Support for MassTransit

[Bru456]

I would love to use Finbuckle with MassTransit https://masstransit.io/.

The use case would be to offload tenant data processing to other microservices. To achieve this the tenant context would need to be passed and retrieved in background jobs and services through a Message Broker. Not via standard HTTP requests.

The following would be classed as acceptance criteria:

1. Inject the current tenantId into the message envelope header via the publisher
2. Inject the TenantInfo via dependency injection into the consumer

The way I am thinking this might be possible to achieve is through:

• Creating a middleware for MassTranist that would add the Tenant ID to the messages envelope header using a filter https://masstransit.io/documentation/configuration/middleware.
  • publish and consume messages
• Create a new strategy for Finbuckle to use the MassTranist header and identify tenant.
• Create a Tenant Accessor to be able to retrieve the Tenant outside of an HTTP call.

Something similar to the below might suffice for the middleware.

using Finbuckle.MultiTenant;
using MassTransit;

namespace Finbuckle.MassTransit
{
    public class TenantIdSendFilter<T> : IFilter<SendContext<T>> where T : class
    {
        private readonly ITenantInfo _tenantInfo;

        public TenantIdSendFilter(ITenantInfo tenantInfo)
        {
            _tenantInfo = tenantInfo;
        }

        public async Task Send(SendContext<T> context, IPipe<SendContext<T>> next)
        {
            if (_tenantInfo != null)
            {
                context.Headers.Set("TenantId", _tenantInfo.Id);
            }

            await next.Send(context);
        }

        public void Probe(ProbeContext context)
        {
            context.CreateFilterScope("tenantIdSendFilter");
        }
    }

}

However I am unsure of the best way to implement a new strategy within Finbuckle as its not a web request and there is no authentication from an end user.

I plan on attempting to figure this out in the next few months.

[AndrewTriesToCode]

Hi @Bru456

I’m not an expert on MassTransit, but I think you will want to look at the TenantResolver class. It just takes a list of strategies and stores and processes through them for a match. Works well with DI and the Finbuckle configuration methods that add strategies and stores to DI.

It is barebones though, so take a look at the aspnetcore middleware if you want to see how the TenantResolver is used.

edit: the TenantResolver class is in the src/Finbuckle.MultiTenant core project.

[fbjerggaard]

I have made some filters that are used in production with MassTransit and FB.MultiTenant and it works pretty well:

https://gist.github.com/fbjerggaard/12c58f47c20cd4fd44e1ccae320110c8

It is sorta "hacky" in that I don't get Finbuckle to handle the strategy but do it manually, but it works pretty well.

It would be nice having it easily accessible in a package, however I am adding other things as well (that I removed from the samples) so not that useful to me.

[Bru456]

Excellent thank you @AndrewTriesToCode and @fbjerggaard, I'll have a play around with these and see what I can get working.

I'm currently intrested in only the identifier as each service should maintain the list of tenants from a central configuration store.

I feel a package for this would be very handy to have. I dont have indepth knowledge of how Finbuckle.MultiTenant works under the hood. But I am more than happy to look into a Finbuckle.MultiTenant.MassTransit capability.

[fbjerggaard]

I looked a bit into it, and I don't really see how we can utilize ITenantResolver without rewriting the current one.

I can't really see where the scope is created in MassTransit and how to hook into it. The closest I got currently is the following filter for the MassTransit middleware:

public class FinbuckleFilter<T, TTenantInfo>(IEnumerable<IMultiTenantStore<TTenantInfo>> stores) : IFilter<ConsumeContext<T>>
    where T : class
    where TTenantInfo : class, ITenantInfo, new()
{
    public Task Send(ConsumeContext<T> context, IPipe<ConsumeContext<T>> next)
    {
        // TODO: Look up tenant from store and set it.

        return next.Send(context);
    }

    public void Probe(ProbeContext context)
    {
        context.CreateScope("Finbuckle.MultiTenant");
    }
}

However, I don't know how to register this since it has 2 generic arguments where one of them (T) should be undefined to work for all message types and the other (TTenantInfo) needs to be specified.

[Bru456]

I think it will still require the developer to need to do some configuration.

I am seeing two possible ways to achieve this. I am unsure if this is correct.

The first way (Could be wrong on so many levels):

1. Create a new MassTransitHeader Strategy
2. Create an implementation WithMassTransitHeaderStrategy() in MultiTenantBuilderExtensions.cs to allow for tenant Resolution via dependency injection. I can see this working on a consume. Don't think this would work on a send or publish event tho. (I am unsure of this tbh. Not sure if its possible to get the context before its in the message.)
3. Create a series of MassTransit Pipeline Filters to allow developers To configure Send and Publish events.

