I am learning ASP.NET core and struggling trying to inject some ILogger instances required as parameters within a factory method used within my AddJsonProtocol of the AddSignalR method. See code below.
The JsonConvertersFactory factory method creates the JsonConverters for serialization/deserialization in signalR. It is used within the .AddJsonProtocol anonymous method when adding SignalR service.
public void ConfigureServices(IServiceCollection services)
{
services.AddRazorPages();
services.AddServerSideBlazor();
services.AddHostedService<MqttKafkaBridge>();
services.AddHostedService<ConsumerService>();
services.AddLogging();
// how can I retrieve ILogger<MotionDetection>, ILogger<MotionInfo>, ILogger<JsonVisitor>?
services.AddSignalR(o => o.EnableDetailedErrors = true)
.AddJsonProtocol(options =>
{
options.PayloadSerializerOptions = JsonConvertersFactory.CreateDefaultJsonConverters(LoggerMotionDetection, LoggerMotionInfo, LoggerJsonVisitor);
});
services.AddCustomConfiguration(services);
}
I could build a temporary service provider and add logger dependencies so that the SignalR Json protocol could be configued. However I am not sure if this is considered an anti-pattern....
var sp = services.BuildServiceProvider();
var loggerMD = sp.GetService<ILogger<MotionDetection>>();
var loggerMI = sp.GetService<ILogger<MotionInfo>>();
var loggerJV = sp.GetService<ILogger<JsonVisitor>>();
When I use BuildServiceProvider I receive the following warning message:
Startup.cs(53,22): warning ASP0000: Calling 'BuildServiceProvider' from application code results in an additional copy of singleton services being created. Consider alternatives such as dependency injecting services as parameters to 'Configure'.
Is it possible to add a service in Configure method, i.e. add the SignalR service in Configure when ILogger instances can be resolved?
OR
Is it possible to inject the SignalRService in Configure method and update it's Json protocol configuration?
Update
Tried injecting ISignalRServerBuilder in Configurebut receive an exception that could not find an ISignalRServerBuilder instance in container registry (Autofac).
Any ideas?
public void Configure(IApplicationBuilder app, ISignalRServerBuilder builder, IWebHostEnvironment env)
{
// this tries to build the options from the service container but
// the builder is null
builder.AddJsonProtocol(op =>
{
var lMD = app.ApplicationServices.GetService<ILogger<MotionDetectionConverter>>();
var lMI = app.ApplicationServices.GetService<ILogger<MotionInfoConverter>>();
var lJV = app.ApplicationServices.GetService<ILogger<JsonVisitor>>();
op.PayloadSerializerOptions = JsonConvertersFactory.CreateDefaultJsonConverters(lMD, lMI, lJV);
});
...
}
Related
I'm trying to access one of my services from within the Configure call within Startup.cs in aspnet core. I'm doing the following however I get the following error "No service for type 'UserService' has been registered." Now I know it is registered because I can use it in a controller so I'm just doing something wrong when it comes to using it here. Please can someone point me in the right direction. I'm happy with taking a different approach to setting up Tus if there's a better way of achieving what I want.
var userService = app.ApplicationServices.GetRequiredService<UserService>();
userService.UpdateProfileImage(file.Id);
The below is where I'm wanting to use
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
... Other stuff here...
app.InitializeSimpleInjector(container, Configuration);
container.Verify();
app.UseTus(httpContext =>
{
var restaurantEndpoint = "/restaurant/images";
var userEndpoint = "/account/images";
var endPoint = "/blank/images";
if (httpContext.Request.Path.StartsWithSegments(new PathString(restaurantEndpoint)))
{
endPoint = restaurantEndpoint;
}
if (httpContext.Request.Path.StartsWithSegments(new PathString(userEndpoint)))
{
endPoint = userEndpoint;
}
return new BranchTusConfiguration
{
Store = new TusDiskStore(#"C:\tusfiles\"),
UrlPath = endPoint,
Events = new Events
{
OnBeforeCreateAsync = ctx =>
{
return Task.CompletedTask;
},
OnCreateCompleteAsync = ctx =>
{
return Task.CompletedTask;
},
OnFileCompleteAsync = async ctx =>
{
var file = await ( (ITusReadableStore)ctx.Store ).GetFileAsync(ctx.FileId, ctx.CancellationToken);
var userService = app.ApplicationServices.GetRequiredService<UserService>();
userService.UpdateProfileImage(file.Id);
}
}
};
});
... More stuff here...
