I am working on an application built on asp.net core 3.1 + Autofac as DI. Now i want to implement multi tenant feature. I am able to register tenant specific services and it is working as expected.
What i want to achieve is to register tenant specific controller to override default controller registered in main/application level container.
I have registered custom IApplicationFeatureProvider to register only main controllers.
here is the code.
//Startup.cs
public class StartUp
{
void ConfigureServices(IServiceCollection services)
{
services.AddControllers().ConfigureApplicationPartManager(apm =>
{
apm.FeatureProviders.RemoveAt(0); //remove default controller feature provider
apm.FeatureProviders.Add(new MyControllerFeatureProvider()); //register custom provider
}).AddControllersAsServices();
services.AddAutofacMultitenantRequestServices();
//rest of the configuration
}
public void ConfigureContainer(ContainerBuilder builder)
{
//registration of global or main services
builder.RegisterType<MyTenantIdentificationStrategy>()
.As<ITenantIdentificationStrategy>().SingleInstance(); //Get Tenant from request header
builder.Register(container =>
{
ITenantIdentificationStrategy strategy =
container.Resolve<ITenantIdentificationStrategy>();
// tenant resolution code
return new Tenant();
}).InstancePerLifetimeScope();
}
public static MultitenantContainer ConfigureMultitenantContainer(IContainer container)
{
var strategy <-- resolved from container
MultitenantContainer mtc = new MultitenantContainer(strategy, container);
mtc.ConfigureTenant(1, cb => {
cb.RegisterType<IP.Controllers.Extended.HomeController>).InstancePerLifetimeScope();
});
return mtc;
}
}
//HomeController.cs
namespace IP.Controllers
{
[Route("[controller]")]
public class HomeController : ControllerBase
{
}
[Route("Get")
public IActionResult Get()
{
return new JsonResult(new {Main = true});
}
}
//HomeController1.cs
namespace IP.Controllers.Extended <-- different namespace
{
[Route("[controller]")]
public class HomeController : ControllerBase
{
}
[Route("Get")
public IActionResult Get()
{
return new JsonResult(new {Main = false});
}
}
//program.cs
public class Program
{
public static void Main(string[] args)
{
CreateHostBuilder(args).Build().Run();
}
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.UseServiceProviderFactory(new AutofacMultitenantServiceProviderFactory(Startup.ConfigureMultitenantContainer))
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseStartup<Startup>();
});
}
http://localhost:8082/Home/Get [Without tenantid in header]
http://localhost:8082/Home/Get [Without tenantid=1 in header]
In both case main home controller is resolved not tenant specific..
Any help well be appreciated.
Answer to my own question,
Routing and controller selection is handled Asp.Net Core not by Autofac.
I am registering tenant specific controllers in ConfigureTenant method. Asp.Net Core Framework is not aware about these controllers. So for given route framework always selects registered controller not extended one registered in ConfigureTenant method.
So first i have removed custom application feature provider. Now all controllers in current assembly are registered. Then removed separate registration of controllers from ConfigureTenant method. Now framework throws ambiguity exception because there are two controllers with same route.
From stack trace, i found that EndPointResolver implementation is throwing ambiguity exception. Since we can provide our own implementation for EndPointResolver, i create custom EndPointResolver and register it.
Now during route selection, if there is ambiguity while selecting controller, i just retrieve tenant information from request header and based on Tanent i am handling ambiguity exception.
I am not sure if it is the correct approach but now i am able to register controller with same name [same Route] in different namespace/assembly.
I'm following guidelines in how to setup EF Core to work safely in Blazor & .NET Core 3.1.
