RockyBus

A .NET Standard message bus library that is extensible for simple needs.

Getting Started

See demo project for a working example (with missing configuration).

Messaging

There are two types of message that are supported, events and commands. For details or understanding, NServiceBus does a great job at explaining it here: https://docs.particular.net/nservicebus/messaging/messages-events-commands.

Publishing an event

await bus.Publish(new UserCreated());

Sending a command

await bus.Send(new Email());

Handling a message

1. Create a message handler class that implements IMessageHandler<T> where T is the command or event class.
2. Register the message handler directly to RockyBus or using a DI framework.

//Directly to RockyBus
new BusBuilder().AddMessageHandler(() => new RottenAppleCommandHandler());

//Using Microsoft Dependency Injection
new BusBuilder().UseMicrosoftDependencyInjection(p, serviceCollection);

3. Define a unique queue name for the handling service that does not conflict with another purpose handling service.

//Azure Service Bus
new BusBuilder()
    .UseAzureServiceBus(
        ConnectionString,
        configuration =>
        {
            configuration.ReceiveOptions.QueueName = "saturn";
        });

Running the bus

Help the bus find the messages and start the bus.

var bus = new BusBuilder()
    .DefineCommandScanRuleWith(t => t.Namespace == "RockyBus.DemoMessages" && t.Name.EndsWith("Command"))
    .DefineEventScanRuleWith(t => t.Namespace == "RockyBus.DemoMessages" && t.Name.EndsWith("Event"))
    .Build();
await bus.Start();

Configuring to allow RockyBus to manage the service bus resource

1. Azure Portal

   1. Create an AAD application.
   2. In the resource group or subscription -> Access control (IAM), add the AAD application as a contributor role.

2. Getting values

   • Subscription ID - can be found on the service bus resource's Overview
   • Resource Group Name - can be found on the service bus resource's Overview
   • Namespace Name - this is the service bus resource name
   • Directory (tenant) ID - can be found on the AAD's application (app that is registered)
   • Application (client) ID - can be found on the AAD's application (app that is registered)
   • Client Secret - can be generated in AAD's application (app that is registered) under Certificates & secrets
   • ConnectionString (used for sending and listening to messages) - can use the RootManageSharedAccessKey in the service bus resource's Shared access policy menu.

3. Setting values

new BusBuilder()
    .UseAzureServiceBus(
        ConnectionString,
        configuration =>
        {
            configuration.SetManagementSettings(SubscriptionId, TenantId, ClientId, ClientSecret, ResourceGroupName, NamespaceName);
        });

Resources

https://docs.microsoft.com/en-us/azure/active-directory/develop/howto-create-service-principal-portal https://docs.microsoft.com/en-us/azure/active-directory/develop/quickstart-register-app

Why?

• Projects getting into event based architecture may have a harder time justifying NServiceBus and want to get started. Should be easy refactor and transition to NServiceBus when the time is right.
• More simple projects that only requires simple, common messaging patterns.

Supported Message Transports

• Azure Service Bus - https://github.com/Azure-Samples/service-bus-dotnet-management

Supported Patterns

• PubSub Pattern
• Command Message

Supported Dependency Injection Frameworks

• Microsoft.Extensions.DependencyInjection

Supported .NET Versions

• .NET Core 2.0
• ??

Feel free to reach out to contribute.