The other possibly easier way:

1. Create a series of MassTransit Pipeline Filters to allow developers to configure Consume, Send and Publish events.
2. Document how to find the tenant within the message.

I have already created the ability to determine the tenant via a property in the message by taking the identifier and looking it up in the tenant store. using @fbjerggaard pipeline filter looks like a more streamlined approach. Dont suppose you can share a code snippet of how you can access the TenantInfo within a Consumer?

[fbjerggaard]

Dont suppose you can share a code snippet of how you can access the TenantInfo within a Consumer?

Right now I am just accessing it via the regular IMultiTenantContextAccessor<TTenantInfo> in my consumers.

Writing an extension on the ConsumeContext would probably be a great idea just as there is one on the HttpContext

I am unsure how to access the context during the strategy portion of FB.MT - During a quick test I did it didn't seem to try any of the strategies whenever a message was processed by MT.

I think the easiest solution would be to create a series of filters for setting and getting the TenantInfo and then maybe exposing a single UseMultiTenantFilters() on the MassTransit builder that takes care of all the configuration.

It just feels a bit hacky to completely go around the TenantResolver and strategies

[Bru456]

@fbjerggaard thanks, let me see what I can do. I might be completely wrong but I'm doing all the dev work here: https://github.com/Bru456/Finbuckle.MultiTenant branch will be called MassTransit just not pushed it up yet. I plan on building samples to play with too. Will be two Console applications for simplicity.

[Bru456]

@AndrewTriesToCode I am assuming that Finbuckle only supports ASP.Net?

I'm not seeing a middleware for console apps?

Does anyone here use console apps for their background services or do you always front them with ASP.Net Web APIs?

[Bru456]

@fbjerggaard Theres sadly no easy way to get the tenant via extending the ConsumeContext, there is no write options that I have found on the context to store anything. It is possible to create an extension to query the tenants and select the correct tenant each time. But if you have a lot of tenants and a lot of messages relying it on, it can become an expensive operation.

Its always an option tho :)

[AndrewTriesToCode]

No it works fine outside of ASP.NET Core. Works best with anything using the generic host which encapsulates DI behavior among other things—and can work just fine in console apps.

For example: https://dfederm.com/building-a-console-app-with-.net-generic-host/

the Finbuckle configuration will work on the services in that example. When you need to determine a tenant get ITenantResolver from DI to see who the current tenant is. The scope and context will be totally dependent on your situation outside of ASP.NET Core though.

[fbjerggaard]

@Bru456 I think the flow should be something like this:

• Action is performed by something that sets the MultiTenantContext
• Message is published using a PublishFilter that sets the tenantIdentifier header on the message based on the one in the context
• Message is consumed by the consumer which has a ConsumeFilter that is essentially a copy of the TenantResolver class except it doesn't have any strategy stuff and directly sets the tenantInfo using IMultiTenantContextSetter.

So something like this ConsumeFilter (Like the one I sent earlier, but expanded a bit with support for multiple stores etc.):

public class TenantConsumeFilter<T>(
    IMultiTenantContextSetter mtcs,
    IEnumerable<IMultiTenantStore<PlatformTenant>> stores,
    ILoggerFactory loggerFactory,
    IOptionsMonitor<MultiTenantOptions> options)
    : IFilter<ConsumeContext<T>>
    where T : class
{
    public void Probe(ProbeContext context)
    {
        context.CreateFilterScope("tenantConsumeFilter");
    }

    public async Task Send(ConsumeContext<T> context, IPipe<ConsumeContext<T>> next)
    {
        var mtc = new MultiTenantContext<PlatformTenant>();

        var identifier = context.Headers.Get<string>("tenantIdentifier");

        if (options.CurrentValue.IgnoredIdentifiers.Contains(identifier, StringComparer.OrdinalIgnoreCase))
        {
            (loggerFactory?.CreateLogger(GetType()) ?? NullLogger.Instance).LogInformation(
                "Ignored identifier: {Identifier}", identifier);
            identifier = null;
        }

        if (identifier is null)
        {
            await next.Send(context);
            return;
        }

        foreach (var store in stores)
        {
            var wrappedStore = new MultiTenantStoreWrapper<PlatformTenant>(store,
                loggerFactory?.CreateLogger(store.GetType()) ?? NullLogger.Instance);
            var tenantInfo = await wrappedStore.TryGetByIdentifierAsync(identifier);
            if (tenantInfo is null)
            {
                continue;
            }

