如何从方法主体中提取配置选项并在 Dot Net Core 3.1 中使用配置 class

Question

noob here. I have followed the QuickStarts for IdentityServer 4. I am at the point of cleaning up code. I am using Net Core 3.1. My Startup.ConfigureServices has become crowded and I wanted to clean it up and put the configuration options, value(s) into a class - in the same way that IdentityServer 4 uses a class for the IdentityResources, ApiScopes, ApiResources and Client configuration options.

I have read many blog posts and I see from, https://andrewlock.net/avoiding-startup-service-injection-in-asp-net-core-3/ how to add configuration to the IoC container for custom services, but I haven't found a way to pull out the options/values for framework services such as Identity Core, or services.AddAuthentication().AddOpenIdConnect() for example.

    services.AddAuthentication(options =>
    {
      options.DefaultScheme = "Cookies";
      options.DefaultChallengeScheme = "oidc";
    })
    .AddCookie("Cookies", options =>
    {
      options.AccessDeniedPath = "/account/denied";
    })
    .AddOpenIdConnect("oidc", options =>
    {
        /***  HOW DO I PUT THE BELOW KEY/VALUES INTO A CONFIG CLASS  ***/

        options.Authority = "https://demo.identityserver.io";
        options.ClientId = "server.hybrid";
        options.ClientSecret = "secret";
        options.ResponseType = "code id_token";
 
        options.SaveTokens = true;
                    
        options.Scope.Clear();
        options.Scope.Add("openid");
                    
        options.TokenValidationParameters = new TokenValidationParameters
        {
            NameClaimType = "name", 
            RoleClaimType = "role"
        };
    });

And use that config class like this

var builder = services.AddIdentityServer()
    .AddInMemoryIdentityResources(Config.IdentityResources) <-- From the Config class
    .AddInMemoryApiScopes(Config.ApiScopes) <-- From the Config class
    .AddInMemoryClients(Config.Clients); <-- From the Config class

So in case my question wasn't clear, how can I make a Config class and pass that class into .AddOpenIdConnect(MyConfigClass) to clean up the ConfigureServices method (IoC Container?)

Is the above code the best/cleanest way to configure services in the IoC Container? Is the answer I am looking for in Andrew Lock's blog post and I just didn't understand it? I am making the assumption that I can pass a class into the.AddOpenIdConnect extension method in the same way that I can with IS4.AddInMemoryIdentityResources

Thx for the help.

Answer 1

All Microsoft services follow the same Options pattern . Firstly, you could move those lambda methods to static methods, perhaps on different classes. Which seems to be what your Config example has done. You just need to make sure your static methods have the same function signature.

For example, .AddAuthentication takes an Action<AuthenticationOptions> delegate as an argument. So any static void foo(AuthenticationOptions o) method could be passed in instead.

Or you could write services that implement IConfigureOptions<T> and register those. This is particularly useful if you need to access other services, like a database for example, in order to configure those options types.