Starting ASP.NET Core 3.1 Site in IIS [duplicate]

Answer 1

It seems that you missed to install Asp.net Core web hosting bundle. Asp.net core is not supported by IIS by default even you can run it in Visual studio IIS express. Besides, IIS won't register AspNetCore handler even when you install asp.net core web hosting bundle.

So please ensure you have registered the handler and asp.net core module in web.config

<configuration>
  <location path="." inheritInChildApplications="false">
    <system.webServer>
      <handlers>
        <add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModule" resourceType="Unspecified" />
      </handlers>
      <aspNetCore processPath="dotnet" arguments=".\MyWebApp.dll" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" hostingModel="inprocess" />
    </system.webServer>
  </location>

Of course, you can publish your application with VS web deployment tool. It will register these configuration when you publish the project.

https://docs.microsoft.com/en-us/aspnet/core/host-and-deploy/iis/?view=aspnetcore-3.1

Answer 2

Make sure you've done the following:

• Installed latest Core hosting bundle. If not, go here and look for "Hosting Bundle" https://dotnet.microsoft.com/download/dotnet-core/3.1 (you should go there on regular basis, a new version about every month, latest is 3.1.7 when writing this)
• In app pool, make sure .NET framework is not selected

When publish, use

Deployment Mode = Framework-Dependent
Target Runtime = win-x64

In your publish profile (you find this file in project folder /Properties/PublishProfiles/YourProfileName.pubxml) after saving the profile, you'll need

<EnvironmentName>Production</EnvironmentName>
<AspNetCoreHostingModel>InProcess</AspNetCoreHostingModel>

InProcess is the fastest option when using IIS. When running publish, this will end up in your generated web.config like this

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <system.webServer>
    <handlers>
      <add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModuleV2" resourceType="Unspecified" />
    </handlers>
    <aspNetCore processPath=".\YourWebApp.exe" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" hostingModel="InProcess">
      <environmentVariables>
        <environmentVariable name="ASPNETCORE_ENVIRONMENT" value="Production" />
      </environmentVariables>
    </aspNetCore>
  </system.webServer>
</configuration>

When deploying to a staging server, create a new publish profile, and use

<EnvironmentName>Staging</EnvironmentName>
<AspNetCoreHostingModel>InProcess</AspNetCoreHostingModel>

When you get answer from https://localhost:5001/ you are running Kestrel, not IIS