Automatically set appsettings.json for dev and release environments in asp.net core?

Question

I've defined some values in my appsettings.json for things like database connection strings, webapi locations and the like which are different for development, staging and live environments.

Is there a way to have multiple appsettings.json files (like appsettings.live.json, etc, etc) and have the asp.net app just 'know' which one to use based on the build configuration it's running?

Answer 1

I have added screenshots of a working environment, because it cost me several hours of R&D.

1. First, add a key to your launch.json file.

   See the below screenshot, I have added Development as my environment.

   

2. Then, in your project, create a new appsettings.{environment}.json file that includes the name of the environment.

   In the following screenshot, look for two different files with the names:

   • appsettings.Development.Json
   • appSetting.json

   
   

3. And finally, configure it to your StartUp class like this:

   public Startup(IHostingEnvironment env)
   {
       var builder = new ConfigurationBuilder()
           .SetBasePath(env.ContentRootPath)
           .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
           .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
           .AddEnvironmentVariables();
   
       Configuration = builder.Build();
   }
   

4. And at last, you can run it from the command line like this:

   dotnet run --environment "Development"
   

   where "Development" is the name of my environment.