Code snippets showing the initialization of MassTransit locally (RabbitMQ) or in the cloud (Azure Service Bus) based on configuration

CreateServiceBus.cs

// IComponentContext from Autofac, using DI container to create message consumers
public static IBusControl Create(IComponentContext componentContext)
{
    var serviceBusConfiguration = GetServiceBusConfiguration();    
    var serviceBus = CreateServiceBus(serviceBusConfiguration, componentContext);
    await serviceBus.StartAsync();
    return serviceBus;
}

ExampleEndpoints.cs

private static void ConfigureReceiveEndpoint(
    IReceiveEndpointConfigurator configurator,
    IComponentContext componentContext)
{
    configurator.Consumer(componentContext.Resolve<Func<Message1Consumer>>());
    configurator.Consumer(componentContext.Resolve<Func<Message2onsumer>>());
}

MassTransitConfiguration.cs

private static ServiceBusConfiguration GetServiceBusConfiguration()
{
    switch (AppConfiguration.ServiceBusTransport)
    {
        case ServiceBusTransport.RabbitMq:
            return GetRabbitMqConfiguration();
        case ServiceBusTransport.AzureServiceBus:
            return GetAzureServiceBusConfiguration();
        case ServiceBusTransport.NullBus:
            return GetNullBusConfiguration();
        default:
            throw new ArgumentOutOfRangeException("Service bus transport not configured.");
    }
}

private static ServiceBusConfiguration GetRabbitMqConfiguration()
{
    return new ServiceBusConfiguration
    {
        Transport = ServiceBusTransport.RabbitMq,
        HostUri = new Uri($"{AppConfiguration.RabbitMqHostUri}/{AppConfiguration.RabbitMqVirtualHostName}"),
        QueueName = $"app.{AppConfiguration.AppEnvironment}"
    };
}

private static ServiceBusConfiguration GetAzureServiceBusConfiguration()
{
    return new ServiceBusConfiguration
    {
        Transport = ServiceBusTransport.AzureServiceBus,
        HostUri = ServiceBusEnvironment.CreateServiceUri(
            AppConfiguration.AzureServiceBusScheme,
            AppConfiguration.AzureServiceBusNamespace,
            AppConfiguration.AzureServiceBusPath),
        QueueName = $"app.{AppConfiguration.AppEnvironment}"
    };
}

private static ServiceBusConfiguration GetNullBusConfiguration()
{
    return new ServiceBusConfiguration
    {
        Transport = ServiceBusTransport.NullBus,
        HostUri = new Uri("http://null"),
        QueueName = $"app.{AppConfiguration.AppEnvironment}"
    };
}

MassTransitCreate.cs

private static IBusControl CreateServiceBus(
    ServiceBusConfiguration configuration,
    IComponentContext componentContext)
{
    switch (configuration.Transport)
    {
        case ServiceBusTransport.RabbitMq:
            return CreateRabbitMqServiceBus(configuration, componentContext);
        case ServiceBusTransport.AzureServiceBus:
            return CreateAzureServiceBus(configuration, componentContext);
        case ServiceBusTransport.NullBus:
            return CreateNullBus(configuration, componentContext);
        default:
            throw new ArgumentOutOfRangeException("Service bus transport not configured.", new Exception());
    }
}

private static IBusControl CreateRabbitMqServiceBus(
    ServiceBusConfiguration configuration,
    IComponentContext componentContext)
{
    return Bus.Factory.CreateUsingRabbitMq(
        c =>
        {
            c.UseSerilog();

            var host = c.Host(
                configuration.HostUri,
                conf =>
                {
                    conf.Username(AppConfiguration.RabbitMqVirtualHostUsername);
                    conf.Password(AppConfiguration.RabbitMqVirtualHostPassword);
                });

            c.ReceiveEndpoint(
                host,
                configuration.QueueName,
                conf => ConfigureReceiveEndpoint(conf, componentContext));
        });
}

private static IBusControl CreateAzureServiceBus(
    ServiceBusConfiguration configuration,
    IComponentContext componentContext)
{
    return Bus.Factory.CreateUsingAzureServiceBus(
        c =>
        {
            c.UseSerilog();

            var tokenProvider =
                TokenProvider.CreateSharedAccessSignatureTokenProvider(
                    AppConfiguration.AzureServiceBusKeyName,
                    AppConfiguration.AzureServiceBusKey);

            var host = c.Host(
                configuration.HostUri,
                conf => { conf.TokenProvider = tokenProvider; });

            c.ReceiveEndpoint(
                host,
                configuration.QueueName,
                conf => ConfigureReceiveEndpoint(conf, componentContext));
        });
}

private static IBusControl CreateNullBus(
    ServiceBusConfiguration configuration,
    IComponentContext componentContext)
{
    return Bus.Factory.CreateUsingInMemory(
        c =>
        {
            c.ReceiveEndpoint(
                configuration.QueueName,
                ep => { ConfigureReceiveEndpoint(ep, componentContext); });
        });
}

ServiceBusConfiguration.cs

class ServiceBusConfiguration
{
    public ServiceBusTransport Transport { get; set; }
    public Uri HostUri { get; set; }
    public string QueueName { get; set; }
}