How to mqtt publish on NestJS? - mqtt

Question

I am making mqtt client using NestJS
I used #MessagePattern to confirm the subscription. (#Ctx, #Payload information is also checked normally.)
By the way, mqtt client information is created in app.module
I tried to use MqttClient using #Inject in Controller
The following error occurs in client.push.
Help me
(The controller's client.publish does not work.)
[main.ts]
async function bootstrap() {
/*const app = await NestFactory.create(AppModule);
await app.listen(3000);*/
const app = await NestFactory.createMicroservice<MicroserviceOptions>(
AppModule,{
transport:Transport.MQTT,
options:{
url : 'serverIp',
username : 'name',
password : 'pwd',
port : 1883,
protocol : 'mqtt'
}
},
);
app.listen(() =>{
console.log('[Agent Server is Listening...]');
})
}
bootstrap();
[app.module.ts]
#Module({
imports: [
ClientsModule.register([
{
name: 'MQ_CLIENT',
transport: Transport.MQTT,
options: {
host:'serverIp',
port:1883,
//protocol:'mqtt',
username:'name',
password:'pwd'
}
},
]),
ConfigModule
],
controllers: [AppController, VcController],
providers: [AppService, VcService],
})
export class AppModule {}
[Controller]
#Controller('vc')
export class VcController {
constructor(
#Inject(WINSTON_MODULE_NEST_PROVIDER) private readonly logger : LoggerService,
#Inject('MQ_CLIENT') private client : MqttClient
) {}
#MessagePattern('SomeTopic)
private tempFunction(#Ctx() context: MqttContext, #Payload() data){
this.client.publish('Publish TopicId', 'tttaaaaaa'); //The problem arises here
}
}
[Error Messgae]
TypeError: callback is not a function
at ClientMqtt.publish (C:\Wrok_Git\Demo\20201013_nestjsMqtt\mqtt-agent-02\node_modules\#nestjs\microservices\client\client-mqtt.js:104:13)
at VcController.vcTest (C:\Wrok_Git\Demo\20201013_nestjsMqtt\mqtt-agent-02\dist\controller\vc\vc.controller.js:40:21)
at C:\Wrok_Git\Demo\20201013_nestjsMqtt\mqtt-agent-02\node_modules\#nestjs\microservices\context\rpc-context-creator.js:44:33
at processTicksAndRejections (internal/process/task_queues.js:97:5)
at async C:\Wrok_Git\Demo\20201013_nestjsMqtt\mqtt-agent-02\node_modules\#nestjs\microservices\context\rpc-proxy.js:11:32
at async ServerMqtt.handleEvent (C:\Wrok_Git\Demo\20201013_nestjsMqtt\mqtt-agent-02\node_modules\#nestjs\microservices\server\server.js:61:32)

Answer 1

I did a little digging and came up with the following:
https://github.com/nestjs/nest/issues/6403
The gist of it, you need to call mqttClient.connect() beforehand, but you will not find that function in the interface for it.

Answer 2

This works for me -
constructor(#Inject('MQ_CLIENT') private client: ClientProxy) {
client.connect();
}
#MessagePattern('SomeTopic')
private tempFunction(#Ctx() context: MqttContext, #Payload() data) {
this.client.emit('help', 'data');
}

Answer 3

The code of question is all OK.
Only replace the line
this.client.publish('Publish TopicId', 'tttaaaaaa');
with
this.client.emit('Publish TopicId', 'tttaaaaaa')