best-practice way to accomplish the "fail quickly in development" behaviour that I seek?

Thanks in advance!

Answer 1

• create a class that will contain you blobstorage configuration:

public class BlobStorageConfiguration  
{
  public string ConnectionString {get; set;}
  public int MaxRetries {get; set;}
}

• in your appsettings.Development.json

{
 ...
  "BlobStorageConfiguration": {
    "ConnectionString " : "<your_connection_string>",
    "MaxRetries ":0
  }
 ...
}

• in your Startup.cs in the ConfigureServices method

..
 var blobConfig = new BlobStorageConfiguration ();
 Configuration.Bind(nameof(BlobStorageConfiguration ), blobConfig);
 services.AddSingleton(blobConfig );
..

• now you can inject your config and it will take values from the appsettings.Development.json if you are running it locally:

some controller:

[Route("api/somthing")]
[ApiController]
    public class SomethingController : ControllerBase
        private readonly ILogger<SomethingController > logger;

        public SomethingController (
            ILogger<SomethingController > logger,
            BlobStorageConfiguration blobConfig)
        {
            this.logger = logger;
         // use your blobConfig (connectionstring and maxRetries)
        }