Btukfyl

First off:
The assembly name and namespace of Microsoft.Framework.ConfigurationModel has changed to Microsoft.Framework.Configuration. So you should use:
e.g.

"Microsoft.Framework.Configuration.Json": "1.0.0-beta7"

as a dependency in project.json. Use beta5 or 6 if you don't have 7 installed.
Then you can do something like this in Startup.cs.

public IConfiguration Configuration { get; set; }



public Startup(IHostingEnvironment env, IApplicationEnvironment appEnv)

{

     var configurationBuilder = new ConfigurationBuilder(appEnv.ApplicationBasePath)

        .AddJsonFile("config.json")

        .AddEnvironmentVariables();

     Configuration = configurationBuilder.Build();

}

If you then want to retrieve a variable from the config.json you can get it right away using:

public void Configure(IApplicationBuilder app)

    {

        // Add .Value to get the token string

        var token = Configuration.GetSection("AppSettings:token");

        app.Run(async (context) =>

        {

            await context.Response.WriteAsync("This is a token with key (" + token.Key + ") " + token.Value);

        });

    }

or you can create a class called AppSettings like this:

public class AppSettings

{

    public string token { get; set; }

}

and configure the services like this:

public void ConfigureServices(IServiceCollection services)

{       

    services.AddMvc();



    services.Configure<MvcOptions>(options =>

    {

        //mvc options

    });



    services.Configure<AppSettings>(Configuration.GetSection("AppSettings"));

}

and then access it through e.g. a controller like this:

public class HomeController : Controller

{

    private string _token;



    public HomeController(IOptions<AppSettings> settings)

    {

        _token = settings.Options.token;

    }

}

For .NET Core 2.0, things have changed a little bit. The startup constructor takes a Configuration object as a parameter, So using the ConfigurationBuilder is not required. Here is mine:

public Startup(IConfiguration configuration)

{

    Configuration = configuration;

}



public IConfiguration Configuration { get; }



// This method gets called by the runtime. Use this method to add services to the container.

public void ConfigureServices(IServiceCollection services)

{

    services.Configure<StorageOptions>(Configuration.GetSection("AzureStorageConfig"));

}

My POCO is the StorageOptions object mentioned at the top:

namespace Brazzers.Models

{

    public class StorageOptions

    {

        public String StorageConnectionString { get; set; }

        public String AccountName { get; set; }

        public String AccountKey { get; set; }

        public String DefaultEndpointsProtocol { get; set; }

        public String EndpointSuffix { get; set; }



        public StorageOptions() { }

    }

}

And the configuration is actually a subsection of my appsettings.json file, named AzureStorageConfig:

{

  "ConnectionStrings": {

    "DefaultConnection": "Server=(localdb)\mssqllocaldb;",

    "StorageConnectionString": "DefaultEndpointsProtocol=https;AccountName=brazzerswebapp;AccountKey=Cng4Afwlk242-23=-_d2ksa69*2xM0jLUUxoAw==;EndpointSuffix=core.windows.net"

  },

  "Logging": {

    "IncludeScopes": false,

    "LogLevel": {

      "Default": "Warning"

    }

  },



  "AzureStorageConfig": {

    "AccountName": "brazzerswebapp",

    "AccountKey": "Cng4Afwlk242-23=-_d2ksa69*2xM0jLUUxoAw==",

    "DefaultEndpointsProtocol": "https",

    "EndpointSuffix": "core.windows.net",

    "StorageConnectionString": "DefaultEndpointsProtocol=https;AccountName=brazzerswebapp;AccountKey=Cng4Afwlk242-23=-_d2ksa69*2xM0jLUUxoAw==;EndpointSuffix=core.windows.net"

  }

}

The only thing I'll add is that, since the constructor has changed, I haven't tested whether something extra needs to be done for it to load appsettings.<environmentname>.json as opposed to appsettings.json.

If you just want to get the value of the token then use

Configuration["AppSettings:token"]

For .NET Core 2.0, you can simply:

Declare your key/value pairs in appsettings.json:

{

  "MyKey": "MyValue

}

Inject the configuration service in startup.cs, and get the value using the service

using Microsoft.Extensions.Configuration;



public class Startup

{

    public void Configure(IConfiguration configuration,

                          ... other injected services

                          )

    {

        app.Run(async (context) =>

        {

            string myValue = configuration["MyKey"];

            await context.Response.WriteAsync(myValue);

        });

Following works for Console Apps;

1- install following nuget packages (.csproj);

<ItemGroup>

    <PackageReference Include="Microsoft.Extensions.Configuration" Version="2.2.0-preview2-35157" />

    <PackageReference Include="Microsoft.Extensions.Configuration.FileExtensions" Version="2.2.0-preview2-35157" />

    <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="2.2.0-preview2-35157" />

  </ItemGroup>

2- Create appsettings.json at root level. Right click on it and "Copy to Output Directory" as "Copy if newer".

