Aspire and App Configuration and Sentinel values

[rrussell0]

Hi - I've just set up App Configuration via Aspire and hooked it into some of my services and it's working as expected, except for live-refreshing the configuration. Does anyone have any sample projects where they got this to work? For context, here's an example of how I'm doing it in my Program.cs:

// Adds Azure App Configuration with Keyvault if it's configured in Aspire AppHost

var appConfigConnString = builder.Configuration.GetConnectionString("myapp-appconfig");

if (!string.IsNullOrWhiteSpace(appConfigConnString))

{

    // Setting up Key Vault client for Azure Key Vault integration with App Configuration

    // Important: Key Vault-backed secrets cannot be referenced before var app = builder.Build(); in the Program.cs

    builder.AddAzureKeyVaultClient(connectionName: "myapp-kv");

    // Initializing and configuring Azure App Configuration

    builder.AddAzureAppConfiguration(

    connectionName: "myapp-appconfig",

    configureOptions: options =>
    {
        options.Select("*", labelFilter: "core-service");
        options.ConfigureRefresh(refresh =>
        {
            // Sets up sentinel value for refreshing configuration
            refresh.Register("RefreshKey", label: "core-service", refreshAll: true);
        });
        options.ConfigureKeyVault(kv =>
        {
            kv.SetCredential(new DefaultAzureCredential());
        });
    });
    Console.WriteLine($"Configuration loaded from: {appConfigConnString}");
}

Later in the Program.cs, I made a test endpoint that ideally should return the updated value when the RefreshKey is updated:

var app = builder.Build();

// Endpoint to test App Configuration refresh with the 'RefreshTest' key
app.MapGet("/config-refresh-test", (IConfiguration config) =>
{
    var value = config["RefreshTest"];
    return Microsoft.AspNetCore.Http.Results.Ok(new { RefreshTest = value ?? "(not found)" });
});

I'm new to this, so forgive me if I'm missing something very fundemental.

[engineering87]

Hello @rrussell0,
here are the key bits you’re missing for live refresh with Azure App Configuration in an Aspire app:

• Add the middleware after var app = builder.Build();

var app = builder.Build();
app.UseAzureAppConfiguration();

• Register a refresh sentinel and a cache window when adding App Config, for example:

builder.AddAzureAppConfiguration("myapp-appconfig", options => {
    options.Select("*", "core-service");
    options.ConfigureRefresh(r =>
        r.Register("RefreshKey", label: "core-service", refreshAll: true)
         .SetCacheExpiration(TimeSpan.FromSeconds(5)));
});

• Trigger a refresh before reading values for testing purpose:

app.MapGet("/config-refresh-test",
async (IConfiguration config, IConfigurationRefresherProvider refresherProvider) =>
{
    await refresherProvider.Refreshers.First().TryRefreshAsync();
    return Results.Ok(new { RefreshTest = config["RefreshTest"] ?? "(not found)" });
});

• Ensure labels match ("core-service") for both RefreshKey and RefreshTest.