ANCM InProcess startup failed because of invalid runtimeconfig.json

The application is deployed as an (32-bit, .NET Core 2.2) App Service on Azure. It works fine when using the standard AspNetCoreModule instead of the newer AspNetCoreModuleV2 that supports the InProcess hostingmodel.

When using the new InProcess hostingmodel, the actual error is

Could not find inprocess request handler. Captured output from invoking hostfxr: Invalid runtimeconfig.json [D:\home\site\wwwroot\Foo.Api.runtimeconfig.json] [D:\home\site\wwwroot\Foo.Api.runtimeconfig.dev.json]

Foo.Api.runtimeconfig.json at wwwroot location

{
  "runtimeOptions": {
    "tfm": "netcoreapp2.2",
    "framework": {
      "name": "Microsoft.AspNetCore.App",
      "version": "2.2.0"
    },
    "configProperties": {
      "System.GC.Server": true
    }
  }
}

Web.config

<configuration>
  <location path="." inheritInChildApplications="false">
    <system.webServer>
      <handlers>
        <add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModuleV2" resourceType="Unspecified" />
      </handlers>
      <aspNetCore processPath="dotnet" arguments=".\Foo.Api.dll" stdoutLogEnabled="true" stdoutLogFile=".\logs\stdout" hostingModel="InProcess">
           <handlerSettings>
               <handlerSetting name="debugLevel" value="file" />
               <handlerSetting name="debugFile" value=".\logs\ancm.log" />
           </handlerSettings>
      </aspNetCore>
    </system.webServer>
  </location>
</configuration>

ANCM logfile

[aspnetcorev2.dll] Initializing logs for 'D:\Program Files (x86)\IIS\Asp.Net Core Module\V2\aspnetcorev2.dll'. Process Id: 12324.. File Version: 12.2.18296.0. Description: IIS ASP.NET Core Module V2. Commit: 61f1a70784dc0a32cf98f8ddd169c0293b0390ab.
[aspnetcorev2.dll] Detected app_offline file, creating polling application
[aspnetcorev2.dll] Application went offline
[aspnetcorev2.dll] Resolving hostfxr parameters for application: 'dotnet' arguments: '.\Foo.Api.dll' path: 'D:\home\site\wwwroot\'
[aspnetcorev2.dll] Known dotnet.exe location: ''
[aspnetcorev2.dll] Process path 'dotnet.exe' is dotnet, treating application as portable
[aspnetcorev2.dll] Resolving absolute path to dotnet.exe from 'dotnet.exe'
[aspnetcorev2.dll] Invoking where.exe to find dotnet.exe
[aspnetcorev2.dll] where.exe invocation returned: 'D:\Program Files (x86)\dotnet\dotnet.exe
D:\Program Files\dotnet\dotnet.exe
'
[aspnetcorev2.dll] Current process bitness type detected as isX64=0
[aspnetcorev2.dll] Processing entry 'D:\Program Files (x86)\dotnet\dotnet.exe'
[aspnetcorev2.dll] Binary type 0
[aspnetcorev2.dll] Found dotnet.exe via where.exe invocation at 'D:\Program Files (x86)\dotnet\dotnet.exe'
[aspnetcorev2.dll] Resolving absolute path to hostfxr.dll from 'D:\Program Files (x86)\dotnet\dotnet.exe'
[aspnetcorev2.dll] hostfxr.dll located at 'D:\Program Files (x86)\dotnet\host\fxr\2.2.0\hostfxr.dll'
[aspnetcorev2.dll] Converted argument '.\Foo.Api.dll' to 'D:\home\site\wwwroot\.\Foo.Api.dll'
[aspnetcorev2.dll] Parsed hostfxr options: dotnet location: 'D:\Program Files (x86)\dotnet\dotnet.exe' hostfxr path: 'D:\Program Files (x86)\dotnet\host\fxr\2.2.0\hostfxr.dll' arguments:
[aspnetcorev2.dll] Argument[0] = 'D:\Program Files (x86)\dotnet\dotnet.exe'
[aspnetcorev2.dll] Argument[1] = 'D:\home\site\wwwroot\.\Foo.Api.dll'
[aspnetcorev2.dll] Event Log: 'Invoking hostfxr to find the inprocess request handler failed without finding any native dependencies. This most likely means the app is misconfigured, please check the versions of Microsoft.NetCore.App and Microsoft.AspNetCore.App that are targeted by the application and are installed on the machine.' 
End Event Log Message.
[aspnetcorev2.dll] Failed HRESULT returned: 0x8000ffff at c:\b\w\e37dd45d8cd1eaf4\modules\iisintegration\src\aspnetcoremodulev2\aspnetcore\handlerresolver.cpp:80 
[aspnetcorev2.dll] Event Log: 'Could not find inprocess request handler. Captured output from invoking hostfxr: Invalid runtimeconfig.json [D:\home\site\wwwroot\Foo.Api.runtimeconfig.json] [D:\home\site\wwwroot\Foo.Api.runtimeconfig.dev.json]
' 
End Event Log Message.
[aspnetcorev2.dll] Failed HRESULT returned: 0x8000ffff at c:\b\w\e37dd45d8cd1eaf4\modules\iisintegration\src\aspnetcoremodulev2\aspnetcore\handlerresolver.cpp:153 
[aspnetcorev2.dll] Failed HRESULT returned: 0x8000ffff at c:\b\w\e37dd45d8cd1eaf4\modules\iisintegration\src\aspnetcoremodulev2\aspnetcore\applicationinfo.cpp:136 
[aspnetcorev2.dll] Failed HRESULT returned: 0x8000ffff at c:\b\w\e37dd45d8cd1eaf4\modules\iisintegration\src\aspnetcoremodulev2\aspnetcore\applicationinfo.cpp:91 
[aspnetcorev2.dll] Event Log: 'Failed to start application '/LM/W3SVC/1455123678/ROOT', ErrorCode '0x8000ffff'.' 
End Event Log Message.
[aspnetcorev2.dll] ASPNET_CORE_GLOBAL_MODULE::OnGlobalStopListening
[aspnetcorev2.dll] Stopping application '/LM/W3SVC/1455123678/ROOT'
[aspnetcorev2.dll] ASPNET_CORE_GLOBAL_MODULE::Terminate

