How to set Environment Name (IHostingEnvironment.EnvironmentName)?

Question

Default ASP.NET Core web project contain such lines in Startup.cs:

if (string.Equals(env.EnvironmentName, \"Development\", StringComparison.Ordi         


        

Answer 1

After RC2

So what is the way to set a different EnvironmentName?

Set the ASPNETCORE_ENVIRONMENT environmental variable.

There are many ways to set that environmental variable. These include a launchSettings.json profile and other environment-specific ways. Here are some examples.

From a console:

// PowerShell
> $env:ASPNETCORE_ENVIRONMENT="Development"

// Windows Command Line
> SET ASPNETCORE_ENVIRONMENT=Development

// Bash
> ASPNETCORE_ENVIRONMENT=Development

From an Azure Web App's App settings:

Before RC2

I can imagine that it should be set in "Commands" as a parameter for server.

That is true. In your project.json, add --ASPNET_ENV production as a parameter for the server.

"commands": {
  "web": "Microsoft.AspNet.Hosting --ASPNET_ENV production --server Microsoft.AspNet.Server.WebListener --server.urls http://localhost:5001"
}

Now when you run dnx . web from the command line, ASPNET_ENV will be production.

Relevant ASP.NET Core Hosting Source Code

The WebHostBuilder combines "ASPNETCORE_" with the WebHostDefaults.EnvironmentKey to make "ASPNETCORE_environment". It also supports the legacy keys.

WebHostDefaults.cs

namespace Microsoft.AspNetCore.Hosting
{
    public static class WebHostDefaults
    {
        public static readonly string ApplicationKey = "applicationName";
        public static readonly string StartupAssemblyKey = "startupAssembly";

        public static readonly string DetailedErrorsKey = "detailedErrors";
        public static readonly string EnvironmentKey = "environment";
        public static readonly string WebRootKey = "webroot";
        public static readonly string CaptureStartupErrorsKey = "captureStartupErrors";
        public static readonly string ServerUrlsKey = "urls";
        public static readonly string ContentRootKey = "contentRoot";
    }
}

WebHostBuilder.cs

_config = new ConfigurationBuilder()
    .AddEnvironmentVariables(prefix: "ASPNETCORE_")
    .Build();

if (string.IsNullOrEmpty(GetSetting(WebHostDefaults.EnvironmentKey)))
{
    // Try adding legacy environment keys, never remove these.
    UseSetting(WebHostDefaults.EnvironmentKey, 
        Environment.GetEnvironmentVariable("Hosting:Environment") 
        ?? Environment.GetEnvironmentVariable("ASPNET_ENV"));
}

Backward Compatibility

The environment key is set with the ASPNETCORE_ENVIRONMENT environment variable. ASPNET_ENV and Hosting:Environment are still supported, but generate a deprecated message warning.

https://docs.asp.net/en/latest/migration/rc1-to-rtm.html

Default Value

The default value is "Production" and is set here.

Answer 2

launchsettings.json

At Properties > launchsettings.json

Just like this:

    {
  "iisSettings": {
    "windowsAuthentication": false,
    "anonymousAuthentication": true,
    "iisExpress": {
      "applicationUrl": "http://localhost:1032/",
      "sslPort": 0
    }
  },
  "profiles": {
    "IIS Express": {
      "commandName": "IISExpress",
      "launchBrowser": true,
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Production"
      }
    },
    "WebAppNetCore": {
      "commandName": "Project",
      "launchBrowser": true,
      "launchUrl": "http://localhost:5000",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    },
    "web": {
      "commandName": "web",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    }
  }
}

Answer 3

I had same problem. To to be independet to enviroment variable and web.config, I created a .json file as (I called it envsettings.json):

{
  // Possible string values reported below.
  // - Production
  // - Staging
  // - Development
  "ASPNETCORE_ENVIRONMENT": "Staging"
}

Then in Program.cs I added:

public class Program
{
    public static void Main(string[] args)
    {
        var currentDirectoryPath = Directory.GetCurrentDirectory();
        var envSettingsPath = Path.Combine(currentDirectoryPath, "envsettings.json");
        var envSettings = JObject.Parse(File.ReadAllText(envSettingsPath));
        var enviromentValue = envSettings["ASPNETCORE_ENVIRONMENT"].ToString();

        var webHostBuilder = new WebHostBuilder()
            .UseKestrel()
            .CaptureStartupErrors(true)
            .UseSetting("detailedErrors", "true")
            .UseContentRoot(currentDirectoryPath)
            .UseIISIntegration()
            .UseStartup<Startup>();

        // If none is set it use Operative System hosting enviroment
        if (!string.IsNullOrWhiteSpace(enviromentValue)) 
        {
            webHostBuilder.UseEnvironment(enviromentValue);
        }

        var host = webHostBuilder.Build();

        host.Run();
    }
}

Answer 4

1. On Azure just set ASPNET_ENV environment variable on web app configuration page.

2. With your own IIS or other hosting providers - modify web.config to include arguments for "web" command:

   <configuration>
    <system.webServer>
     <handlers>
       <add name="httpplatformhandler" path="*" verb="*" modules="httpPlatformHandler" resourceType="Unspecified" />
     </handlers>
     <httpPlatform processPath="..\approot\web.cmd" arguments="--ASPNET_ENV Development" stdoutLogEnabled="false" stdoutLogFile="..\logs\stdout.log" startupTimeLimit="3600"></httpPlatform>
    </system.webServer>
   </configuration>
   

3. During development (if you can modify source code), you can also create file named Microsoft.AspNet.Hosting.json in a root of your project and set the ASPNET_ENV variable.

   { "ASPNET_ENV": "Test" }

Answer 5

In ASP.NET Core RC2 the variable name is has been changed to ASPNETCORE_ENVIRONMENT

e.g. In Windows you can execute this command on the staging server (with admin rights)

SETX ASPNETCORE_ENVIRONMENT "Staging" /M

This only has be be executed once and after that, the server will always be considered as the staging server.

When you do a dotnet run in the command prompt on that server you will see Hosting environment: Staging