Unable to read settings from Azure App Config Service

Question

I have a working Web API in .Net 7. The Web API reads the configuration settings from appsettings.json local file and it is all working great.

Now I want to use Azure App Configuration service to store the settings. I created an Azure App Configuration service in my Azure Subscription and uploaded the local appsettings.json file. I can see all my settings there so importing also worked. While importing, I chose to use __ as the delimiter.

Now I made the following code changes in my Program.cs to read the settings from Azure:

private static IHostBuilder CreateHostBuilder(string[] args)
{
    return Host.CreateDefaultBuilder(args)
        .ConfigureWebHostDefaults(webBuilder =>
        {
            _ = webBuilder.UseStartup<Startup>();
            _ = webBuilder.ConfigureAppConfiguration((configurationBuilder) =>
            {
                configurationBuilder.Sources.Clear();
                configurationBuilder.AddAzureAppConfiguration(options =>
                {
                    options.Connect(new Uri("https://myappconfig.azconfig.io"),
                        new DefaultAzureCredential());
                }, false);
                configurationBuilder.Build();
            });
        });
}

Again, this code works fine and no errors are thrown.

However when I try to read the settings in Startup.cs file, I am not getting settings back. For example, here's the code that used to work just fine:

public void ConfigureServices(IServiceCollection services)
{
    //Inject API Settings
    var apiSettings = new ApiSettings();
    Configuration.GetSection("ApiSettings").Bind(apiSettings);
    services.AddSingleton(apiSettings);
    
    // Rest of my code
}

Previously I used to get all the fields of apiSettings getting proper values but now I am getting all of them as null.

Interestingly, when I see the value of Configuration I see all values in Data field there as shown in the screenshot below.

Can anyone please tell me what I am doing wrong?

I believe the issue is caused by using the `__` delimiter when importing. As far as I can tell, Windows environments prefer the `:` notation. Try switching over to see if it helps. — akseli, Mar 14 '23 at 16:06
@askeli - Thank you for the comment. With settings in App Service, `__` is cross-platform and `:` is Windows only and I used that as a reference when importing with `__`. It turns out that is not the case (also mentioned in the answer below). Here `:` is cross platform. Reimporting with `:` as delimiter like you suggested solved my problem. — Gaurav Mantri, Mar 14 '23 at 17:15

score 3 · Accepted Answer · answered Mar 14 '23 at 16:09

According to the documentation:

Hierarchical keys

Within the Configuration API, a colon separator (:) works on all platforms.

In environment variables, a colon separator may not work on all platforms. A double underscore, __, is supported by all platforms and is automatically converted into a colon :.

In Azure Key Vault, hierarchical keys use -- as a separator. The Azure Key Vault configuration provider automatically replaces -- with a : when the secrets are loaded into the app's configuration.

I would suggest importing the configuration using : as a separator. Because they are not environment variables, I would use the default separator.

Thank you! Changing the delimiter to `:` solved the problem. — Gaurav Mantri, Mar 14 '23 at 17:12

Unable to read settings from Azure App Config Service

1 Answers1