};
My end goal is to move this to an IApplicationBuilder extension to clean up my startup.cs but that shouldn't affect anything if it's working from within startup.cs
Edit: Add to show the registration of the userService. There is a whole lot of other stuff being registered and cross wired in the InitializeSimpleInjector method which I've left out. can add it all if need be..
public static void InitializeSimpleInjector(this IApplicationBuilder app, Container container, IConfigurationRoot configuration)
{
// Add application presentation components:
container.RegisterMvcControllers(app);
container.RegisterMvcViewComponents(app);
container.Register<UserService>(Lifestyle.Scoped);
container.CrossWire<IServiceProvider>(app);
container.Register<IServiceCollection, ServiceCollection>(Lifestyle.Scoped);
}
Please read the Simple Injector integration page for ASP.NET Core very closely, as Simple Injector integrates very differently with ASP.NET Core as Microsoft documented how DI Containers should integrate. The Simple Injector documentation states:
Please note that when integrating Simple Injector in ASP.NET Core, you do not replace ASP.NET’s built-in container, as advised by the Microsoft documentation. The practice with Simple Injector is to use Simple Injector to build up object graphs of your application components and let the built-in container build framework and third-party components
What this means is that, since the built-in container is still in place, resolving components using app.ApplicationServices.GetRequiredService<T>()—while they are registered in Simple Injector—will not work. In that case you are asking the built-in container and it doesn't know about the existence of those registrations.
Instead, you should resolve your type(s) using Simple Injector:
container.GetInstance<UserService>()
I'm using ASP.NET Core 2.1 RC1.
I'm also using Signal-R for it (found here):
https://learn.microsoft.com/en-us/aspnet/core/signalr/javascript-client?view=aspnetcore-2.1
I'm creating a .NET Core console application that's hosting Kestrel and using Signal-R. I've pretty much set it up exactly as the getting started documentation states for setting up the Startup.
This all works great. I'm able to connect to the it, get my HTML with signal-R script in it, receive messages I crafted with Clients.All.SendAsync. Works great.
BUT
I want to be able to send a message to clients, from outside the Hub. Where some event happens in my application, and a message is sent to clients. In full .NET, I'd use the GlobalHost and get the context. In ALL my searches on Stack Overflow, they reference something that no longer works, or used within an REST API controller that's passed in the IHubContext.
I have an event listener in my program.cs, and when the event is triggered, I'd love to be able to send a message to my UserInterfaceHub.
So -- how do I get the hub context in Program.CS - so I can send messages to it (call the SwitchUI method) from within an event delegate I have in Program.CS?
StartUp.cs
public void ConfigureServices(IServiceCollection services) {
services.Configure<CookiePolicyOptions>(options => {
options.CheckConsentNeeded = context => true;
options.MinimumSameSitePolicy = SameSiteMode.None;
});
services.AddMvc();
services.AddCors(options => options.AddPolicy("CorsPolicy",
builder => {builder.AllowAnyMethod().AllowAnyHeader().AllowAnyOrigin().AllowCredentials();}));
services.AddSignalR();
var provider = services.BuildServiceProvider();
}
public void Configure(IApplicationBuilder app, IHostingEnvironment env) {
if (env.IsDevelopment()) app.UseDeveloperExceptionPage();
app.UseStaticFiles();
app.UseCookiePolicy();
app.UseCors("CorsPolicy");
app.UseSignalR(routes => {routes.MapHub<UserInterfaceHub>("/uihub");});
app.UseMvc();
//app.Run(async (context) =>{await context.Response.WriteAsync("Active");});
}
Program.CS
CreateWebHostBuilder(args)
.UseKestrel()
.UseUrls("http://0.0.0.0:" + appProperties.HostPort.ToString().Trim())
.UseContentRoot(Directory.GetCurrentDirectory())
.UseIISIntegration()
.Build()
.Start();
UserInterfaceHub.cs
namespace InterfaceModule.Hubs {
public class UserInterfaceHub : Hub {
public async Task SwitchUI(string message) {
await Clients.All.SendAsync("ReceiveEvent", message);
}
public override async Task OnConnectedAsync() {
//await SwitchUI("HOWDY NEW PERSON!");
await base.OnConnectedAsync();
}
}
}
edit adding clarity.
In Program.CS, I have this event delegate:
//now that we're ready, start listening.
await
deviceClient.SetInputMessageHandlerAsync(ModuleProperties.InputName, OnReceiveEvent, deviceClient);
Console.WriteLine("INIT: Event Message Input handler created: [{0}]", ModuleProperties.InputName);
which is this:
static async Task<MessageResponse> OnReceiveEvent(Message message, object userContext) {
//HOW DO I REACH THE HUB FROM HERE SO I CAN SEND A MESSAGE TO THE LISTENERS?
