MinimalAPI configuration reload do not update the the options value

[WeihanLi]

Describe the bug

When I use the MinimalAPI, I met an issue that the value of the options could not get updated when I try to reload the configuration via IConfigurationRoot.Reload(), I'm not sure if this is by design.

Sample code is as below:

var builder = WebApplication.CreateBuilder(args);
builder.Services.Configure<SettingsOption>(builder.Configuration);
var app = builder.Build();

var logger = app.Services.GetRequiredService<ILoggerFactory>()
    .CreateLogger("Test");
app.Map(new PathString("/redeploy"), appBuilder => appBuilder.Run(context =>
{
    var config = context.RequestServices.GetRequiredService<IConfiguration>();
    logger.LogInformation($"Configuration in redeploy hash code: {config.GetHashCode()}");
    if (config is IConfigurationRoot configuration)
    {
        var currentSlot = configuration["Setting1"];
        configuration["Setting1"] = "Slot2" != currentSlot ? "Slot2" : "Slot1";
        configuration.Reload();
        return context.Response.WriteAsync("Success");
    }
    logger.LogWarning($"configuration is not configuration root, configurationType: {config.GetType().FullName}");
    return Task.CompletedTask;
}));
app.MapFallback(context =>
{
    var option = context.RequestServices.GetRequiredService<IOptionsMonitor<SettingsOption>>();
    return context.Response.WriteAsJsonAsync(new{ option.CurrentValue.Setting1, Time= DateTime.Now });
});
app.Run();

When I access the redeploy endpoint, the value of the option should be updated I think.

More

After some research, I found that the builder.Configuration and IConfiguration from DI are not the same instance, so when I call reload, the option's value did not update, maybe this is by design? I'm not sure so I created this issue.

To Reproduce

There's a simple sample for reproducing the issue, https://github.com/WeihanLi/AspNetCorePlayground/tree/master/MinimalAPIConfigurationIssue

1. Run dotnet run
2. Access the endpoint http://localhost:5000
3. Access the endpoint http://localhost:5000/redeploy
4. Reply step 2, access http:localhost:5000 again

Expected behavior:

The setting1 value from the response should be Slot2

Actucal behavior:

The setting1 value from the response keep as null

Further technical details

• ASP.NET Core version: .NET 6 Preview 5
• Include the output of dotnet --info
  

[halter73]

This might be fixed by #33082

[WeihanLi]

Thanks @halter73, maybe I should close this issue now or wait for the fix?

[halter73]

Let's keep it open for now @WeihanLi. This provides a good test case, so thanks! I'll close it once I confirmed it's fixed.

[halter73]

Thanks again for the report @WeihanLi. It turns out this was fixed by #33081 in preview6 which is now available.

I feel it's kind of cheating because we simply register WebApplicationBuilder.Configuration as an IConfiguration service after the inner HostBuilder's IConfiguration.

aspnetcore/src/DefaultBuilder/src/WebApplicationBuilder.cs

Lines 47 to 48 in 632b241

	// Register Configuration as IConfiguration so updates can be observed even after the WebApplication is built.
	Services.AddSingleton<IConfiguration>(Configuration);

This works when the IConfiguration is resolved from DI by middleware as is done in this sample, but there are some places where the inner HostBuilder is still using it's own _hostConfiguration, so it would be best to also use a ChainedConfigurationSource as suggested by #33082. I'll continue tracking that with this issue.

[WeihanLi]

it would be best to also use a ChainedConfigurationSource as suggested by #33082

Agree with this, thanks @halter73