How to use appsettings.Development.json variables in code

Question

I have an appsettings.json and appsettings.Development.json. I need to assign the SmtpServer name depending on the environment.

The config file in appsettings.json is:

{ 
  "EmailConfiguration": {
   "SmtpServer": "mail.MYDOMAIN.com"
  }
}

And in appsettings.Development.json is:

{ 
  "EmailConfiguration": {
    "SmtpServer": "mail.MYLOCAL.com"
  }
}

When I assign the configuration in Startup ConfigureServices() like such:

var emailconfig = Configuration.GetSection("EmailConfiguration").Get<EmailConfiguration>();
services.AddSingleton<IEmailConfiguration>(emailconfig);

It always uses appsettings.json ('mail.MYDOMAIN.com') and NOT appsettings.Development.json.

How do I modify this code to use the correct environment settings?

In VS I'm using the Debug configuration and within that I have: Environment variables Name: ASPNETCORE_ENVIRONMENT Value: Development. — P-Finny
you sould read the doc regarding configuration I think : docs.microsoft.com/en-us/aspnet/core/fundamentals/configuration/… — agua from mars
Looks like P-Finny did everything under that doc page. @P-Finny Have you tried killing iisexpress? — Dan Schnau
@DanSchnau I did one better and restarted my machine to make sure IISExpress was cleared out. I've put in a variable in the Startup method and confirmed my environment is 'Development'. After reading the documentation again on setup I am not seeing anything that specifically says returning a Configuration.GetSection() will get the environment specific variable. Do you know if that should happen? Or do I need to call a more environment specific method? — P-Finny

P-Finny P-Finny · Accepted Answer · 2018-01-02T19:59:23

The answer is that all I needed was the environment variables in the 2 different appsettings files. My problem was a missing closing bracket in one of my configuration settings which meant that the appsettings.Development.json would not replace appsettings.json variables since they didn't match. Oops.....

How to use appsettings.Development.json variables in code

1 Answers