}
I encountered a similar situation and here's how to resolve it:
In your Service layer, create an interface called something like ISendHubMessage. Have a method called Send() that takes parameters that you're wanting to send via SignalR. Create a class within the same file called SendHubMessage that implements the interface. Have it just do a return.
In your top-level project (where your Startup.cs file is located) create another class called SendHubMessage that implements that same ISendHubMessage interface from your Service layer. Within this SendHubMessage, you can use DI to get at the hub as explained above. This method will do the actual logic of sending via SignalR.
In your Startup ConfigureServices() method, add the following line:
services.AddTransient<"Service".ISendHubMessage, "TopLevel".SendHubMessage>();
(where "Service" is the namespace to your Service-level project and "TopLevel" in the namespace to your top-level project).
What you're doing with this line is saying "Whenever an object requests the ISendHubMessage dependency from the Service layer, supply it with the SendHubMessage class defined in my top-level project".
Finally, in all the places in code outside of your top-level project that you're wanting to send messages through your hub, inject that ISendHubMessage dependency in the constructor. You can then refer to it in the class methods and when you call Send(), it will call the Send() method defined in your SendHubMessage class in your top-level project.
This line of code:
app.UseSignalR(routes => {routes.MapHub<UserInterfaceHub>("/uihub");});
will register your hub with the DI container. Then to get access to it, you either use constructor injection to inject in the IHubContext<UserInterfaceHub> (this works for example in a Web Controller) or access it directly from the DI container by doing the following:
var hub = app.ApplicationServices.GetRequiredService<IHubContext<UserInterfaceHub>>();
(for example if executed in the startup.cs Configure method)
If you don't have access to the app.ApplicationServices which is basically an IServiceProvider at the location you need to access the hub, then you will need to either 1) get that class to work with dependency injection to inject in the IHubContext<UserInterfaceHub> or IServiceProvider 2) Setup a static Services global var via Configure so that you can have access to one of them globally, or find some other way to access the DI container (aka IServiceProvider) to get your hub via the above line of code.
Once you have your hub, then sending the message to the registered clients is a simple as calling the method on your hub.
await hub.Clients.All.SendAsync("ReceiveEvent", message);
You're question is a little unclear, but I'm assuming you mean you want to replace the following with something that can send a message through your hub:
app.Run(async (context) =>{await context.Response.WriteAsync("Active");});
Since this is in your Configure method, you can simply add IServiceCollection services to your Configure methods params. Then, you can do:
var hub = services.GetRequiredService<IHubContext<MyHub>>();
However, I'm not sure that this will actually do anything useful ultimately. At startup, you'd logically have no clients with subscriptions yet. As a result, sending a message through your hub at this point, would essentially go nowhere. By the time a user actually hits your site and gets connected to your hub, this part of your application has already run, and won't be hit again.
I am trying to inject a singleton of a service into an actor (Akka.NET) with ASP.NET Core's built-in DI container.
I have done the following in ConfigureServices:
public void ConfigureServices(IServiceCollection services)
{
// ..
// Register singleton of service
services.AddSingleton<IMyService, MyService>();
// Build service provider
var provider = services.BuildServiceProvider();
// Create actor system
var system = ActorSystem.Create("MyActorSystem");
// Inject service singleton into actor
directory.MyActorRef
= system.ActorOf(MyActor.Props(provider.GetService<IMyService>()), "myactor");
}
The issue is that the instance of MyService in the actor is different from the instance that is injected into the rest of the application - i.e. it is not a singleton.
What am I doing wrong and is there a better way of doing this?
That's because you create a separate IoC container inside your ConfigureServices
// Build service provider
var provider = services.BuildServiceProvider();
This line will create a new service provider (IoC container). When you resolve services from it, they are effectively singletons (since its not resolved from a scoped provider).
You shouldn't ever call .BuildServiceProvider() inside your ConfigureServices method, except when using 3rd party container and create it (i.e. when using Autofac).
Anyways, if you for some reason have to create the provider inside of ConfigureServices you need to change signature of ConfigureServices to
// Return value from void to IServiceProvider
public IServiceProvider ConfigureServices(IServiceCollection services)
{
var provider = services.BuildServiceProvider();
// don't call services.AddXxx(..) after this point! The container is already created and its registrations can't be changed
...
return provider;
}
This will make ASP.NET Core use this container instead of creating its own one and passing that to Configure Method.