The MS documentation is here: https://learn.microsoft.com/en-us/aspnet/core/blazor/blazor-server-ef-core?view=aspnetcore-3.1
In the instructions, advice is to create a DbContextFactory which is used to create a dbcontext in each service. All makes sense in the Blazor world, but the code won't compile as
AddDbContextFactory does not exist. If there's another way to do it in .Net Core 3.1/ EF Core 3 - I can't see it.
services.AddDbContextFactory<ContactContext>(opt =>
opt.UseSqlite($"Data Source={nameof(ContactContext.ContactsDb)}.db")
.EnableSensitiveDataLogging());
I found this extension method that the Microsoft docs page is using in its sample github project:
public static IServiceCollection AddDbContextFactory<TContext>(
this IServiceCollection collection,
Action<DbContextOptionsBuilder> optionsAction = null,
ServiceLifetime contextAndOptionsLifetime = ServiceLifetime.Singleton)
where TContext : DbContext
{
// instantiate with the correctly scoped provider
collection.Add(new ServiceDescriptor(
typeof(IDbContextFactory<TContext>),
sp => new DbContextFactory<TContext>(sp),
contextAndOptionsLifetime));
// dynamically run the builder on each request
collection.Add(new ServiceDescriptor(
typeof(DbContextOptions<TContext>),
sp => GetOptions<TContext>(optionsAction, sp),
contextAndOptionsLifetime));
return collection;
}
And the factory class is here:
public class DbContextFactory<TContext>
: IDbContextFactory<TContext> where TContext : DbContext
{
private readonly IServiceProvider provider;
public DbContextFactory(IServiceProvider provider)
{
this.provider = provider;
}
public TContext CreateDbContext()
{
if (provider == null)
{
throw new InvalidOperationException(
$"You must configure an instance of IServiceProvider");
}
return ActivatorUtilities.CreateInstance<TContext>(provider);
}
}
GetOptions method:
private static DbContextOptions<TContext>
GetOptions<TContext>(Action<DbContextOptionsBuilder> action,
IServiceProvider sp = null) where TContext: DbContext
{
var optionsBuilder = new DbContextOptionsBuilder < TContext > ();
if (sp != null)
{
optionsBuilder.UseApplicationServiceProvider(sp);
}
action?.Invoke(optionsBuilder);
return optionsBuilder.Options;
}
AddDbContextFactory will be introduced in .NET Core 5. See here: https://devblogs.microsoft.com/dotnet/announcing-entity-framework-core-ef-core-5-0-preview-7/.
The page you linked to gives you the code (albeit in pieces) to roll your own.
You will have to add the AddDbContextFactory<TContext> class and the FactoryExtensions to your project. Download the sample app there to make it complete.
And when you upgrade to net5 just replace it with the library version.
I'm building a service application using Web API, .Net Core and EntityFramework Core.
For configuring options in my DbContext I'm using these lines in "ConfigureServices" method in Startup.cs
var connection = #"Server=ISSQLDEV;Database=EventManagement;Trusted_Connection=True;";
services.AddDbContext<EMContext>(options => options.UseSqlServer(connection));
I know that if I add the context as a constructor parameter in the controller .Net will inject the context in the constructor.
But this is not the behavior I want. I don't want my web api to know anything about the dbcontext. I have a DataAccess Project with a repository class that handles all CRUD operations.
This means that I just want to say Repository.AddEvent(evt) in my controller and then repository knows how to handle that.
On the other hand, repository uses a simple dependency resolver to get the right "IDataAdapter" implementation. One of those implementations is SQLDataAdapter. This is the point I need my context.
How can I pass my context all the way to this point?
You can solve this by adding your dbcontext via constructor injection to your classes from your data access layer.
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
services.AddDbContext<ApplicationDbContext>(o => o.UseSqlServer(myConnStr));
services.AddScoped<Repository>(); // 'scoped' in ASP.NET means "per HTTP request"
}
}
public class MvcController
{
private Repository repo;
public MvcController(Repository repo)
{
this.repo = repo;
}
[HttpPost]
public void SomeEndpoint()
{
this.repo.AddFoo(new Foo());
}
}
public class Repository
{
private DbContext db;
public Repository(ApplicationDbContext db)
{
this.db = db;
}
public void AddFoo(Foo obj)
{
this.db.Set<Foo>().Add(obj);
this.db.SaveChanges();
}
}
If you want to further customize how your DbContext is injected into your DI container, I suggest you look at what .AddDbContext is actually doing. See https://github.com/aspnet/EntityFramework/blob/1.0.0/src/Microsoft.EntityFrameworkCore/EntityFrameworkServiceCollectionExtensions.cs#L142-L158
I am using Entity Framework 7 on the nightly build channel (right now I'm using version EntityFramework.7.0.0-beta2-11524) and I'm trying to log the queries that EF generates just out of curiosity.
