I have the following setup:
public interface ISomeService : IService, INonServiceFabricService
{
}
Where INonServiceFabricService is an interface with no Service Fabric dependencies to allow me to de-couple my application code from infrastructure:
public interface INonServiceFabricService
{
Task DoSomething();
}
My implementation then inherits from ISomeService:
public class ActualService : StatefulService, ISomeService
{
public Task DoSomething()
{
// Something
}
}
Everything builds and runs fine but when I try to create a proxy:
var proxy = ServiceProxy.Create<ISomeService>(Uri, new ServicePartitionKey(0));
I get the following error:
The type 'ISomeService' is not an service interface as it does not
derive from the interface 'INonServiceFabricService'
So it turns out it isn't possible to do this.
Every interface your Service Fabric service interface (e.g, ISomeService in question) inherits from must derive from IService. See here.
The error should really say:
The type 'INonServiceFabricService' is not an service interface as it
does not derive from the interface 'IService'
Related
According to https://learn.microsoft.com/en-us/azure/azure-functions/functions-dotnet-dependency-injection the service provider should not be used until AFTER the startup has completed running. Indeed, if I try to get a registered service it will fail.
Example:
[assembly: FunctionsStartup(typeof(Startup))]
namespace Fx {
public sealed class Startup : FunctionsStartup {
public override void Configure(IFunctionsHostBuilder builder) {
var configurationBuilder = new ConfigurationBuilder();
configurationBuilder.AddEnvironmentVariables();
var configuration = configurationBuilder.Build();
builder.Services.AddInfrastructure(configuration);
builder.Services.AddApplication();
var serviceProvider = builder.Services.BuildServiceProvider();
DependencyInjection.AddDatabase(serviceProvider).GetAwaiter().GetResult();
}
}
}
public static class DependencyInjection {
public static async Task AddDatabase(IServiceProvider services) {
using var scope = services.CreateScope();
var serviceProvider = scope.ServiceProvider;
var context = serviceProvider.GetRequiredService<ApplicationDbContext>();
//Error generated here
if (context.Database.IsSqlServer()) {
await context.Database.MigrateAsync();
}
await ApplicationDbContextSeed.SeedSamplePersonnelDataAsync(context);
}
public static IServiceCollection AddInfrastructure(
this IServiceCollection services,
IConfiguration configuration) {
services.AddDbContext<ApplicationDbContext>(options =>
options.UseSqlServer(configuration.GetConnectionString("DefaultConnection"),
b => b.MigrationsAssembly(typeof(ApplicationDbContext).Assembly.FullName)));
services.AddScoped<IApplicationDbContext>(provider => provider.GetService<ApplicationDbContext>());
return services;
}
}
This produces the following error
Microsoft.EntityFrameworkCore: No database provider has been configured for this DbContext. A provider can be configured by overriding the DbContext.OnConfiguring method or by using AddDbContext on the application service provider. If AddDbContext is used, then also ensure that your DbContext type accepts a DbContextOptions<TContext> object in its constructor and passes it to the base constructor for DbContext.
Is there a good option for migrating and seeding during startup?
The easiest way I found to run code after startup was by registering a custom IWebJobsStartup by using the WebJobsStartupAttribute (the FunctionsStartupAttribute actually also inherits from this attribute). In the WebJobsStartup class you'll need to register your extension using the AddExtension where you are able to use dependency injection and seed your database. My code:
[assembly: WebJobsStartup(typeof(DbInitializationService), "DbSeeder")]
namespace Our.Database.Seeder
{
public class DbInitializationService : IWebJobsStartup
{
public void Configure(IWebJobsBuilder builder)
{
builder.AddExtension<DbSeedConfigProvider>();
}
}
[Extension("DbSeed")]
internal class DbSeedConfigProvider : IExtensionConfigProvider
{
private readonly IServiceScopeFactory _scopeFactory;
public DbSeedConfigProvider(IServiceScopeFactory scopeFactory)
{
_scopeFactory = scopeFactory;
}
public void Initialize(ExtensionConfigContext context)
{
using var scope = _scopeFactory.CreateScope();
var dbContext = scope.ServiceProvider.GetService<YourDbContext>();
dbContext.Database.EnsureCreated();
// Further DB seeding, etc.
}
}
}
According to your code, I assume that you're building something aligned to the CleanArchitecture Repository on Github. https://github.com/jasontaylordev/CleanArchitecture
The main difference between this repo and your apporach, is that you're obviously not using ASP.NET, which is not a problem at all, but requires a little bit more configuration work.
