Using appsettings.json to configure Kestrel listen port Dotnet core 2 preview 2

Question

From what I understand the correct way of setting listen ports for ASP Dotnet Core 2 preview 1/2 is by creating a Kestrel section in the appsettings.json in the following format:

"Kestrel": {
    "EndPoints": { //Could also be Endpoints, it's a bit unclear
        "Http": {
        "Address": "127.0.0.1",
    "Port": 9001 //the port you want Kestrel to run on
},

I have tried to set up the sample webapp on a Debian machine, but when I start the app, it writes out that the app is listing on port 5000, the default port..

I know that the appsettings.json is read, because when I change the logging level to Trace, I get more info upon startup, including that no Endpoints are found and the app will use the standard 5000 port.

I have tried to search the aspnet source code on Github, and I can find a area where the Kestrel section is read from configuration (https://github.com/aspnet/Identity/blob/e38759b8a2de1b7a4a1c19462e40214b43c1cf3b/samples/IdentityOIDCWebApplicationSample/MetaPackage/KestrelServerOptionsSetup.cs), but as you can see it looks like a sample project.

What am I missing, isn't this the standard way to configure Kestrel in ASP Dotnet core 2?

Answer 1

As mentioned in a comment on the accepted answer, 2.1 has support for appsettings.json, see https://blogs.msdn.microsoft.com/webdev/2018/02/02/asp-net-core-2-1-roadmap/#security

A working appsettings.json:

"Kestrel": {
  "EndPoints": {
    "Http": {
      "Url": "http://localhost:5555"
    }
  }
}

This is for a Program.cs using (created by "dotnet new webapi"):

WebHost.CreateDefaultBuilder(args)

Relevant source code in GitHub https://github.com/aspnet/MetaPackages/blob/master/src/Microsoft.AspNetCore/WebHost.cs#L163

options.Configure(builderContext.Configuration.GetSection("Kestrel"));

and https://github.com/aspnet/MetaPackages/blob/master/src/Microsoft.AspNetCore/WebHost.cs#L169

config.AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)

Answer 2

Support for Kestrel configuration via appsettings.json has been dropped in 2.0.

See this issue comment:

kestrel config file support was cut from 2.0.0. Config values need to be read manually in your initialization code.

To get around this, you can do something like this in program.cs:

public static IWebHost BuildWebHost(string[] args) =>
 WebHost.CreateDefaultBuilder(args)
 .UseStartup < Startup > ()
 .UseKestrel((hostingContext, options) => 
 { 
  if (hostingContext.HostingEnvironment.IsDevelopment) {
   options.Listen(IPAddress.Loopback, 9001);
   options.Listen(IPAddress.Loopback, 9002, listenOptions => {
    listenOptions.UseHttps("certificate.pfx", "password");
   });
  }
 })
 .Build();

Answer 3

I am using Program.cs and hosting.json file to configure Kestrel. Example:

    var config = new ConfigurationBuilder()
                    .SetBasePath(Directory.GetCurrentDirectory())
                    .AddJsonFile("hosting.json", optional: true, reloadOnChange: true)
                    .Build();

    var host = new WebHostBuilder()
                    .UseConfiguration(config)
                    .UseKestrel()
                    .UseContentRoot(Directory.GetCurrentDirectory())
                    .UseStartup<Startup>();

hosting.json:

{
    "urls": "http://localhost:4444;http://localhost:4445;"
}

This above is an example for the latest version dotnet core.

For earlier versions:

hosting.json:

{
    "server.urls": "http://localhost:4444;http://localhost:4445;"
}