I'm writing a simple console program, I tried using the same logging technic that EF6 uses, but DbContext.Database.Logis not available on Entity Framework 7. Is there a way to log or just take a peek at the SQL generated by EF7?
For those using EF7 none of the above worked for me. But this is how i got it working. (from #avi cherry's comment)
In your Startup.cs you proably have a Configure method with a bunch of configurations in it. It should look like below (in addition to your stuff).
public void Configure(IApplicationBuilder app, ILoggerFactory loggerFactory)
{
//this is the magic line
loggerFactory.AddDebug(LogLevel.Debug); // formerly LogLevel.Verbose
//your other stuff
}
You can log to the console using this code, I am sure it will be wrapped in a simpler api later:
using System;
using Microsoft.Data.Entity.Infrastructure;
using Microsoft.Data.Entity.Utilities;
using Microsoft.Framework.Logging;
public static class SqlCeDbContextExtensions
{
public static void LogToConsole(this DbContext context)
{
var loggerFactory = ((IAccessor<IServiceProvider>)context).GetService<ILoggerFactory>();
loggerFactory.AddProvider(new DbLoggerProvider());
}
}
And the DbLoggerProvider is implemented here: https://github.com/ErikEJ/EntityFramework7.SqlServerCompact/tree/master/src/Provider40/Extensions/Logging
If you are using MS SQL Server, one way I have used in the past is to make use of the SQL Server Profiler and capture all interaction with the SQL Server, this captures the exact SQL submitted and can be cut n pasted into the SQL Server Management Studio for further review/analysis.
I know this does not directly answer your question on Entity Framework, but I have found this generic approach very useful for any language/tools.
One tip is in the Trace Properties when setting up a new trace, I have found it useful to adjust the default selection of events in the Events Selection tab. Mostly I turn off the Audit Login/Logout unless specifically tracking such an issue.
I struggled with all the above answers as the EF bits kept changing, so the code wouldn't compile. As of today (19Feb2016) with EF7.0.0-rc1-final (Prerelease) and SQLite, here's what works for me:
From the EF7 documentation:
using System;
using System.IO;
using Microsoft.Extensions.Logging;
namespace EFLogging
{
public class EFLoggerProvider : ILoggerProvider
{
public ILogger CreateLogger(string categoryName)
{
return new EFLogger();
}
public void Dispose()
{
// N/A
}
private class EFLogger : ILogger
{
public IDisposable BeginScopeImpl(object state)
{
return null;
}
public bool IsEnabled(LogLevel logLevel)
{
return true;
}
public void Log(LogLevel logLevel, int eventId, object state, Exception exception, Func<object, Exception, string> formatter)
{
File.AppendAllText(#".\EF.LOG", formatter(state, exception));
Console.WriteLine(formatter(state, exception));
}
}
}
}
Using some ideas above and the EF7 Docs:
using System;
using Microsoft.Data.Entity;
using Microsoft.Data.Entity.Infrastructure;
using Microsoft.Extensions.DependencyInjection; // Add this to EF7 docs code
using Microsoft.Extensions.Logging;
namespace DataAccessLayer
{
public static class DbContextExtensions
{
public static void LogToConsole(this DbContext context)
{
var serviceProvider = context.GetInfrastructure<IServiceProvider>();
var loggerFactory = serviceProvider.GetService<ILoggerFactory>();
loggerFactory.AddProvider(new EFLoggerProvider(logLevel));
}
}
}
EDIT: #jnm2 pointed out if you add "using Microsoft.Extensions.DependencyInjection", the EF7 docs ARE correct. Thanks!
And finally, in my App.OnStartup method:
using (var db = new MyDbContext())
{
db.LogToConsole();
}
This code will create a log file and also output logging info to the Visual Studio output window. I hope this helps -- I'm sure in a few weeks, the bits will change again.
