Asp .Net Configuration

 In this article I will give some tips on how one can work with configuration with ASP .Net apps. Almost all or any ASP .Net app anyway have this `Microsoft.Extensions.Configuration.IConfiguration` or simply put it as type `IConfiguration`.

There are usually one or two `json` files `appsettings.json` or or and the `appsettings.Development.json`. These contain settings for the app to use depending on the type of environment the instance is being run on. The first is for production and the later for development environment and more can de added as well.

Now let's say or `appsettings.json` is like below. Most of these config have provision for logging settings. say in production, the default might be `Information` meaning anything below that like Debug or Trace might not be logged. For development, the default might be `Debug` meaning almost all except might be `Trace` may not be logged  which deserves another article for sure.

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
...
...
}
},
  "SomeApp": {
    "Host": "192.168.a.l",
    "Email": "abc@comp.co",
"Location":
{
"First": "Gatsby"
}
  }

}}

In case we need to retrieve the Host address of our SomeApp, then in the class which is loaded by the ASP .Net server let's say `FirstService` class, the `IConfiguration` can be dependency injected and the app's settings retrieved like below.

 public class FirstService
{
public readonly IConfiguration _configuration;

public  FirstService(IConfiguration configuration)

{
    _configuration = configuration

} 

 public void RunApp()

{

 Console.WriteLine("Host Config - " + _configuration["SomeApp:Host"]);

}

}

The `_configuration["SomeApp:Host"]` should give the address value which is "192.168.a.l", in this case.
The `_configuration["SomeApp:Host:Location:First"]` should give the location value and so on.

Similarly additional configurations as json files can be added to be loaded in the `Startup` or the `Program` class as well. The fetching mechanism need not be a string key, it can be
_configuration.Get<P>() to bind the configuration to type `P` and be retrieved in a more strict type way as well.