            await options.CurrentValue.Events.OnTenantResolved(new TenantResolvedContext
            {
                Context = context,
                TenantInfo = tenantInfo,
                StrategyType = null,
                StoreType = store.GetType()
            });

            mtc.TenantInfo = tenantInfo;
            mtc.StrategyInfo = null; // TODO: Set when implemented in FB.MT package
            mtc.StoreInfo = null; // TODO: Set when implemented in FB.MT package
            mtcs.MultiTenantContext = mtc;

            await next.Send(context);
            return;
        }

        await options.CurrentValue.Events.OnTenantNotResolved(new TenantNotResolvedContext
            { Context = context, Identifier = identifier });

        await next.Send(context);
    }
}

These filters can then be registered by creating an extension method on the BusFactoryConfigurator in MassTransit:

    public static void AddTenantFilters(this IBusFactoryConfigurator configurator, IRegistrationContext context)
    {
        configurator.UseConsumeFilter(typeof(TenantConsumeFilter<>), context);
        configurator.UsePublishFilter(typeof(TenantPublishFilter<>), context);
        configurator.UseExecuteActivityFilter(typeof(TenantExecuteFilter<>), context);
        configurator.UseCompensateActivityFilter(typeof(TenantCompensateFilter<>), context);
        configurator.UseSendFilter(typeof(TenantSendFilter<>), context);
    }

I only have 1 problem with this right now - It is currently hardcoded to a specific ITenantInfo implementation (PlatformTenant) and I don't know enough about generics in C# to figure out how I can pass a generic TTenantInfo down to the filters while also preserving the generic nature of the message type.

[fbjerggaard]

@Bru456 I actually think I have something usable now. It became quite convoluted, but it seems to do its job.

It basically involves duplicating how MassTransit registers filters and customizing it to allow for a second generic type argument.

This ends up in the following snippet:

public static class MassTransitRegistrationExtensions
{
    public static void UseFinbuckleFilters<TTenantInfo>(this IBusFactoryConfigurator configurator,
        IRegistrationContext context)
        where TTenantInfo : class, ITenantInfo, new()
    {
        configurator.UseFinbuckleMultiTenantConsumeFilter<TTenantInfo>(context);
        configurator.UsePublishFilter(typeof(TenantPublishFilter<>), context);
        configurator.UseSendFilter(typeof(TenantSendFilter<>), context);
    }

    private static void UseFinbuckleMultiTenantConsumeFilter<TTenantInfo>(this IConsumePipeConfigurator configurator,
        IRegistrationContext context)
        where TTenantInfo : class, ITenantInfo, new()
    {
        var filterType = typeof(TenantConsumeFilter<,>);
        var messageTypeFilterConfigurator = new MessageTypeFilterConfigurator();
        var observer =
            new CustomScopedConsumePipeSpecificationObserver<TTenantInfo>(filterType, context,
                messageTypeFilterConfigurator.Filter);

        configurator.ConnectConsumerConfigurationObserver(observer);
        configurator.ConnectSagaConfigurationObserver(observer);
    }
}

I still need to create the PipeSpecificationObservers for Execute and Compensate

Which is then configured like this:

          mt.UsingRabbitMq((ctx, cfg) =>
            {   
[...]
            cfg.UseFinbuckleFilters<PlatformTenant>(ctx);
[...]
            });

The CustomScopedConsumePipeSpecificationObserver can be seen here: https://gist.github.com/fbjerggaard/0a64eb46e723850607cb70eea140540f

I still need to clean it up a bit - which will probably happen tomorrow. Then I can make a gist with all the required files so you/others can test it out and see if it works as intended.

It still skips all of the Finbuckle strategy stuff, but I just had a thought that it shouldn't be that hard to make a strategy that works for this - I just don't think it's needed since it is quite implicit the way it's configured.

[Bru456]

I wasnt even looking at the masstransit side. I've been attempting to do strategies.

I have this:

public class MassTransitHeaderStrategy : IMultiTenantStrategy
{
    private readonly string _headerKey;
    public MassTransitHeaderStrategy(string headerKey) 
    {
        _headerKey = headerKey;
    }

    public Task<string?> GetIdentifierAsync(object context)
    {
        string? header = null;

        if (!(context is ConsumeContext consumeContext))
            throw new MultiTenantException(null,
                new ArgumentException($"\"{nameof(context)}\" type must be of type ConsumeContext", nameof(context)));

        if (consumeContext.Headers.TryGetHeader(_headerKey, out var tenantId))
            {
                header = tenantId as string;
            }

        return Task.FromResult(header);
    }
}

I have been trying to figure out how to whack it into mass transit. and use the inbuilt IResolverBased on the strat resolution so everything just falls into place.