The article already mentioned (https://markheath.net/post/ef-core-di-azure-functions) refers another blogpost (https://dev.to/azure/using-entity-framework-with-azure-functions-50aa), which briefly explains that EntityFramework Migrations are not capable of auto-discovering your migrations in an Azure Function. Therefore, you need to implement an instance of IDesignTimeDbContextFactory. I also stumbled upon it in the microsoft docs:
https://learn.microsoft.com/en-us/ef/core/cli/dbcontext-creation?tabs=dotnet-core-cli#from-a-design-time-factory
You could for example place it inside your Infrastructure\Persistence\Configurations folder. (Once again, I'm only assuming that you're following the CleanArchitecture repo structure)
DI in AZURE Functions
Caveats
A series of registration steps run before and after the runtime processes the startup class. Therefore, keep in mind the following items:
The startup class is meant for only setup and registration. Avoid using services registered at startup during the startup process. For instance, don't try to log a message in a logger that is being registered during startup. This point of the registration process is too early for your services to be available for use. After the Configure method is run, the Functions runtime continues to register additional dependencies, which can affect how your services operate.
The dependency injection container only holds explicitly registered types. The only services available as injectable types are what are setup in the Configure method. As a result, Functions-specific types like BindingContext and ExecutionContext aren't available during setup or as injectable types
Is it possible to call services or actors from one application to another in a Service Fabric Cluster ? When I tryed (using ActorProxy.Create with the proper Uri), I got a "No MethodDispatcher is found for interface"
Yes, it is possible. As long as you have the right Uri to the Service (or ActorService) and you have access to the assembly with the interface defining your service or actor the it should not be much different than calling the Service/Actor from within the same application. It you have enabled security for your service then you have to setup the certificates for the exchange as well.
If I have a simple service defined as:
public interface ICalloutService : IService
{
Task<string> SayHelloAsync();
}
internal sealed class CalloutService : StatelessService, ICalloutService
{
public CalloutService(StatelessServiceContext context)
: base(context) { }
protected override IEnumerable<ServiceInstanceListener> CreateServiceInstanceListeners()
{
yield return new ServiceInstanceListener(this.CreateServiceRemotingListener);
}
public Task<string> SayHelloAsync()
{
return Task.FromResult("hello");
}
}
and a simple actor:
public interface ICalloutActor : IActor
{
Task<string> SayHelloAsync();
}
[StatePersistence(StatePersistence.None)]
internal class CalloutActor : Actor, ICalloutActor
{
public CalloutActor(ActorService actorService, ActorId actorId)
: base(actorService, actorId) {}
public Task<string> SayHelloAsync()
{
return Task.FromResult("hello");
}
}
running in a application like this:
Then you can call it from another application within the same cluster:
// Call the service
var calloutServiceUri = new Uri(#"fabric:/ServiceFabric.SO.Answer._41655575/CalloutService");
var calloutService = ServiceProxy.Create<ICalloutService>(calloutServiceUri);
var serviceHello = await calloutService.SayHelloAsync();
// Call the actor
var calloutActorServiceUri = new Uri(#"fabric:/ServiceFabric.SO.Answer._41655575/CalloutActorService");
var calloutActor = ActorProxy.Create<ICalloutActor>(new ActorId(DateTime.Now.Millisecond), calloutActorServiceUri);
var actorHello = await calloutActor.SayHelloAsync();
You can find the right Uri in the Service Fabric Explorer if you click the service and look at the name. By default the Uri of a service is: fabric:/{applicationName}/{serviceName}.
The only tricky part is how do you get the interface from the external service to your calling service? You could simply reference the built .exe for the service you wish to call or you could package the assembly containing the interface as a NuGet package and put on a private feed.
If you don't do this and you instead just share the code between your Visual Studio solutions the Service Fabric will think these are two different interfaces, even if they share the exact same signature. If you do it for a Service you get an NotImplementedException saying "Interface id '{xxxxxxxx}' is not implemented by object '{service}'" and if you do it for an Actor you get an KeyNotfoundException saying "No MethodDispatcher is found for interface id '-{xxxxxxxxxx}'".
So, to fix your problem, make sure you reference the same assembly that is in the application you want to call in the external application that is calling.
Much ink has flowed about Sf2 controller/container. I face with follow situation:
app/console container:debug security
...
> 4
[container] Information for service security.token_storage
Service Id security.token_interface
Class Symfony\Component\Security\Core\Authentication\Token ...
...
Public yes
LoginBundle\DefaultController.php
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
class DefaultController extends Controller
{
public function indexAction()
{
dump(Controller::get('security.token_storage'));
...
works OK, obviously.
LoginBundle\UserUtilsController
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
class UserUtilsController extends Controller
{
public function getRoleById()
{
dump(Controller::get('security.token_storage'));
...
throw: Error: Call to a member function get() on a non-object
In Sf2 Book - Service container I found:
In this example, the controller extends Symfony's base Controller, which gives you access to the service container itself. You can then use the get method to locate and retrieve the my_mailer service from the service container.