While this may solve you immediate problem, its not very clean to do that kind of resolving inside ConfigureServices and you should use the docs (or ask a separate question) on how to correctly use DI with Akka.NET (Sorry not familiar with it, I'm Microsoft Orleans user :)).
A slightly better (still not fully correct since it works around the idea of DI) way would be to delay the instantiation of the actor until Configure method is called.
public void ConfigureServices(IServiceCollection services)
{
// ..
// Register singleton of service
services.AddSingleton<IMyService, MyService>();
}
public void Configure(IApplicationBuilder app)
{
// Create actor system
var system = ActorSystem.Create("MyActorSystem");
// Inject service singleton into actor
directory.MyActorRef
= system.ActorOf(MyActor.Props(app.ApplicationServices.GetService<IMyService>()), "myactor");
}
or
public void ConfigureServices(IServiceCollection services)
{
// ..
// Register singleton of service
services.AddSingleton<IMyService, MyService>();
}
// inject it in Configure
public void Configure(IApplicationBuilder app, IMyService myService)
{
// Create actor system
var system = ActorSystem.Create("MyActorSystem");
// Inject service singleton into actor
directory.MyActorRef
= system.ActorOf(MyActor.Props(myService), "myactor");
}
This will initialize and resolve your services in Configure.
Remarks regarding singletons, scopes and actors
P.S. keep in mind, you can't resolve scoped services from app.ApplicationServices or the service provider, it will throw an exception. This may become an issue when you want to use DbContext which, by default is registered as scoped service.
You can also register it as scoped with an override to AddDbContext, but be aware of "memory leaks", as the number of tracked objects grows, so will the memory consumption (and big number of tracked entities (>=10k) will decrease your tracker related operations significantly).
And with DbContext in mind, also keep in mind that EF and EF Core are not thread-safe, and can't be accessed by threads (or run multiple asynchronous operations, i.e. starting 5 queries w/o awaiting and then using await Task.WaitAll(...)).
While an actor is guaranteed to only be accessed by a single thread at a single time, the services aren't if you scope them.
How well this works depends on the Task Scheduler implementation used by Akka.NET (again, not familiar with it's internals - i.e. Orleans abstracts persistence behind storage providers).
I am trying to migrate from .NET Core 1.1 to 2.0, and am stuck migrating the JWT Token configuration. I have an interface/class that provides the JWTBearerOptions, and in .NET Core 2.0 I cannot access my DI Graph objects (since in 2.0, JWT is configured in the ConfigureServices() function). I want to keep my Startup.cs file clean of so many lines of code configuring JWT.
Is there any way to delegate the JWTBearerOptions object creation to a provider created through DI? I want something like the below:
public virtual void ConfigureServices(IServiceCollection services)
{
services.AddAuthentication()
.AddJwtBearer(MyAuthicationScheme.JwtAuthName, options =>
{
myInjectedInstance.SetJwtBearOptions(options, Configuration);
})
}
#flodin
I came across this same problem for the AddJwtBearer and there is a cludgey way to get access to the HttpContext by plugging into OnMessageRecieved Events
jwt.Events = new Microsoft.AspNetCore.Authentication.JwtBearer.JwtBearerEvents()
{
OnMessageReceived = context =>
{
// setting the issuer validator delegate here instead of in the jwt.TokenValidationParameters
// allows for accessing the HttpContext items and DI container
context.Options.TokenValidationParameters.IssuerValidator = (issuer, token, parameters) =>
{
// di in callbacks!
var test = context.HttpContext.RequestServices.GetService<ITenant>();
return Task.CompletedTask;
}
Found the answer on microsoft's docs. It is impossible to access DI objects during the ConfigureServices call: https://learn.microsoft.com/en-us/aspnet/core/fundamentals/configuration/index?tabs=basicconfiguration#additional-notes
I have ASP.NET Web API application. The application is using Unity as IoC container. The application is also using Hangfire and I am trying to configure Hangfire to use Unity.
So based on documentation i am using Hangfire.Unity which registers the unity container as a current job activator in Hangfire.
I have a class which has dependency on IBackgroundJobClient
public class MyService
{
private MyDBContext _dbContext = null;
private IBackgroundJobClient _backgroundJobClient = null;
public MyService(MyDbContext dbContext, IBackgroundJobClient backgroundJobClient)
{
_dbContext = dbContext;
_backgroundJobClient = backgroundJobClient;
}
}
However even after configuring Hangfire.Unity it could not create & pass instance of BackgroundJobClient
So i had to register every dependency of BackgroundJobClient with unity container.
