How to set ASPNETCORE_ENVIRONMENT during publishing?

Question

I have several WebDeploy publish profiles that deploy my .NET Core web project to various places (Dev, QA, Stage on IIS). For the application to know where it's running, I need to set the ASPNETCORE_ENVIRONMENT environment variable.

Is it possible to set the ASPNETCORE_ENVIRONMENT environment variable as a part of publishing the application?

P.S. This question doesn't solve anything for me because it shows how to achieve it manually. I would like it to be automatic as a part of deploy a publish profile.

Answer 1

I accidentally found a simple answer to the OP's question.

If an environment variable named environmentName is set when you called dotnet publish it will incorporate it into your web.config.

Azure App Service - What modified my web.config?

Answer 2

After a long search, reading and experimenting, i solved by simply adding the enviroment variable ASPNETCORE_ENVIRONMENT in my .pubxml

<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    <ASPNETCORE_ENVIRONMENT>Test</ASPNETCORE_ENVIRONMENT>
  </PropertyGroup>
  <PropertyGroup>
    <WebPublishMethod>MSDeploy</WebPublishMethod>
    <LastUsedBuildConfiguration>Release</LastUsedBuildConfiguration>
    <LastUsedPlatform>Any CPU</LastUsedPlatform>
    .....
  </PropertyGroup>
</Project>

I use it to select my react app's build environment, on publish, my .csproj looks like:

  <Target Name="PublishRunWebpack" AfterTargets="ComputeFilesToPublish">
    <Exec WorkingDirectory="$(SpaRoot)" Command="npm install" />
    <Exec WorkingDirectory="$(SpaRoot)" Command="npm run build:$(ASPNETCORE_ENVIRONMENT.ToLower())" />
    ...
  </Target>

Finally my react app's package.json:

"scripts": {
    "start": "env-cmd -f .env.development react-scripts start",
    "build:production": "env-cmd -f .env.production react-scripts build",
    "build:staging": "env-cmd -f .env.staging react-scripts build",
    "build:test": "env-cmd -f .env.test react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject",
    "mock:api": "json-server --watch db.json --port 4000"
  },

I intentionally removed "build": "react-scripts build" line, so environment is always supplied.

EDIT:

I also added PropertyGroup for setting EnvironmentName in .csproj file, so on publishing, my web.config will set the ASPNETCORE_ENVIRONMENT as environment variable, as defined in my .pubxml, dynamically:

  <Target Name="PublishRunWebpack" AfterTargets="ComputeFilesToPublish">
    <Exec WorkingDirectory="$(SpaRoot)" Command="npm install" />
    <Exec WorkingDirectory="$(SpaRoot)" Command="npm run build:$(ASPNETCORE_ENVIRONMENT.ToLower())" />
    <PropertyGroup>
      <EnvironmentName>$(ASPNETCORE_ENVIRONMENT)</EnvironmentName>
    </PropertyGroup>
  </Target>

Answer 3

From https://learn.microsoft.com/en-us/aspnet/core/fundamentals/environments?view=aspnetcore-3.1#set-the-environment

For Windows IIS deployments: Include the property in the publish profile (.pubxml) or project file. This approach sets the environment in web.config when the project is published.

<PropertyGroup>
  <EnvironmentName>Development</EnvironmentName>
</PropertyGroup>

Answer 4

You can Just Update your webconfig file with below text in section.

<configuration>
  <system.webServer>
    <aspNetCore .....>
      <environmentVariables>
        <environmentVariable name="ASPNETCORE_ENVIRONMENT" value="Development" />
      </environmentVariables>
    </aspNetCore>
  </system.webServer>
</configuration>

Or you can follow below step after hosting your application in IIS.

Step 1 : Click on configuration editor as shown in below image

Step 2 :

now select system.webserver/asp.netcore and in other dropdown select applicationHost.config shown in below image.

Step 3 :

Now select enviromentVariable and enter value.

I hope it may help you.

Answer 5

For publishing the web.config with specific environment, you could try Transform web.config.

For your requirement, you could try Profile.

1. Create multiple web.{profile}.config with different ASPNETCORE_ENVIRONMENT environment variable.

   eg.web.Dev.config

   <?xml version="1.0" encoding="utf-8"?>
   <configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
   <location>
       <system.webServer>
       <aspNetCore>
           <environmentVariables xdt:Transform="InsertIfMissing">
           <environmentVariable name="ASPNETCORE_ENVIRONMENT"
                               value="Dev"
                               xdt:Locator="Match(name)"
                               xdt:Transform="InsertIfMissing" />
           </environmentVariables>
       </aspNetCore>
       </system.webServer>
   </location>
   </configuration>
   

   eg. web.Release.config

   <?xml version="1.0" encoding="utf-8"?>
   <configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
   <location>
       <system.webServer>
       <aspNetCore>
           <environmentVariables xdt:Transform="InsertIfMissing">
           <environmentVariable name="ASPNETCORE_ENVIRONMENT"
                       value="Release"
                       xdt:Locator="Match(name)"
                       xdt:Transform="InsertIfMissing" />
           </environmentVariables>
       </aspNetCore>
       </system.webServer>
   </location>
   </configuration>
   

2. Create your project profile with the specific name like Dev and Release, you could create the web.{profile}.config with your existing profile name.

3. After publishing, it will copy the specific content from web.{profile}.config to the web.config

4. Currently, it will exsit web.config, web.Dev.config and web.Release.config in your publihshed folder, if you prefer only web.config, change your Project.csproj like below to exclude the unwantted files.

   <Project Sdk="Microsoft.NET.Sdk.Web">
   
   <PropertyGroup>
       <TargetFramework>netcoreapp2.2</TargetFramework>
       <AspNetCoreHostingModel>InProcess</AspNetCoreHostingModel>
       <Configurations>Debug;Release;Dev</Configurations>
   </PropertyGroup>
   
   <ItemGroup>
       <PackageReference Include="Microsoft.AspNetCore.App" />
       <PackageReference Include="Microsoft.AspNetCore.Razor.Design" Version="2.2.0" PrivateAssets="All" />
   </ItemGroup>
   <ItemGroup>
       <Content Update="web.Dev.config" CopyToPublishDirectory="Never" />
       <Content Update="web.Release.config" CopyToPublishDirectory="Never" />
   </ItemGroup>
   </Project>