Aspnetcore: Make IConfigureNamedOptions.Configure async

[aspnet-hello]

_From @damianh on Tuesday, December 5, 2017 4:22:48 AM_

Usecase: Configuring named OIDC options at runtime where one would like to make a db lookup for value.

_Copied from original issue: aspnet/Options#246_

[ajcvickers]

Triage: we are not going to implement this at this time. However, with appropriate feedback we could revisit this.

[damianh]

Well that's unfortunate. Guess I'll just have keep thus yucky code in my application 😞

    public void Configure(string name, OpenIdConnectOptions options)
    {
        var config = Task
           .Run(async () => await _config.Retrieve())
           .WaitAndUnwrapException();
        options.Authority = org.IdpConfig.Authority;
        options....
    }

[sandorfr]

@ajcvickers where would be the right place to provide use cases for this. all similar issues have been closed as not a target for 2.0 (which is perfectly fine) but there should at least be one item to discuss it and solutions.

[sandorfr]

I believe there's a growing concern (ex: https://twitter.com/davidfowl/status/1042451628316536833 )in the aspnet core team around things like MyAsyncFunc().GetAwaiter().GetResult() to synchronize async code or worse things like Task.Run(() => MyAsyncFunc()).GetAwaiter().GetResult() (https://twitter.com/davidfowl/status/1042628651450134528).

Can someone reopen this issue, or should I open a new one? Also would it be possible to make it more generic as it's the whole IOptions stack which deserve a bit more of Async friendlyness.