Polybus

Polybus is a lightweight language-agnostic Event Bus for communication between microservice in asynchronous mode. Even though this repository is C# but the concept can be apply to other languages. Thus, enabled service communication written in different language.

Using

First, install the implementation for the message broker you want to use:

• RabbitMQ

It is recommended to integrate Grpc.Tools to the project to enable automatic compilation of .proto files by adding the following to .csproj:

  <ItemGroup>
    <PackageReference Include="Grpc.Tools" Version="2.32.0">
      <PrivateAssets>all</PrivateAssets>
      <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
    </PackageReference>
  </ItemGroup>

  <ItemGroup>
    <Protobuf Include="**/*.proto" GrpcServices="None"/>
  </ItemGroup>

Publishing event

You need to construct an instance of IEventPublisher implementation, which is depend on the message broker you use (e.g. Polybus.RabbitMQ.EventPublisher for RabbitMQ). If you are using Microsoft Dependency Injection framework you can use extension method of IServiceCollection provided by each implementation to register IEventPublisher automatically. e.g.:

services.AddRabbitMQConnection(new ConnectionFactory()
{
    DispatchConsumersAsync = true, // This field is required.
    // Populate other connection information.
});

services.ConfigureRabbitMQEventBus(options =>
{
    // Populate properties of options.
});

services.AddRabbitMQPublisher();

Consuming event

Consuming event is depend on message broker you are using. But usually you will need to construct the class that implemented IEventListener (e.g. Polybus.RabbitMQ.EventListener for RabbitMQ) and passed the implementation of IEventConsumer<T> to it. Once everything are ready you can invoke StartAsync on the event listener to start consuming.

Usually there will be extensions method for Microsoft Dependency Injection like publishing event for each implementation.

Development

Prerequisites

• .NET Core 3.1
• Protocol Buffer Compiler
• Docker Compose

Build

dotnet build src/Polybus.sln

Running tests

First you need to start the required services with Docker Compose:

docker-compose up -d

Then run all tests with:

dotnet test src/Polybus.sln