Running hosted service inside module's DI container

[bojanz27]

Hi,

Is there any advice on how to run a hosted service inside a module?

This repo does not seem to give any example of how to properly use a hosted service inside of a module.

For context:

MassTransit will by default register a hosted service. If we do register MassTransit inside a module's own container, this hosted service is never started as the module is not actually plugged into the Host's startup (host.Run()).

The idea I'm currently working around is using IHostApplicationLifetime as an input for the module Initialization method. Something along the lines:

ShipmentsModuleStartup.Initialize(config =>
{
    config.Configuration = host.Services.GetRequiredService<IConfiguration>();
    config.HostApplicationLifetime = host.Services.GetService<IHostApplicationLifetime>();
    config.RegisterRabbitMqConsumers = true;
});

And, inside the module, hook into host's ApplicationStarted:

public static void Initialize(Action<ModuleConfiguration> configure)
{
    var configuration = new ModuleConfiguration();

    configure(configuration);

    if (configuration.Configuration is null)
    {
        throw new ModuleInitializationException("Configuration is null");
    }

    var logger = GetModuleInitializationLogger(configuration.Configuration);

    logger.Information("Initializing module Shipments");

    var container = CompositionRoot.BuildContainer(configuration.Configuration, configuration.RegisterRabbitMqConsumers);

    if (configuration.HostApplicationLifetime != null)
    {
        StartHostedServices(container, configuration.HostApplicationLifetime);
    }
}

private static void StartHostedServices(IContainer container, IHostApplicationLifetime hostApplicationLifetime)
{
    var hostedServices = container.Resolve<IEnumerable<IHostedService>>();

    foreach (var hostedService in hostedServices)
    {
        hostApplicationLifetime.ApplicationStarted.Register(() => hostedService.StartAsync(new CancellationToken()).GetAwaiter().GetResult());
    }
}

I'm wondering has anyone had a similar problem, and what was their approach?