ITenantPropagationAdapter interface

Namespace: Tenantry.Pro · Package: Tenantry.Pro · API reference

An extension point: for code that extends the package, such as another package that builds on it. An application rarely needs it.

A tenant-propagation adapter for a job or messaging library: what the startup check needs to know of it. Tenantry.Pro's Hangfire, MassTransit, Quartz.NET and Rebus integrations implement it, and so can an adapter of your own for another library. Register it with TenantPropagationAdapter.Add<TKey, TAdapter>, which gives it its TenantPropagationOptions, the propagator, and the startup check.

An adapter has two sides. Its registration, a pro.Add…Propagation() method, calls TenantPropagationAdapter.Add<TKey, TAdapter>. Its host side, a UseTenantry method on the library's configuration, resolves TenantPropagationIntegration<TAdapter>, calls TenantPropagationIntegration<TAdapter>.MarkWired, and adds the library's filters, which carry the tenant with its TenantPropagationIntegration<TAdapter>.Propagator and TenantPropagationIntegration<TAdapter>.Options.

Once every hosted service has started, the startup check fails the host with InvalidOperationException if the host side has not run, since the jobs or messages would then carry no tenant. The message names ITenantPropagationAdapter.Registration and asks for ITenantPropagationAdapter.HostSide, or says what ITenantPropagationAdapter.FindUnwired returns. The check waits up to five seconds for a host side that runs on the thread pool after the host has started, as a library that configures itself in a BackgroundService does.

It is registered as a singleton, and created as the host starts.

internal sealed class KafkaPropagation : ITenantPropagationAdapter
{
    public string Registration => "pro.AddKafkaPropagation()";
    public string HostSide => "call consumer.UseTenantry(sp) on each Kafka consumer";
}

[EditorBrowsable(EditorBrowsableState.Advanced)]
public interface ITenantPropagationAdapter

PropertiesCopy Anchor Link

HostSideCopy Anchor Link

The host-side call the startup error asks for, with an example, such as call consumer.UseTenantry(sp) on each Kafka consumer.

string HostSide { get; }

Value: string

RegistrationCopy Anchor Link

The registration that added the adapter, for the startup error, such as pro.AddKafkaPropagation().

string Registration { get; }

Value: string

MethodsCopy Anchor Link

FindUnwired(IServiceProvider, int)Copy Anchor Link

Returns what is not wired, for the startup error, when the host side has run, but not for everything that needs it: for a library that can have several buses, each configured on its own. Returns null to leave it to the check's own rule, that the host side must have run at least once; that is the default.

string? FindUnwired(IServiceProvider services, int wiredCount)

Parameters:

• services IServiceProvider: The application's services.
• wiredCount int: How many times the host side has run (TenantPropagationIntegration<TAdapter>.WiredCount).

Returns: string: What is not wired, as a sentence that ends with a full stop, or null.

public string? FindUnwired(IServiceProvider services, int wiredCount)
{
    var consumers = services.GetServices<IKafkaConsumer>().Count();
    return wiredCount >= consumers ? null : $"Only {wiredCount} of {consumers} Kafka consumers call consumer.UseTenantry(sp).";
}

RunDeferredHostConfiguration(IServiceProvider)Copy Anchor Link

Runs host configuration that the library defers until one of its services is first resolved, so the startup check sees a host side that runs there. The check calls it once, before it waits, when the host side has not run for everything that needs it. By default it does nothing.

void RunDeferredHostConfiguration(IServiceProvider services)

Parameters:

• services IServiceProvider: The application's services.

Only resolve configuration that starts nothing: a job server or a bus must not start here.