.NET Core 2.0 BasePath Error

Question

Just started a fresh .NET Core 2.0 app, but getting weird sudden behaviour, can't seem to find anything.

The following error pops up when hitting the .Run() of my BuildWebHost().:

System.InvalidOperationException: A path base can only be configured using IApplicationBuilder.UsePathBase().
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.<BindAddressAsync>d__7.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.AddressesStrategy.<BindAsync>d__2.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.<BindAsync>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer.<StartAsync>d__21`1.MoveNext()
'dotnet.exe' (CoreCLR: clrhost): Loaded 'C:\Program Files\dotnet\shared\Microsoft.NETCore.App\2.0.0\System.Diagnostics.Tools.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
Application Insights Telemetry (unconfigured): {"name":"Microsoft.ApplicationInsights.Dev.Exception","time":"2017-09-25T13:26:29.6923656Z","tags":{"ai.application.ver":"1.0.0.0","ai.internal.sdkVersion":"aspnet5c:2.1.1"},"data":{"baseType":"ExceptionData","baseData":{"ver":2,"properties":{"{OriginalFormat}":"Unable to start Kestrel.","CategoryName":"Microsoft.AspNetCore.Server.Kestrel","Exception":"System.InvalidOperationException: A path base can only be configured using IApplicationBuilder.UsePathBase().\r\n   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.<BindAddressAsync>d__7.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.AddressesStrategy.<BindAsync>d__2.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.<BindAsync>d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer.<StartAsync>d__21`1.MoveNext()","AspNetCoreEnvironment":"Development","DeveloperMode":"true"},"exceptions":[{"id":47609378,"typeName":"System.InvalidOperationException","message":"Unable to start Kestrel.","hasFullStack":true,"parsedStack":[{"level":0,"method":"Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder+<BindAddressAsync>d__7.MoveNext","assembly":"Microsoft.AspNetCore.Server.Kestrel.Core, Version=2.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60"},{"level":1,"method":"System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw","assembly":"System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e"},{"level":2,"method":"System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification","assembly":"System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e"},{"level":3,"method":"Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder+AddressesStrategy+<BindAsync>d__2.MoveNext","assembly":"Microsoft.AspNetCore.Server.Kestrel.Core, Version=2.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60"},{"level":4,"method":"System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw","assembly":"System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e"},{"level":5,"method":"System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification","assembly":"System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e"},{"level":6,"method":"Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder+<BindAsync>d__0.MoveNext","assembly":"Microsoft.AspNetCore.Server.Kestrel.Core, Version=2.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60"},{"level":7,"method":"System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw","assembly":"System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e"},{"level":8,"method":"System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification","assembly":"System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e"},{"level":9,"method":"Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer+<StartAsync>d__21`1.MoveNext","assembly":"Microsoft.AspNetCore.Server.Kestrel.Core, Version=2.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60"}]}],"severityLevel":"Critical"}}}
The thread 0x1d7c has exited with code 0 (0x0).
The thread 0x25c0 has exited with code 0 (0x0).
Exception thrown: 'System.InvalidOperationException' in System.Private.CoreLib.dll
An unhandled exception of type 'System.InvalidOperationException' occurred in System.Private.CoreLib.dll
A path base can only be configured using IApplicationBuilder.UsePathBase().

Here's my Program.cs

public class Program
{
    public static void Main(string[] args)
    {
        BuildWebHost(args).Run();
    }

    public static IWebHost BuildWebHost(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            .UseStartup<Startup>()
            .Build();
}

Here's my Startup.cs

public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public IConfiguration Configuration { get; set; }

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddMvc();

        //Swagger
        services.AddSwaggerGen(c =>
        {
            c.SwaggerDoc("v1", new Info
            {
                Title = "2Commit Blogpost API",
                Version = "v1"
            });
        });

        //Mediatr
        services.AddScoped<IMediator, Mediator>();
        services.AddTransient<SingleInstanceFactory>(sp => sp.GetService);
        services.AddTransient<MultiInstanceFactory>(sp => sp.GetServices);
        services.AddMediatorHandlers(typeof(Startup).Assembly);

        //MongoDB
        services.Configure<MongoSettings>(s =>
        {
            s.Database = Configuration.GetSection("MongoConnection:Database").Value;
        });
        services.AddSingleton<IMongoClient, MongoClient>(client => new MongoClient(Configuration.GetSection("MongoConnection:ConnectionString").Value));

        //BL
        services.AddTransient<IUserService, UserService>();

        //DAL
        services.AddTransient<IRepository, MongoRepository>();
    }

    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        //Swagger
        app.UseSwagger();
        app.UseSwaggerUI(c =>
        {
            c.SwaggerEndpoint("/swagger/v1/swagger.json", "BlogPost API");
        });

        app.UseMvc();
    }
}

Can't seem to wrap my head around this one!

UPDATE 1 :

The error only pops up when running my project from the command line, when running it trough IIS Express, no errors.

Here are my launchSettings

{
  "iisSettings": {
    "windowsAuthentication": false,
    "anonymousAuthentication": true,
    "iisExpress": {
      "applicationUrl": "http://localhost:51592/swagger",
      "sslPort": 0
    }
  },
  "profiles": {
    "IIS Express": {
      "commandName": "IISExpress",
      "launchBrowser": true,
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    },
    "API": {
      "commandName": "Project",
      "launchBrowser": true,
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      },
      "applicationUrl": "http://localhost:5000/swagger"
    }
  }
}

Answer 1

OK, in 1.X you could just add a base path to your applicationUrl in your launchOptions while running from command line, now it only works when using IIS.

in my launchSettings, changing my CLI profile from using

"applicationUrl": "http://localhost:5000/swagger"

to

"applicationUrl": "http://localhost:5000"

did the trick.

Answer 2

As @TanguyB said, you should change applicationUrl But then you may set

"launchUrl": "http://localhost:5000/swagger"

to run your application on Swagger page

Answer 3

I am using Core 3.0: I removed https url and kept only http url