I have been struggling to get the tenant setup within a console app, even uses the static strat it still isnt picking it up....

current Program looks like this:

    public class Program
    {
        public static async Task Main(string[] args)
        {
            await CreateHostBuilder(args).Build().RunAsync();

            //Console.WriteLine("Hello, World!");

            Console.ReadLine();
        }

        public static IHostBuilder CreateHostBuilder(string[] args)

          => Host.CreateDefaultBuilder(args)
                .ConfigureServices((hostContext, services) =>
                {
                    services.AddMultiTenant<TenantInfo>()
                        .WithConfigurationStore()
                        //.WithInMemoryStore()
                        .WithStaticStrategy("tenant1")

                        .WithMassTransitHeaderStrategy("tenantIdentifier");

                    services.AddMassTransit(x =>
                    {
                        x.AddConsumer<GettingStartedConsumer>();
                        x.UsingInMemory((context, cfg) =>
                        {
                            //cfg.UseConsumeFilter(typeof(TenantConsumeFilter<>), context);
                            cfg.UsePublishFilter(typeof(TenantPublishFilter<>), context);
                            cfg.UseSendFilter(typeof(TenantPublishFilter<>), context);
                            cfg.ConfigureEndpoints(context);
                        });
                    });

                    services.AddHostedService<Worker>();
                });

    }
}

Think I'll move to a webapi as I know how to easily get that working.

[Bru456]

Okay, I am playing with the following strategy:

namespace Finbuckle.MultiTenant.MassTransit.Strategies
{
    public class MassTransitHeaderStrategy : IMultiTenantStrategy
    {
        private readonly string _headerKey;
        public MassTransitHeaderStrategy(string headerKey) 
        {
            _headerKey = headerKey;
        }

        public Task<string?> GetIdentifierAsync(object context)
        {
            string? header = null;

            if (!(context is ConsumeContext consumeContext))
                throw new MultiTenantException(null,
                    new ArgumentException($"\"{nameof(context)}\" type must be of type ConsumeContext", nameof(context)));

            if (consumeContext.Headers.TryGetHeader(_headerKey, out var tenantId))
                {
                    header = tenantId as string;
                }

            return Task.FromResult(header);
        }
    }
}

However I have noticed that the TenantResolver does not like it. It appears as tho the strategies, espically when using the Finbuckle.MultiTenant.AspNetCore results in errors being thrown when the strategy is not HttpContext however the resolver does not gracefully handle these and move to check the next strategy. It just continues to throw the error up the stack.

case in point BasePath:

namespace Finbuckle.MultiTenant.AspNetCore.Strategies;

public class BasePathStrategy : IMultiTenantStrategy
{
    public Task<string?> GetIdentifierAsync(object context)
    {
            if (!(context is HttpContext httpContext))
                throw new MultiTenantException(null,
                    new ArgumentException($"\"{nameof(context)}\" type must be of type HttpContext", nameof(context)));

           // removed for shortness
        }
}

@AndrewTriesToCode I can see the following way to address this:

Attempt to gracefully handle errors within TenantResolver.ResolveAsync by continuing on error with something like this:

public async Task<IMultiTenantContext<TTenantInfo>> ResolveAsync(object context)
{
  var mtc = new MultiTenantContext<TTenantInfo>();

  string? identifier = null;
  foreach (var strategy in Strategies)
  {
      //shorted for readability
      try{
          identifier = await wrappedStrategy.GetIdentifierAsync(context);
      }
      catch
      {
          continue;
      }
      //shorted for readability
  }
}

However this will no longer error out if its the wrong context types. I can still get it to error in the event they all error out. Thoughts???

This means the entire consumer filter becomes:

namespace Finbuckle.MultiTenant.MassTransit.MassTransitFilters
{
    public class TenantConsumeFilter<T> (
        ITenantResolver tenantResolver,
        IMultiTenantContextSetter mtcSetter
        ) 
        : IFilter<ConsumeContext<T>> 
        where T : class
    {

        public void Probe(ProbeContext context)
        {
            context.CreateFilterScope("tenantConsumeFilter");
        }

        public async Task Send(ConsumeContext<T> context, IPipe<ConsumeContext<T>> next)
        {
            IMultiTenantContext? multiTenantContext = await tenantResolver.ResolveAsync(context);
            mtcSetter.MultiTenantContext = multiTenantContext;

            await next.Send(context);
        }
    }
}

this would allow users to set the header with: .WithMassTransitHeaderStrategy("tenantIdentifier"); Just need to figure out how to get the header name to work on Send and publish events.

