Brighter V10: Using PostgreSQL as a Lightweight Messaging Gateway

In previous articles, I covered Brighter V10 RC1. One notable addition is support for Postgres as a messaging gateway, ideal for small applications or prototypes due to its simplicity and lightweight setup.

Requirement

• .NET 8 or superior
• A .NET project with these NuGet packages
  • Paramore.Brighter.MessagingGateway.Postgres: Enables Postgres integration for message queuing.
  • Paramore.Brighter.ServiceActivator.Extensions.DependencyInjection: Enable register Brighter with Microsoft DI.
  • Paramore.Brighter.ServiceActivator.Extensions.Hosting: Hosts Brighter as a background service.
  • Serilog.AspNetCore: For structured logging (optional but recommended).

Brighter Recap

Before continuing about Postgres configuration, let's recap what we already know about Brighter.

Request (Command/Event)

Define messages using IRequest:

public class Greeting() : Event(Guid.NewGuid())
{
    public string Name { get; set; } = string.Empty;
}

• Commands: Single-recipient operations (e.g., SendEmail).
• Events: Broadcast notifications (e.g., OrderShipped).

Message Mapper (Optional)

Translates between Brighter messages and your app objects, by default Brighter will use JSON serialize.

Request Handler

Processes incoming messages:

public class GreetingHandler(ILogger<GreetingHandler> logger) : RequestHandler<Greeting>
{
    public override Greeting Handle(Greeting command)
    {
        logger.LogInformation("Hello {Name}", command.Name);
        return base.Handle(command);
    }
}

Configuring Brighter with Postgres

1. Connection Setup

Define Postgres connection details:

var config = new RelationalDatabaseConfiguration(
  "<connection-string>", 
   queueStoreTable: "QueueData" // Auto-created if missing
);

Note: If the queue table doesn't exist, Brighter will create it automatically

2. Postgres Subscription

Subscribe to a topic:

 .AddServiceActivator(opt =>
 {
     opt.Subscriptions =
     [
         new PostgresSubscription<Greeting>(
             subscriptionName: new SubscriptionName("greeting.subscription"),
             channelName: new ChannelName("greeting.topic"),
             makeChannels: OnMissingChannel.Create,
             messagePumpType: MessagePumpType.Reactor,
             timeOut:  TimeSpan.FromSeconds(10)
           ),
     ];

     opt.DefaultChannelFactory = new PostgresChannelFactory(new PostgresMessagingGatewayConnection(config));
})

3. Postgres Producer Configuration

Publish events to a topic:

.UseExternalBus(opt =>
{
    opt.ProducerRegistry = new PostgresMessagingGatewayConnection(config, [
        new PostgresPublication<Greeting>
        {
            Topic = new RoutingKey("greeting.topic"),
            MakeChannels = OnMissingChannel.Create
        }]).Create();
})

Conclusion

Integrating Brighter with Postgres simplifies building scalable, message-driven systems for lightweight use cases. By leveraging V10’s improved defaults and Postgres’ reliability, developers can focus on business logic without the overhead of complex infrastructure.

Key Benefits

• Transactional consistency: Leverage Postgres' ACID guarantees
• Simplified infrastructure: Single database for app data + messaging
• Rapid prototyping: Eliminate dedicated message broker dependencies

Note: For production workloads requiring high throughput, consider dedicated brokers like Kafka or RabbitMQ.

For a complete working example, refer to the GitHub sample repository.