3- Sample config file:

{

  "AppConfig": {

    "FilePath": "C:\temp\logs\output.txt"

  }

}

4- Program.cs

configurationSection.Key and configurationSection.Value will have config properties.

static void Main(string args)

{

    try

    {



        IConfigurationBuilder builder = new ConfigurationBuilder()

            .SetBasePath(Directory.GetCurrentDirectory())

            .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true);



        IConfigurationRoot configuration = builder.Build();

        // configurationSection.Key => FilePath

        // configurationSection.Value => C:\temp\logs\output.txt

        IConfigurationSection configurationSection = configuration.GetSection("AppConfig").GetSection("FilePath");  



    }

    catch (Exception e)

    {

        Console.WriteLine(e);

    }

}

Just to complement the Yuval Itzchakov answer.

You can load configuration without builder function, you can just inject it.

public IConfiguration Configuration { get; set; }



public Startup(IConfiguration configuration)

{

   Configuration = configuration;

}

They just keep changing things – having just updated VS and had the whole project bomb, on the road to recovery and the new way looks like this:

public Startup(IHostingEnvironment env)

{

    var builder = new ConfigurationBuilder()

        .SetBasePath(env.ContentRootPath)

        .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)

        .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true);



    if (env.IsDevelopment())

    {

        // For more details on using the user secret store see http://go.microsoft.com/fwlink/?LinkID=532709

        builder.AddUserSecrets();

    }



    builder.AddEnvironmentVariables();

    Configuration = builder.Build();

}

I kept missing this line!

.SetBasePath(env.ContentRootPath)

So I doubt this is good practice but it's working locally, I'll update this if it fails when I publish/deploy (to an IIS web service).

Step 1.) Add this assembly to the top of your class (in my case, controller class):

using Microsoft.Extensions.Configuration;

Step 2.) Add this or something like it:

var config = new ConfigurationBuilder()
.SetBasePath(Directory.GetCurrentDirectory())
.AddJsonFile("appsettings.json").Build();

Step 3.) Call your key's value by doing this (returns string):

config["NameOfYourKey"]

In addition to existing answers I'd like to mention that sometimes it might be useful to have extension methods for IConfiguration for simplicity's sake.

I keep JWT config in appsettings.json so my extension methods class looks as follows:

public static class ConfigurationExtensions

{

    public static string GetIssuerSigningKey(this IConfiguration configuration)

    {

        string result = configuration.GetValue<string>("Authentication:JwtBearer:SecurityKey");

        return result;

    }



    public static string GetValidIssuer(this IConfiguration configuration)

    {

        string result = configuration.GetValue<string>("Authentication:JwtBearer:Issuer");

        return result;

    }



    public static string GetValidAudience(this IConfiguration configuration)

    {

        string result = configuration.GetValue<string>("Authentication:JwtBearer:Audience");

        return result;

    }



    public static string GetDefaultPolicy(this IConfiguration configuration)

    {

        string result = configuration.GetValue<string>("Policies:Default");

        return result;

    }



    public static SymmetricSecurityKey GetSymmetricSecurityKey(this IConfiguration configuration)

    {

        var issuerSigningKey = configuration.GetIssuerSigningKey();

        var data = Encoding.UTF8.GetBytes(issuerSigningKey);

        var result = new SymmetricSecurityKey(data);

        return result;

    }



    public static string GetCorsOrigins(this IConfiguration configuration)

    {

        string result =

            configuration.GetValue<string>("App:CorsOrigins")

            .Split(",", StringSplitOptions.RemoveEmptyEntries)

            .ToArray();



        return result;

    }

}

It saves you a lot of lines and you just write clean and minimal code:

...

x.TokenValidationParameters = new TokenValidationParameters()

{

    ValidateIssuerSigningKey = true,

    ValidateLifetime = true,

    IssuerSigningKey = _configuration.GetSymmetricSecurityKey(),

    ValidAudience = _configuration.GetValidAudience(),

    ValidIssuer = _configuration.GetValidIssuer()

};

It's also possible to register IConfiguration instance as singleton and inject it wherever you need - I use Autofac container here's how you do it:

var appConfiguration = AppConfigurations.Get(WebContentDirectoryFinder.CalculateContentRootFolder());

builder.Register(c => appConfiguration).As<IConfigurationRoot>().SingleInstance();

You can do the same with MS Dependency Injection:

services.AddSingleton<IConfigurationRoot>(appConfiguration);

Was this "cheating"? I just made my Configuration in the Startup class static, and then I can access it from anywhere else:

public class Startup

{

    // This method gets called by the runtime. Use this method to add services to the container.

    // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940

    public Startup(IHostingEnvironment env)

    {

        var builder = new ConfigurationBuilder()

            .SetBasePath(env.ContentRootPath)

            .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)

            .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)

            .AddEnvironmentVariables();



        Configuration = builder.Build();

    }



    public static IConfiguration Configuration { get; set; }