[fbjerggaard]

Maybe throwing an exception is not the right way to handle the wrong context type? Probably the "right" way to solve it is to rewrite the strategies to not throw exceptions for wrong context type but just return null and log a warning. This would enable support for all types of contexts.

Otherwise I really like your idea @Bru456 - Much simpler than what I cooked up.

It should also be possible to write an extension method on the ConsumeContext to get and set the MultiTenantContext via the payloads in MassTransit.

In regards to the header key, would it be a crazy idea to either:

• Provide it via IOptions
• Inject the strategy into the filter and expose the headerkey property through that

Personally I think the latter is the cleanest of those two.

[Bru456]

I was thinking that too with the rewriting the strategies, it feels better and less hacky. I doubt anyone does anything with them outside of Finbuckle.

I'm just not sure if it would have any unintended consequences. But hey thats what tests are for ;)

Why thank you @fbjerggaard, my goal was to keep it relying on already built functionality than trying to do anything "new" or duplicate it. So I was trying to replicate the middleware for ASP into the mass transit. Spent a lot of time trying to figure out how to get it via a AddMultiTenantMassTransit() approach, and just went nah, far easier adding it to MassTransit middleware filters instead. But, what you gave was a massive help and gave me new avenues to take :)

Funnily enough, I was thinking about the next task to see if its possible to inject the strategy, I might need to add a method to return the header. But keeps it clean :)

[fbjerggaard]

It made sense when Finbuckle only supported HttpContexts, but if additional types of contexts should be supported then throwing when it is an unsupported context type is probably not the way to go.

Another approach could be to define a (list?) of supported context types for each strategy and then filtering the strategies based on what the current context is before running them - That would maybe make for slightly more performant code since fewer checks for the same needs to happen, and then we could keep the throwing - although it would be redundant.

--

The only reason why I went the route I did was because it didn't seem like any strategies were actually tried when processing messages through MassTransit. But maybe something in my test was flawed, or I never really tried it :)

[fbjerggaard]

Also - @AndrewTriesToCode - Is this something you would want to have in the main repo here, or should the "interop" package rather live in its own repository?

It should definitely be its own project no matter what to avoid pulling in the MassTransit dependency for all users of this package, but whether it should be in this repository or its own is entirely up to you

[Bru456]

Could replace the object with the actual context types expected. i.e. HttpContext and ConsumeContext and possible have or modify the factory to intelligently route to the correct context types. and if a strategy supports more than one context type, overload it to the correct one?

But I dont really wanna modify the main one in any meaningful way without @AndrewTriesToCode say so.

I'm close to pushing what I have: I have added:

• new sample sample/net8.0/MassTrainsitApi
• new class library src/Finbuckle.MultiTenant.MassTransit <- all of my work is here
• Modified the TenantResolver to not fail on wrong context in src/Finbuckle.MultiTenant

Still to do:

• Docs
• tests
• Readme for the sample

I should be committing my stuff tonight as its in a somewhat useable state to here: https://github.com/Bru456/Finbuckle.MultiTenant

[Bru456]

Successful test complete: Log Entries for both a producer and consumer: MassTransitApi.Controllers.TestBusController: Information: Sending Bus Message for Tenant: tenant-1

MassTransitApi.Consumers.GettingStartedConsumer: Information: Tenant: tenant-1 Received: Hello, World!

[Bru456]

Pushed into here:

https://github.com/Bru456/Finbuckle.MultiTenant/tree/MassTransit

Please check it out.

1. Set the startup project to: samples/net8.0/MassTransitApi hit play.
2. In a Postman or something similar. a. Send a GET request to https://localhost:<<YourPort>>/TestBus b. include header key: tenant value: tenant-1, tenant-2 or tenant-3 (I have not tested with an invalid tenant btw)
3. watch the logs

[Bru456]

Still to be done:

To be Complete:

• [x] TenantConsumerFilter
• [x] TenantPublishFilter
• [x] TenantSendFilter
• [x] TenantExecuteFilter
• [x] TenantCompensateFilter
• [ ] Create End User Documentation
• [ ] Create Unit Tests
• [ ] Readme in the MassTransit Section
• [ ] Readme in the Sample App.
• [x] Make TenantResolver and/or strategies work with more than just http context
• [ ] @AndrewTriesToCode approval

[fbjerggaard]

Looking good so far!

