Disable transformations in ASP.NET Core

By default when you add a web.config file to an ASP.NET Core application, the config file is transformed with the correct processPath and arguments.

	<?xml version="1.0" encoding="utf-8"?>
	<configuration>
	<!-- To customize the asp.net core module uncomment and edit the following section.
	For more info see https://go.microsoft.com/fwlink/?linkid=838655 -->
	<system.webServer>
	<handlers>
	<remove name="aspNetCore"/>
	<add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModule" resourceType="Unspecified"/>
	</handlers>
	<aspNetCore processPath="%LAUNCHER_PATH%" arguments="%LAUNCHER_ARGS%" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" />
	</system.webServer>
	</configuration>

view raw web.config hosted with ❤ by GitHub

This can be quite annoying especially if you want to apply some web config transformation magic.

Inside the documentation, I found that you can prevent the Web SDK from transforming the web.config file by setting the <IsTransformWebConfigDisabled> property in the project file:

	<PropertyGroup>
	<IsTransformWebConfigDisabled>true</IsTransformWebConfigDisabled>
	</PropertyGroup>

view raw DisableTransform.xml hosted with ❤ by GitHub

This disabled the web config transformation behavior but didn’t solve the problem that Visual Studio updated the web.config file.

A colleague sent me another (undocumented?) flag <ANCMPreConfiguredForIIS> :

	<PropertyGroup>
	<ANCMPreConfiguredForIIS>true</ANCMPreConfiguredForIIS>
	</PropertyGroup>

view raw DisableTransform2.xml hosted with ❤ by GitHub

Remark: This setting only works when you are running in IIS InProcess.