Expose WebHostBuilderContext in UseKestrel

[Tratcher]

#1334 @halter73 I've poached this because it will make the configuration work easier.

[JunTaoLuo]

Should this null check be added to the extension above as well?

[Tratcher]

services.Configure does that check.

[JunTaoLuo]

I don't think the sample app builds

[JunTaoLuo]

This doesn't look right

[davidfowl]

I wonder if this would be better to put on the KestrelServerOptions object itself.

[Tratcher]

                .UseKestrel(options =>
                  {
                    var basePort = options.HostContext.Configuration.GetValue<int?>("BASE_PORT") ?? 5000;
                    if (options.HostContext.HostingEnvironment.IsDevelopment()) { ... }

shrug

It may mess up services.Configure<KestrelServerOptions>(options => ...), or you'd have to capture it like you capture the services today.

[davidfowl]

It may mess up services.Configure(options => ...), or you'd have to capture it like you capture the services today.

Is the WebHostBuilderContext in the container?

[Tratcher]

No

[davidfowl]

Then this is fine