Some quick notes:

• The Execute and Compensate filters are basically just be copies of the Consume filter
• I think it would be a good idea to create an extension method on the IBusFactoryConfigurator to register the needed filters to avoid having the users manually registering all the filters.
• Any specific reason you created your own ConstantsExtensions.MassTransitTenantHeader instead of just using TenantToken?
• Maybe there should be some checks that the masstransit header strategy is actually registered if the filters are added? I don't know where to put these checks though, but I can see it being a potential issue.

[Bru456]

Thanks @fbjerggaard

• The Execute and Compensate filters are basically just be copies of the Consume filter

Thank you, should make it easy.

• I think it would be a good idea to create an extension method on the IBusFactoryConfigurator to register the needed filters to avoid having the users manually registering all the filters.

Possibly, is there a use case to have this blanket on? Would need to test to ensure that a blanket on wont impact if there is no tenant. Right now its configurable down to individual topics/queues. There might be a slight impact to performance with a blanket on.

• Any specific reason you created your own ConstantsExtensions.MassTransitTenantHeader instead of just using TenantToken

I think, this is just a remnant of me stumbling around trying to figure it out :D Edit: Constants within Finbuckle.MultiTenant is internal and not accessible. Edit 2: I have made the internals visible to it.

• Maybe there should be some checks that the masstransit header strategy is actually registered if the filters are added? I don't know where to put these checks though, but I can see it being a potential issue.

Any ideas on how to achieve this?

[fbjerggaard]

Possibly, is there a use case to have this blanket on? Would need to test to ensure that a blanket on wont impact if there is no tenant. Right now its configurable down to individual topics/queues. There might be a slight impact to performance with a blanket on.

For example in my usecase - I am not doing anything that is not related to a tenant, so therefore I need the tenantIdentifier set on absolutely everything that goes throug MassTransit. It should be pretty easy to make two extension methods - one configurable per message type/topic/queue and one that is blanket on.

Any ideas on how to achieve this?

Not really sorry. The only thing I could come up with is checking in the filters, but that seems like a heavy operation to do on each message.

[Bru456]

@fbjerggaard Do you actively use the Execute and Compensate contexts?

https://masstransit.io/documentation/concepts/messages#message-headers this says:

Message headers can be read using the ConsumeContext interface and specified using the SendContext interface.

[Bru456]

Looking at TenantResolver MultiTenantStrategyWrapper and some of the strategies.

I think we can safely change the throw an error to simply return null.

TenantResolver has a specific area that says if identifier == null then continue

Thus if no strategy finds it, it simply carries on with its life as normal if it cant find the tenant in the configured strategies.

And more importantly requires no change to the TenantResolver just the strategies.

[Bru456]

@AndrewTriesToCode I can see from the git history that the strategies have always been set to throw an error.

Would this have any unintended issues if it was changed to return null instead?

[fbjerggaard]

@fbjerggaard Do you actively use the Execute and Compensate contexts?

Yes - when using Routing slips the context differs and is then either a Execute or Compensate context. So actually, the strategy needs to be able to handle multiple different context types now that I think about it. Unless they can be mapped to a ConsumeContext since the ExecuteContext inherits from CourierContext which then inherits from ConsumeContext<RoutingSlip> - That would probably require some testing.

[Bru456]

@fbjerggaard 5 steps ahead of you ;)

public Task<string?> GetIdentifierAsync(object context)
{
    string? header = null;

    if (!(context is ConsumeContext || context is CompensateContext || context is ExecuteContext))
        return Task.FromResult<string?>(null);

    if(context is MessageContext messageContext)
    {
        if (messageContext.Headers.TryGetHeader(_config.TenantIdentifierHeaderKey, out var tenantId))
        {
            header = tenantId as string;
        }
    }

    //if (consumeContext.Headers.TryGetHeader(_config.TenantIdentifierHeaderKey, out var tenantId))
    //    {
    //        header = tenantId as string;
    //    }

    return Task.FromResult(header);
}

[Bru456]

@fbjerggaard any idea how to unit test the filters?

Only thing I can think of is to:

1. Create a multi tenant config
2. Create an in memory mass transit test harness with the filters applied
3. run test messages through it

Dont get me wrong, this would defo ensure it works :D just wondering if you have done any testing of your filters in isolation?

[fbjerggaard]

I haven't done any unit testing on my filters in isolation (Or at all, actually.. :smile: ) But it seems like a reasonable approach to do it, and would probably be the way I would do it too.

