Like most things here this is a simple write up so I remember that something exists when I want it again in the future.

For various reasons I’ve been trying to publish a dot net web application locally to run under IIS, but not wanting to rely on having to set the ASPNETCORE_ENVIRONMENT as an environment variable due to other applications having slightly different appsettings and me not truly being the owner of the deployment environment.

Luckily there is a way to achieve this. When a web application runs under IIS it still uses a web.config, and that web.config can contain a section such as this:

<aspNetCore processPath="dotnet" arguments=".\MyApp.dll" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" hostingModel="inprocess">
<environmentVariables>
    <environmentVariable name="ASPNETCORE_ENVIRONMENT" value="test" />
</environmentVariables>
</aspNetCore>

This can be cumbersome to manually keep updated (and if you were doing that you could just manually update the appsettings anyway). So along comes the publish profiles.

I only want a quick and dirty publish to local file system for these sites so I can copy and paste (yes, horrible I know):

<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
    <PropertyGroup>
        <WebPublishMethod>FileSystem</WebPublishMethod>
        <ExcludeApp_Data>False</ExcludeApp_Data>                       
        <SkipExtraFilesOnServer>True</SkipExtraFilesOnServer>
        <MSDeployPublishMethod>InProc</MSDeployPublishMethod>        
        <SelfContained>false</SelfContained>
        <EnvironmentName>test</EnvironmentName>
        <_IsPortable>false</_IsPortable>
        <_SavePWD>False</_SavePWD>
    </PropertyGroup>
</Project>

The key here being the EnvironmentName which will control the environment variables specific in the web.config.

Update: A slightly alternative way to achieve this is to use the build configuration instead, and set the EnvironmentName in the .csproj file like so:

<PropertyGroup Condition="'$(Configuration)'=='Test'">
    <EnvironmentName>test</EnvironmentName>
</PropertyGroup>