ASP.NET 5 JSON与Azure Web App

Question

I am trying to use custom configuration for a web app that I intent to host on Azure. The configuration should be overridable by Environment variables so that I can change it on Azure portal.

I tried with following code but it does not work - details below

   public Startup(IHostingEnvironment env, IApplicationEnvironment appEnv)
   {
      var builder = new ConfigurationBuilder()
                        .AddJsonFile("config.json", optional:true)
                        .AddEnvironmentVariables();
      Configuration = builder.Build();            
   }

   public IConfigurationRoot Configuration { get; set; }

   public void ConfigureServices(IServiceCollection services)
   {
      services.AddOptions(); 
      services.Configure<AppSettings>(Configuration);
   }

In the controller,

public class HomeController : Controller
{
    private IOptions<AppSettings> Configuration;

    public HomeController(IOptions<AppSettings> configuration)
    {
        Configuration = configuration;
    }

    public async Task<IActionResult> Index()
    {
          string location = Configuration.Value.Location;   
          ...
    }

The default config.json file looks like,

{
  "AppSettings": {
    "Location" : "Singapore"
  }
}

On Azure Portal, under app settings I have assigned value to AppSettings:Location to US and I am expecting US value in the controller.

Locally, in ConfigureServices I can see the value as Singapore but in the controller action Index it is null.

Am I missing something here?

Answer 1

When you are reading the config.json, you need to load the section that you want to read, you need to update your code as follow:

public void ConfigureServices(IServiceCollection services)
{
    services.AddOptions();
    services.Configure<AppSettings>(Configuration.GetSection("AppSettings"));
}