Server details using kudu

dotnet --info
.NET Core SDK (reflecting any global.json):
 Version:   2.2.100
 Commit:    51868761f2

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.14393
 OS Platform: Windows
 RID:         win10-x86
 Base Path:   D:\Program Files (x86)\dotnet\sdk\2.2.100\

Host (useful for support):
  Version: 2.2.0
  Commit:  1249f08fed

.NET Core SDKs installed:
  1.1.10 [D:\Program Files (x86)\dotnet\sdk]
  2.1.402 [D:\Program Files (x86)\dotnet\sdk]
  2.1.500 [D:\Program Files (x86)\dotnet\sdk]
  2.2.100 [D:\Program Files (x86)\dotnet\sdk]

.NET Core runtimes installed:
  Microsoft.AspNetCore.All 2.1.4 [D:\Program Files (x86)\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.1.6 [D:\Program Files (x86)\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.2.0 [D:\Program Files (x86)\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.4 [D:\Program Files (x86)\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.1.6 [D:\Program Files (x86)\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.2.0 [D:\Program Files (x86)\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 1.0.12 [D:\Program Files (x86)\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 1.1.9 [D:\Program Files (x86)\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.0.9 [D:\Program Files (x86)\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.1.4 [D:\Program Files (x86)\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.1.6 [D:\Program Files (x86)\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.2.0 [D:\Program Files (x86)\dotnet\shared\Microsoft.NETCore.App]

