Redis

There is another way to work with Nest microservices. Instead of direct TCP communication, we could use amazing Redis feature - publish / subscribe.

还有另外一种与Nest 微服务的通信方式。我们可以使用强大的Redis功能publish / subscribe代替直接TCP通信。

Of course before you can use it, it is obligatory to install Redis.

当然，必须安装Redis之后才能使用。

创建微服务

To create Redis Microservice, you have to pass additional configuration in NestFactory.createMicroservice() method.

要创建Redis微服务就必须在NestFactory.createMicroservice()方法中传递其他配置。

const app = NestFactory.createMicroservice(
    MicroserviceModule, 
    { 
        transport: Transport.REDIS, 
        url: 'redis://localhost:6379' 
    }
);
app.listen(() => console.log('Microservice listen on port:', 5667 ));

And that's all. Now your microservice will subscribe to messages published via Redis. The rest works same - patterns, error handling, etc.

好了，现在你创建的微服务可以订阅通过Redis发布的消息了。其他的步骤与TCP相同--模式，异常处理等。

客户端

Now, let's see how to create client. Previously, your client instance configuration looks like that:

现在，让我们来创建客户端。在使用TCP时，你的客户端实例配置如下：

@Client({ transport: Transport.TCP, port: 5667 })
client: ClientProxy;

We want to use Redis instead of TCP, so we have to change those settings:

我们使用Redis代替TCP，所以我们应该更改这些设置：

@Client({ transport: Transport.REDIS, url: 'redis://localhost:6379' })
client: ClientProxy;

Easy, right? That's all. Other functionalities works same as in TCP communication.

是不是很简单？其他功能与TCP通信相同。