With the latest version of EF7-beta8, Anthony's answer need a little tweaking. Here's what I did to get it to work.
internal static class DbContextExtensions
{
public static void LogToConsole(this DbContext context)
{
var loggerFactory = context.GetService<ILoggerFactory>();
loggerFactory.AddConsole(LogLevel.Verbose);
}
}
I think I figured this out. With the current EF7 bits, ILoggerFactory is registered with the dependency injection container which EF is using. You can get a reference to the container, which is an IServiceProvider, via the ScopedServiceProvider property of DbContext when it is cast to IDbContextServices. From there, you can get the ILoggerFactory and configure it using the AddToConsole extension method from the Microsoft.Framework.Logging.Console NuGet package.
public static void LogToConsole(this DbContext context)
{
// IServiceProvider represents registered DI container
IServiceProvider contextServices = ((IDbContextServices)context).ScopedServiceProvider;
// Get the registered ILoggerFactory from the DI container
var loggerFactory = contextServices.GetRequiredService<ILoggerFactory>();
// Add a logging provider with a console trace listener
loggerFactory.AddConsole(LogLevel.Verbose);
}
Here is a gist I created for this snippet: https://gist.github.com/tonysneed/4cac4f4dae2b22e45ec4
This worked for me with EF7 rc2-16485:
"EntityFramework.MicrosoftSqlServer": "7.0.0-rc2-16485",
"Microsoft.Extensions.Logging.Console": "1.0.0-rc2-15888",
public static class DbContextExtensions
{
public static void LogToConsole(this DbContext context)
{
var contextServices = ((IInfrastructure<IServiceProvider>) context).Instance;
var loggerFactory = contextServices.GetRequiredService<ILoggerFactory>();
loggerFactory.AddConsole(LogLevel.Verbose);
}
}
As an alternative to the above answers, I found this answer by far the easiest solution for me to reason about:
private readonly ILoggerFactory loggerFactory;
// Using dependency injection
public FooContext(ILoggerFactory loggerFactor) {
this.loggerFactory = loggerFactory;
}
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) {
optionsBuilder.UseLoggerFactory(loggerFactory); // Register logger in context
}
With ASP.NET Core 2.0 you get SQL logging automatically. No need to do anything extra.
For those who just want SQL queries to be logged (using Entity Framework Core with .NET Core 2.0 or above), use the following code in your DbContext class:
public static readonly LoggerFactory MyLoggerFactory
= new LoggerFactory(new[]
{
new ConsoleLoggerProvider((category, level)
=> category == DbLoggerCategory.Database.Command.Name
&& level == LogLevel.Information, true)
});
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
=> optionsBuilder
.UseLoggerFactory(MyLoggerFactory) // Warning: Do not create a new ILoggerFactory instance each time
.UseSqlServer(
#"Server=(localdb)\mssqllocaldb;Database=EFLogging;Trusted_Connection=True;ConnectRetryCount=0");
Reference: https://learn.microsoft.com/en-us/ef/core/miscellaneous/logging
I am using Ninject in my ASP MVC 3 project, I have modified the global.asax file (as normally done) and then created a class NinjectControllerFactory like this:
public class NinjectControllerFactory : DefaultControllerFactory
{
private IKernel ninjectKernel;
public NinjectControllerFactory()
{
ninjectKernel = new StandardKernel();
AddBindings();
}
protected override IController GetControllerInstance(RequestContext requestContext,
Type controllerType)
{
return controllerType == null
? null
: (IController)ninjectKernel.Get(controllerType);
}
private void AddBindings()
{
// put additional bindings here
ninjectKernel.Bind<IServiceName>().To<ConcreteClass>();
}
}
All this works fine.
Now I want to add my Entity framework context object to the binding, so that I do not have to create a new instance of it for each service.
Can anyone tell how to do it?
Should I create a new interface which just defines a Entity framework context?
Thanks
You could use self-binding
kernel.Bind<MyDbContext>().ToSelf();
P.S you should also check-out Ninject.MVC3 package on nuget