Set web.config transform in Asp.NET Core - asp.net-core

Question

I've just came across with problem of web.config transformation in asp.net core.
There are two files: base web.config and web.prod-zone-a.config. My aim is to use transformation inside web.prod-zone-a.config when publishing my project.
I have the following "prod-zone-a" configuration settings in .csproj:
<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'prod-zone-a|AnyCPU' ">
<IntermediateOutputPath>obj\Debug\netcoreapp1.1</IntermediateOutputPath>
<DebugSymbols>true</DebugSymbols>
<Optimize>false</Optimize>
<DefineConstants>TRACE;DEBUG;NETCOREAPP1_1</DefineConstants>
<Configuration>prod-zone-a</Configuration>
</PropertyGroup>
web.prod-zone-a.config looks like:
<system.webServer>
<handlers>
<add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModule" resourceType="Unspecified" />
</handlers>
<aspNetCore>
<environmentVariables xdt:Transform="Replace">
<environmentVariable name="ASPNETCORE_ENVIRONMENT" value="prod-zone-a" />
</environmentVariables>
</aspNetCore>
</system.webServer>
I tried to run publish by two commands:
dotnet msbuild /t:Publish /p:OutputPath=c:\delivery /p:Configuration=prod-zone-a
and
dotnet publish --configuration prod-zone-a --output c:\delivery
But no transformation applies to web.config on output - just the default value.
Do I miss something in configuration or command executing?

Answer 1

This worked for me:
Add web.release.config file to the project root.
In Visual Studio 2017, Publish using Web Deploy (make sure it is set to Release). Settings will automatically be picked up.
Sample transformation:
<?xml version="1.0"?>
<configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
<system.webServer>
<aspNetCore>
<environmentVariables>
<environmentVariable name="ASPNETCORE_ENVIRONMENT" value="PRODUCTION" xdt:Locator="Match(name)" xdt:Transform="SetAttributes" />
</environmentVariables>
</aspNetCore>
</system.webServer>
</configuration>
Update: If you want to remove web.config.release file and others on publish, simply edit your .csproj file and add something like this:
<ItemGroup>
<Content Remove="appsettings.Development.json" />
<Content Remove="web.release.config" />
</ItemGroup>
<ItemGroup>
<None Include="appsettings.Development.json" />
<None Include="web.release.config" />
</ItemGroup>

Answer 2

There is a well-documented tool on github for xdt-transformations.
Also it doesn't depend on command, both of dotnet publish and dotnet msbuild works fine

Answer 3

With the latest version of dotnet cli (2.1.400 or greater), you can just set this msbuild property $(EnvironmentName) and publish tooling will take care of adding ASPNETCORE_ENVIRONMENT environmentVariable to the web.config with the specified environment name.
Also, XDT support is available starting 2.2.100-preview1.
Sample: https://github.com/vijayrkn/webconfigtransform/blob/master/README.md

Answer 4

IIS Web Deploy ASP.NET Core (2.1) in Visual Studio 2017 (VS2017)
First do this: (ref:https://github.com/nil4/dotnet-transform-xdt#-use-with-msbuildcsproj-tooling)
Install package - dotnet add package DotNet.Xdt --version 2.1.0
Modify .csproj - add package - refer github
Modify .csproj - add transform code (ApplyXdtConfigTransform) at the end - refer github
Add web.DEV_Server.config transfor file by right-clicking on DEV_Server.pubxml
Added following to web.DEV_Server.config
<environmentVariable xdt:Locator="Match(name)" name="ASPNETCORE_ENVIRONMENT" value="Development" xdt:Transform="SetAttributes" />
Modify DEV_Server.pubxml to modify following setting value.
<LastUsedBuildConfiguration>DEV_Server</LastUsedBuildConfiguration>
Validate Connection & Publish
Deploy still uploads other config files, not sure how to stop that.

Answer 5

Following on from user1820686's answer above:
The github page misses out some of the steps required to add this for MSBuild/csproj tooling:
You need to open a command prompt in your project directory and run
dotnet add myProj.csproj package Microsoft.DotNet.Xdt.Tools --version 2.0.0
Then you need to open the csproj file and add
<ItemGroup>
<DotNetCliToolReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Tools" Version="2.0.0" />
<DotNetCliToolReference Include="Microsoft.Dotnet.Xdt.Tools" Version="2.0.0" />
<!-- ... other package references ... -->
</ItemGroup>

Answer 6

may be i don't clear question. For mine case web.config override all settings in web.Release.config file.
Fix for me, i just add reference for transformation xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform" to configuration file.
so, .config file should start:
<?xml version="1.0" encoding="utf-8"?>
<configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
After some time, the best solutions is using dotnet-transform-xdt tool

Answer 7

This is now supported by dotnet publish from SDK version 2.2 with a whole bunch of options.
https://learn.microsoft.com/en-us/aspnet/core/host-and-deploy/iis/transform-webconfig?view=aspnetcore-2.2
I think in the example from the question, it would then work when published as
dotnet publish --configuration prod-zone-a

Answer 8

This worked for me with the 1. & 2. above:
<?xml version="1.0"?>
<configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
<location>
<system.webServer>
<httpErrors existingResponse="PassThrough"
xdt:Locator="Match(existingResponse)"
xdt:Transform="InsertIfMissing" />
</system.webServer>
</location>
</configuration>