Program.cs

using System;
using System.Diagnostics.CodeAnalysis;
using System.IO;
using Foo.Dal;
using Microsoft.AspNetCore;
using Microsoft.AspNetCore.Hosting;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Serilog;

namespace Foo.Api
{
    [ExcludeFromCodeCoverage]
    public class Program
    {
        public static IConfiguration Configuration { get; } = new ConfigurationBuilder()
            .SetBasePath(Directory.GetCurrentDirectory())
            .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
            .AddEnvironmentVariables()
            .Build();

        public static int Main(string[] args)
        {
            Log.Logger = new LoggerConfiguration()
                .Enrich.FromLogContext()
                .ReadFrom.Configuration(Configuration)
                .WriteTo.Console()
                .CreateLogger();

            try
            {
                Log.Information("Starting web host");
                CreateWebHostBuilder(args).Build().Migrate().Run();
                return 0;
            }
            catch (Exception ex)
            {
                Log.Fatal(ex, "Host terminated unexpectedly");
                return 1;
            }
            finally
            {
                Log.CloseAndFlush();
            }
        }

        public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
            WebHost.CreateDefaultBuilder(args)
                .UseStartup<Startup>()
                .UseConfiguration(Configuration)
                .UseSerilog();


    }

    public static class MigrationExtentions
    {
        public static IWebHost Migrate(this IWebHost webhost)
        {
            using (var scope = webhost.Services.GetService<IServiceScopeFactory>().CreateScope())
            {
                using (var dbContext = scope.ServiceProvider.GetRequiredService<MyContext>())
                {
                    dbContext.Database.Migrate();
                }
            }
            return webhost;
        }
    }
}

csproj excerpt

<PropertyGroup>
    <TargetFramework>netcoreapp2.2</TargetFramework>
    <RuntimeFrameworkVersion>2.2.0</RuntimeFrameworkVersion>
    <UserSecretsId>717ec1cf-5ff6-4176-b96b-ee427f40bee5</UserSecretsId>
    <AssemblyName>Bar.Foo.Api</AssemblyName>
    <AspNetCoreHostingModel>InProcess</AspNetCoreHostingModel>
</PropertyGroup>

Directory.GetCurrentDirectory() doesn't work in InProcess hosting model in ASP.NET Core 2.2. This is bug which I have reported in Github.

Alternative solution is to write a helper class called CurrentDirectoryHelpersas follows:

internal class CurrentDirectoryHelpers
{
    internal const string AspNetCoreModuleDll = "aspnetcorev2_inprocess.dll";

    [System.Runtime.InteropServices.DllImport("kernel32.dll")]
    private static extern IntPtr GetModuleHandle(string lpModuleName);

    [System.Runtime.InteropServices.DllImport(AspNetCoreModuleDll)]
    private static extern int http_get_application_properties(ref IISConfigurationData iiConfigData);

    [System.Runtime.InteropServices.StructLayout(System.Runtime.InteropServices.LayoutKind.Sequential)]
    private struct IISConfigurationData
    {
        public IntPtr pNativeApplication;
        [System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.BStr)]
        public string pwzFullApplicationPath;
        [System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.BStr)]
        public string pwzVirtualApplicationPath;
        public bool fWindowsAuthEnabled;
        public bool fBasicAuthEnabled;
        public bool fAnonymousAuthEnable;
    }

    public static void SetCurrentDirectory()
    {
        try
        {
            // Check if physical path was provided by ANCM
            var sitePhysicalPath = Environment.GetEnvironmentVariable("ASPNETCORE_IIS_PHYSICAL_PATH");
            if (string.IsNullOrEmpty(sitePhysicalPath))
            {
                // Skip if not running ANCM InProcess
                if (GetModuleHandle(AspNetCoreModuleDll) == IntPtr.Zero)
                {
                    return;
                }

                IISConfigurationData configurationData = default(IISConfigurationData);
                if (http_get_application_properties(ref configurationData) != 0)
                {
                    return;
                }

                sitePhysicalPath = configurationData.pwzFullApplicationPath;
            }

            Environment.CurrentDirectory = sitePhysicalPath;
        }
        catch
        {
            // ignore
        }
    }
}

Then call the SetCurrentDirectory() of the CurrentDirectoryHelpers class as follows:

public class Program
{
    public static void Main(string[] args)
    {
        CurrentDirectoryHelpers.SetCurrentDirectory();

        Log.Logger = new LoggerConfiguration()
                .Enrich.FromLogContext()
                .ReadFrom.Configuration(Configuration)
                .WriteTo.Console()
                .CreateLogger();

        ...
    }
}

Now everything should work fine!