Unity Registration
public class UnityConfig
{
private static Lazy<IUnityContainer> container = new Lazy<IUnityContainer>(() =>
{
var container = new UnityContainer();
RegisterTypes(container);
return container;
});
public static IUnityContainer GetConfiguredContainer()
{
return container.Value;
}
public static void RegisterTypes(IUnityContainer container)
{
container.RegisterType<MyDbContext>(new HierarchicalLifetimeManager(), new InjectionFactory(x => new MyDbContext()));
// register hangfire dependencies
container.RegisterType<IBackgroundJobClient, BackgroundJobClient>();
container.RegisterType<JobStorage, SqlServerStorage>(new InjectionConstructor("HangfireConnectionString"));
container.RegisterType<IJobFilterProvider, JobFilterAttributeFilterProvider>(new InjectionConstructor(true));
container.RegisterType<IBackgroundJobFactory, BackgroundJobFactory>();
container.RegisterType<IRecurringJobManager, RecurringJobManager>();
container.RegisterType<IBackgroundJobStateChanger, BackgroundJobStateChanger>();
}
}
OWIN Startup
public class Startup
{
public void Configuration(IAppBuilder app)
{
var container = UnityConfig.GetConfiguredContainer();
Hangfire.GlobalConfiguration.Configuration.UseSqlServerStorage("HangfireConnectionString");
Hangfire.GlobalConfiguration.Configuration.UseUnityActivator(container);
// if i dont call UseSqlServerStorage() above then UseHangfireDashboard() method fails with exception
//JobStorage.Current property value has not been initialized. You must set it before using Hangfire Client or Server API.
app.UseHangfireDashboard();
app.UseHangfireServer();
RecurringJob.AddOrUpdate<MyService>(x => x.Prepare(), Cron.MinuteInterval(10));
}
}
Code is working with such configuration. However i have questions:
Is this the correct way of configuring Unity with Hangfire?
Why do i need to invoke Hangfire.GlobalConfiguration.Configuration.UseSqlServerStorage("HangfireConnectionString") in OWIN startup even though SqlServerStorage is already registered with Unity container as JobStorage?
If i dont invoke UseSqlServerStorage() method in OWIN startup then i get exception on app.UseHangfireDashboard() method.
JobStorage.Current property value has not been initialized. You must
set it before using Hangfire Client or Server API.
I believe there is a problem where you want to kick off Hangfire outside of the Unity ecosystem, but also want Unity to understand how to instantiate the appropriate Hangfire interfaces with the associated implementations. Since Hangfire itself doesn't use Unity, you will need to start up Hangfire with the appropriate configuration, such as the SQL Server connection string, and then use that configuration to inform Unity how to instantiate the Hangfire interfaces. I was able to solve this problem by setting the global Hangfire configuration for SQL and then use that same Hangfire static instance to set up Unity.
Here's example code where first you will see how I start the hangfire dashboard and server with a connection string:
public void Configuration(IAppBuilder app)
{
var configuration = new Configuration(); // whatever this is for you
GlobalConfiguration.Configuration.UseSqlServerStorage(
configuration.GetConnectionString());
GlobalConfiguration.Configuration.UseActivator(
new HangfireContainerActivator(UnityConfig.GetConfiguredContainer()));
app.UseHangfireDashboard("/hangfire", new DashboardOptions
{
Authorization = new[] {new HangfireAuthorizationFilter()}
});
app.UseHangfireServer();
}
As the second example, here's the configuration of Unity for Hangfire; notice how this code is using the static JobStorage Hangfire object to instantiate any requests for JobStorage.
public static void RegisterHangfire(IUnityContainer container)
{
container.RegisterType<JobStorage>(new InjectionFactory(c => JobStorage.Current));
container.RegisterType<IJobFilterProvider, JobFilterAttributeFilterProvider>(new InjectionConstructor(true));
container.RegisterType<IBackgroundJobFactory, BackgroundJobFactory>();
container.RegisterType<IRecurringJobManager, RecurringJobManager>();
container.RegisterType<IBackgroundJobClient, BackgroundJobClient>();
container.RegisterType<IBackgroundJobStateChanger, BackgroundJobStateChanger>();
}
I believe this approach gives you the best of both worlds where you only set up your SQL Server connection once and you do it early to kick off Hangfire, but then you use that instance to tell Unity how to behave.