The misunderstanding is:
- Both controllers extends basic controller which itself extends ContainerAware which implements ContainerAwareInterface which set container.
- Both controllers access same public service container.
So, why the second controller it doesn't work?
I know that the question is old but I don't want to inject a controller as service and I think it is redundant and wrong to redeclare a public service in services.yml
Thank you in advance.
I found the answer myself and I want to share for every one is in same situation...
The UserUtilsController doesn't work because it's not working in this manner. The Symfony architecture is interesting if you get to know it.
LoginBundle\Controller\UserUtilsController
// For this job we don't need to extends any class..
class UserUtilsController
{
// but we need a property for injecting the service in it
private $token;
// Now let's inject service into our property $token
public function __construct($token)
{
$this->token = $token;
}
// It's not done but let pretend it is and let's use it
public function getRoleById()
{
...
return $this->token->getToken()->getRoles();
...
services.yml
#here it's the magic
services:
# this is a new services container
user.loggeduser_utils:
# this is my class (second class)
class: LoginBundle\Controller\UserUtilsController
# this is how I feed my _construct argument
arguments: ["#security.token_storage"]
So I just inject an existing service in my new class.
Now, to use this we must to call in first class:
LoginBundle\Controller\DefaultController.php
class DefaultController extends Controller
{
public function indexAction()
{
// because my class is now a service container we call in this way
$userRoleId = $this->get('user.loggeduser_utils');
...
This solution above is almost trivial simple AFTER understanding the Sf2 DI model.
I have a Service that need inject more than one provider, see below for example. How to use Unity to implement this feature?
public class MyService: IMyService
{
public MyService(IEnumerable<Provider> Providers);
}
I know this is an old question, but maybe this will help someone else that stumbles upon this.
As long as you register the implementations with a specific name, this is possible to easily inject. You will then get all registered implementations.
public class MyService: IMyService
{
public MyService(IProvider[] providers)
{
// Do something with the providers
}
}
Just make sure to inject them as an array. Unity will understand this. And when you register them you can register them as such:
container.RegisterType<IProvider, FooProvider>("Foo");
container.RegisterType<IProvider, BarProvider>("Bar");
One way is to inject the UnityContainer itself, and then resolve all the Providers you need:
public class MyService : IMyService
{
public class MyService(IUnityContainer iocContainer)
{
var providers = iocContainer.ResolveAll<IProvider>();
}
}
The only thing you will need to do is register the UnityContainer with itself somewhere on setup:
unityContainer.Register<IUnityContainer>(unityContainer, new ContainerControllerLifetimeManager());
I need to modify an existing web app to use Castle.Windsor as IOC container. It was originally developed with StructureMap.
I am stuck with the following problem.
Lets say I have registered a couple of interfaces and their corresponding implementations:
IFoo -> Foo
IBar -> Bar
Calling container.Resolve<IFoo>() or container.Resolve<IBar>() works just fine. This means that the services are registered correctly.
I have a Web Api class with dependencies on other services, such as IFoo
public class BadRequestErrorHandler : HttpErrorHandler
{
// services
public BadRequestErrorHandler(IFoo foo) {...} // has dependency on IFoo
}
In StructureMap I can call:
var test = ObjectFactory.GetInstance<BadRequestErrorHandler>();
this will resolve the IFoo dependency.
Now this does not work with windsor.
How can this be achieved with windsor?
Thanks!
* EDIT *
I was just able to make it work by explicitely registering the BadRequestErrorHandler.
container.Register(Component.For<BadRequestErrorHandler>());
I am just hoping there is a better way to achieve this, that does not involve registering classes that have dependencies. I have a bunch of them...
* EDIT 2 **
To ease the pain, I added a special method to deal with these concrete types.
public T GetInstanceWithAutoRegister<T>()
{
if (container.Kernel.GetHandler(typeof(T)) == null)
{
container.Register(Component.For<T>());
}
return container.Resolve<T>();
}
public object GetInstanceWithAutoRegister(Type pluginType)
{
if (container.Kernel.GetHandler(pluginType) == null)
{
container.Register(Component.For(pluginType));
}
return container.Resolve(pluginType);
}
not ideal, but at least better than having to explicetly register each type. Hope someone has a better solution
You can achieve what you want by registering an ILazyComponentLoader which is a hook that gets called by Windsor as a "last resort" when a component cannot be resolved.
In your case, the implementation would probably look somewhat like this:
public class JustLetWindsorResolveAllConcreteTypes : ILazyComponentLoader
{
public IRegistration Load(string key, Type service)
{
return Component.For(service);
}
}
-and then it should be registered as such:
container.Register(Component.For<ILazyComponentLoader>()
.ImplementedBy<JustLetWindsorResolveAllConcreteTypes>());
You can read more about it in the docs.