[AndrewTriesToCode]

@Bru456 The strategies in the Finbuckle.MultiTenant.AspNetCore package do throw an error if the context isn't HttpContext by design, but those in Finbuckle.MultiTenant don't. I would be supportive of the change to the wrapper that null context isn't an error but rather just returns null. I think technically it would be a breaking change but very unlikely to impact anyone.

Also I'm thrilled to see the engagement on this issue with you both--I should learn MassTransit!

Regarding a pull request -- I want to keep the official repo as universal as possible. Something more specialized like this would be better in its own repo. If you wanted to create one I'd be happy to link to it from the readme and the website.

[Bru456]

Thanks @AndrewTriesToCode, its currently built to be slotted next to your stuff. I.e. I some of the internals of Finbuckle.MultiTenant currently thats just the constants. I have also modified the AspNetCore strategies to do this in my version:

public Task<string?> GetIdentifierAsync(object context)
{
    if (!(context is HttpContext httpContext))
        return Task.FromResult<string?>(null);
        //throw new MultiTenantException(null,
        //    new ArgumentException($"\"{nameof(context)}\" type must be of type HttpContext", nameof(context)));

    return Task.FromResult(httpContext?.Request.Headers[_headerKey].FirstOrDefault());
}

So far all this has done is brake the unit tests expecting an error instead of null. Everything else is working fine - as far as I can tell.

Currently fighting with unit tests trying to test the filters 😄

All work is being done here: https://github.com/Bru456/Finbuckle.MultiTenant/tree/MassTransit.

Once I get the unit tests working I'll do another push.

[Bru456]

Pushed latest with unit tests:

https://github.com/Bru456/Finbuckle.MultiTenant/tree/MassTransit.

@fbjerggaard can you provide examples of Execute and Compensate please. I have not used them so no idea what they look like.

Unit tests for Publish and Send (Consume is baked into them) is working and passing.

I have also changed all the exceptions for not being HttpContext to return null in Finbuckle.MultiTenant.AspNetCore

I have also modified (commented out and recreated) those unit tests to be check for nulls.

All Tests passing.

I have not added .net6 or .net7 support. Should only be package details so nothing too major.

Inside of Finbuckle.MultiTenant.MassTransit.Test.MassTransitFilters.MultiTenantMassTransitTestSetup.cs This will create a service provider, and MassTransit Test Harness. I think then config multi tenant services with the WithMassTransitHeaderStrategy and an In memory store of 3 tenants.

I then configure the Test harness to use a consumer (created in a class just below in the same file) and use the in memory bus and configured all of the filters on the bus.

I then use this in the tests to create the test environment and manually set the MultiTenantContext to the specified tenant and check for the corresponding headers to be present in the messages in both the Producer and Consumer.

I have not created the auto injector thing that @fbjerggaard wants as well I am kinda scared to learn the internals of Mass Transit.... But feel free to give it a bash :D

[Bru456]

surprisingly painless to add .net6 and .net7 support MassTransit is .net standard 2.0 so anything .net5+ supports it:

[Bru456]

@fbjerggaard added the IBusFactoryConfigurator extension method. Didn't realise you did it already.

Tested it, works fine.

                // This is a single add command that can be used to apply all FinBuckle.MultiTenant filters to the MassTransit pipeline.
                x.UsingInMemory((IBusRegistrationContext context, IInMemoryBusFactoryConfigurator cfg) => //using in memory for simplicity. Please replace with your preferred transport method.
                {
                    cfg.AddTenantFilters(context); // Required if wanting to have a MassTransit Consumer and maintain tenant context. To use this filter, .WithMassTransitHeaderStrategy() must be called in the MultiTenantBuilder.
                    cfg.ConfigureEndpoints(context);
                });

Unit tests added to test both individual filter commands and adding all via AddTenantFilters

Just have docs left to go. and the Execute and Compensate.

@fbjerggaard can you provide examples of Execute and Compensate please. I have not used them so no idea what they look like.

@AndrewTriesToCode Regarding:

Regarding a pull request -- I want to keep the official repo as universal as possible. Something more specialized like this would be better in its own repo. If you wanted to create one I'd be happy to link to it from the readme and the website.

I would like to keep it under Finbuckle if at all possible (mostly for the name and so people know its associated.) That being said if you still want it separate can you create a new repo under the Finbuckle org for it please. We will need to make some changes in the main repo to accommodate it. Espically if people want both ASP.Net and Mass Transit, which I do... 😉

I have also seen a fair bit of chatter over in Mass Transit to get this to work as well. Some figured it out, some implemented in their solutions. I feel this is a good thing to keep them reasonably close.

