How to configure Kestrel URLs in the start class

Question

I am trying to figure out the correct way to change the URLs that kestrel is listening on from the constructor of the launch class .

Update. In addition to the question below, I realized that the Startup class is not used to configure Kestrel as I thought. I thought that Startup would create a single application configuration object, which will be located through the agreement, but this is not so. As @Tseng points out, application and hosting configuration is a separate issue. The related answer and the accepted answer provide working examples.

I deployed a brand new Ubuntu 14 box to Vagrant and installed ASP.NET Core 1.1 according to current instructions from Microsoft: https://www.microsoft.com/net/core#linuxubuntu

I ran:

• dotnet new -t web
• dotnet recovery
• dotnet run

This is done by default http: // localhost: 5000 . In Program.cs, I can call app.UseUrls ("http: // *: 5001), and this works to change the URL and port.

I really want to change the URL by convention, adding a new JSON settings file to the Startup class, so I followed the examples and created a hosting.JSON file with this (note: I tried "server.urls" "and" urls "as the key).

{ urls: "http://*:5001" } 

In Startup.cs below the default lines to add the appsettings.json files, I added .AddJsonFile ("hosting.json", optional: false); (optional: false to ensure that it was collecting the file)

 public Startup(IHostingEnvironment env) { var builder = new ConfigurationBuilder() .SetBasePath(env.ContentRootPath) .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true) .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true) .AddJsonFile("hosting.json", optional: false); if (env.IsDevelopment()) { // For more details on using the user secret store see https://go.microsoft.com/fwlink/?LinkID=532709 builder.AddUserSecrets(); } builder.AddEnvironmentVariables(); Configuration = builder.Build(); } 

I checked that this parameter exists after the configuration is built, but it is not taken or is not used when the host is built in Program.cs

 public class Program { public static void Main(string[] args) { var host = new WebHostBuilder() .UseKestrel() .UseContentRoot(Directory.GetCurrentDirectory()) .UseIISIntegration() .UseStartup<Startup>() .Build(); host.Run(); } } 

and the application is still starting to listen on localhost: 5000. This is my (probably incorrect) understanding that, having correctly configured the setting with the correct key, WebHostBuidler must pick it up and use it.

I saw other examples that basically get rid of the startup class and create the configuration in Program.cs, where it can then be passed to the UseConfiguration call, but again I understand that using the Startup class should do this by convention.

Essentially I would like to leave Startup and Program separate , add the host.JSON file to the configuration with the URLs, and it was picked up and used without having to call UseUrls, UseConfiguration, etc.

Am I missing something obvious or trying to do something that is actually not right?

To explain why this is not a duplicate according to my comment:

• This article specifically states: "launcherSettings for Visual Studio F5." I use the command line in a Linux box. Nothing to do with VS.

• The solution presented in this post transferred the configuration assembly to the main method. I specifically declare that I want to create my configuration in the Startup class, as the default project "dotnet new -t web".

I do not think this is a duplicate, and I am still looking at the source of ASP.NET Core to see if this is possible.

Regarding the correct key:

https://github.com/aspnet/Hosting/blob/b6da89f54cff11474f17486cdc55c2f21f2bbd6b/src/Microsoft.AspNetCore.Hosting.Abstractions/WebHostDefaults.cs

 namespace Microsoft.AspNetCore.Hosting { public static class WebHostDefaults { public static readonly string ApplicationKey = "applicationName"; public static readonly string StartupAssemblyKey = "startupAssembly"; public static readonly string DetailedErrorsKey = "detailedErrors"; public static readonly string EnvironmentKey = "environment"; public static readonly string WebRootKey = "webroot"; public static readonly string CaptureStartupErrorsKey = "captureStartupErrors"; public static readonly string ServerUrlsKey = "urls"; public static readonly string ContentRootKey = "contentRoot"; } } 

https://github.com/aspnet/Hosting/blob/80ae7f056c08b740820ee42a7df9eae34541e49e/src/Microsoft.AspNetCore.Hosting/Internal/WebHost.cs

 public class WebHost : IWebHost { private static readonly string DeprecatedServerUrlsKey = "server.urls"; 

Answer 1

In your host.json file you should use server.urls instead of urls. And the .json hosting file needs to be added to program.cs (in the main method) not at startup.

Here is my hosts.json file.

 { "server.urls": "http://localhost:5010;http://localhost:5012" } 

Here is the main method.

 public static void Main(string[] args) { var config = new ConfigurationBuilder() .SetBasePath(Directory.GetCurrentDirectory()) .AddCommandLine(args) .AddEnvironmentVariables(prefix: "ASPNETCORE_") .AddJsonFile("hosting.json", optional: true) .Build(); var host = new WebHostBuilder() .UseConfiguration(config) .UseKestrel() .UseContentRoot(Directory.GetCurrentDirectory()) .UseIISIntegration() .UseStartup<Startup>() .Build(); host.Run(); } 

And here is a screenshot.