NestJS Redis Messaging Extension

@nestjstools/messaging-redis-extension

A powerful Redis messaging extension for NestJS built on top of @nestjstools/messaging.

This library enables asynchronous and synchronous messaging, supporting:

• Message buses
• Channels
• Consumers
• Distributed communication
• Scalable microservices architecture

It helps you build decoupled, event-driven, and production-ready NestJS applications using Redis as a transport layer.

Documentation

• https://docs.nestjstools.com/messaging
• https://nestjstools.com

Installation

npm install @nestjstools/messaging @nestjstools/messaging-redis-extension 

or

yarn add @nestjstools/messaging @nestjstools/messaging-redis-extension

Redis Integration: Messaging Configuration Example

import {MessagingModule} from '@nestjstools/messaging';
import {SendMessageHandler} from './handlers/send-message.handler';
import {MessagingRedisExtensionModule, RedisChannelConfig} from '@nestjstools/messaging-redis-extension';

@Module({
   imports: [
      MessagingRedisExtensionModule,
      MessagingModule.forRoot({
         buses: [
            {
               name: 'message.bus',
               channels: ['my-channel'],
            },
            {
               name: 'command.bus', //The naming is very flexible
               channels: ['redis-command'], //be sure if you defined same channels name as you defined below, you can bind multiple channels there, like send message to rabbitmq and redis at the same time 
            },
            {
               name: 'event.bus',
               channels: ['redis-event'],
            },
         ],
         channels: [
            new InMemoryChannelConfig({
               name: 'my-channel',
               middlewares: [],
               avoidErrorsForNotExistedHandlers: true,
            }),
            new RedisChannelConfig({
               name: 'redis-command',
               middlewares: [],
               avoidErrorsForNotExistedHandlers: false,
               queue: 'command-queue',
               connection: {
                  port: 6379,
                  host: '127.0.0.1',
               },
            }),
            new RedisChannelConfig({
               name: 'redis-event',
               middlewares: [],
               avoidErrorsForNotExistedHandlers: true,
               queue: 'event-queue',
               connection: {
                  port: 6379,
                  host: '127.0.0.1',
               },
            }),
         ],
         debug: true,
      }),
   ],
})
export class AppModule {
}

Key Features:

1. Multiple Message Buses:

   • Configure distinct buses for commands, and events:
     • command.bus (command processing).
     • event.bus (event processing).

2. In-Memory Channel:

   • Simple and lightweight channel suitable for non-persistent messaging or testing purposes.

3. Redis Channels:

   • Fully integrated Redis configuration using RedisChannelConfig.

4. Channel Details:

   • connection: Specifies the Redis server connection.
   • queue: Specify a Redis queue name to consume messages from.

5. Error Handling:

   • Use avoidErrorsForNotExistedHandlers in redis-event to gracefully handle missing handlers for event messages.

6. Debug Mode:

   • Enable debug: true to assist in monitoring and troubleshooting messages.

This configuration provides a solid foundation for integrating redis as part of your messaging system. It facilitates the decoupling of commands, events, and in-memory operations, ensuring reliable and scalable communication across distributed systems.

Configuration options

RedisChannel

RedisChannelConfig

| Property | Description | Default Value | |----------------------------------------|----------------------------------------------------------------------|-------------------| | name | Name of the Redis channel (e.g., 'redis-command'). | | | connection | Redis connection configuration (host, port, password, db). | | | queue | The Redis queue to consume messages from (e.g., 'my_app.command'). | | | enableConsumer | Enables or disables the consumer for this channel. | true | | avoidErrorsForNotExistedHandlers | Avoid errors if no handler is available for the message. | false | | keyPrefix | Optional prefix for keys stored in Redis. | |

Real world working example with RabbitMQ & Redis

https://github.com/nestjstools/messaging-rabbitmq-example

Keywords

nestjs messaging library, nestjs message bus, nestjs service bus, nestjs distributed systems, nestjs microservices messaging