• https://github.com/MassTransit/MassTransit/discussions/2410

[fbjerggaard]

@fbjerggaard can you provide examples of Execute and Compensate please. I have not used them so no idea what they look like.

Yep, i'll cook something up on monday when i'm back in the office with easier access to the codebase using it :)

[Bru456]

@fbjerggaard dont suppose you had a chance?

[Bru456]

Also anyone think there is scope for a WithMassTransitBodyStrategy?

I think yes, but from looking at it, seems possible only with a ConsumeContext and not the others. So my thoughts is a maybe...

Might be easier and more fool proof just doing docs to say how it find the tenant from the store based on the identifier as I cant modify the body in the filters.

[fbjerggaard]

@fbjerggaard dont suppose you had a chance?

Sorry, got hung op on actual work yesterday. Tried forking your repository but couldn't do it because I already have a fork, so heres a link to a gist with the unit test for execute/compensate:

https://gist.github.com/fbjerggaard/3507af0fb09e8fe4aea40f87b78198e5

[Bru456]

@fbjerggaard thank you! Added :)

Just have user docs to create now.

@AndrewTriesToCode have you had a chance to see the below?

@AndrewTriesToCode Regarding:

Regarding a pull request -- I want to keep the official repo as universal as possible. Something more specialized like this would be better in its own repo. If you wanted to create one I'd be happy to link to it from the readme and the website.

I would like to keep it under Finbuckle if at all possible (mostly for the name and so people know its associated.) That being said if you still want it separate can you create a new repo under the Finbuckle org for it please. We will need to make some changes in the main repo to accommodate it. Espically if people want both ASP.Net and Mass Transit, which I do... 😉

[Bru456]

Okay I have encountered an issue after attempting to integrate into my own project....

I have a custom tenantinfo lets call it CustomTenantInfo : TenantInfo or CustomTenantInfo : ITenantInfo neither work tbh

I get the following error back from the Bus and it is in faulted state.

Message = "Unable to resolve service for type 'Finbuckle.MultiTenant.Abstractions.IMultiTenantContext' while attempting to activate 'Finbuckle.MultiTenant.MassTransit.MassTransitFilters.TenantPublishFilter`1[SharedModels.Contracts.IGetDataRepoIntegration]'."

This is because I am using CustomTenantInfo which is being created during DI time and my publish filter is looking for TenantInfo which it cant find during the DI.

If I use TenantInfo instead of CustomTenantInfo it works, but my authentication fails because of missing OAuth from the store.

This is because I am using in the filter with DI IMultiTenantContextAccessor<TenantInfo> mtca now If I use IMultiTenantContextAccessor<ITenantInfo> mtca I get a compile time error due to no paramless constructor.

Any ideas around this guys?

I have looked at adding TTenantInfo but this requires a lot more changes to the MassTransit side. and that is a far bigger project that I'm currently willing to do.

[fbjerggaard]

@Bru456 What if you just access the plain IMultiTenantContextAccessor without the generic type?

[Bru456]

.................

I both hate you and love you right now :D

unit tests are passing, and the message is being sent.

Swear I tried that.... then again it was nearly midnight and I was at it from 9 am....

[Bru456]

pushed it up.

At a reasonably good state. just need to figure out where we are putting it before I do the docs.

[AndrewTriesToCode]

Thanks again gentlemen.

I think I will make another repo under the org for Finbuckle.MultiTenant.MassTransit

My only request would be that you provide enough detail in the readme that it be reasonably usable by others and provide a license and disclaimer that no support is provided.

Also I don’t plan on publishing a nuget for it for now.

Does that work for you?

[Bru456]

@AndrewTriesToCode sure, will need to make some changes so it sits outside of it.

Main changes that will need to be made:

1. Finbuckle.MultiTenant.EntityFrameworkCore the following will need to be modified to return null instead of throw an error. I have this done already so expect a PR from me. a. BasePathStrategy b. ClaimStrategy c. HeaderStrategy d. HostStrategy e. RemoteAuthenticationCallbackStrategy f. RouteStrategy g. SessionStrategy
2. Finbuckle.MultiTenant Constants will need to be made public to accommodate the need to access it from outside the assembly. I am unsure simply adding it to AssemblyInfo is sufficient espically if its in a different repo.

I'll host the docs within the repo and read me. If we decide to take it further and add it to Nuget we can put the docs in the finbuckle website :)

[Bru456]

Added the readme:

https://github.com/Bru456/Finbuckle.MultiTenant/blob/MassTransit/src/Finbuckle.MultiTenant.MassTransit/README.md

Once the repo is created I'll fork it and move it over there :)