英文:
MQTT + NestJS TypeError when running with NodeJS directly
问题
以下是您要翻译的内容：
# NestJs + MQTT error when trying to host with PM2/NodeJS我正在尝试使用NestJs中的Controller和MessagePatterns来处理一些MQTT主题上的消息。我还在使用一个NX monorepo。当我运行以下命令时，一切都正常运行：
yarn nx serve api
我正在制定部署策略，当我使用以下命令编译我的项目时，一切都正常：
yarn nx run-many --t=build --configuration=production
问题出现在当我尝试运行编译后的项目时：
node ./dist/apps/api/main.js
这会导致以下错误消息：
/home/user/Desktop/project/node_modules/mqtt/lib/client.js:701
const resubscribe = obj.resubscribe
^
TypeError: Cannot read properties of undefined (reading 'resubscribe')
at MqttClient.subscribe (/home/user/Desktop/project/node_modules/mqtt/lib/client.js:701:27)
at /home/user/Desktop/project/node_modules/@nestjs/microservices/server/server-mqtt.js:40:24
at Array.forEach (<anonymous>)
at ServerMqtt.bindEvents (/home/user/Desktop/project/node_modules/@nestjs/microservices/server/server-mqtt.js:38:28)
at ServerMqtt.start (/home/user/Desktop/project/node_modules/@nestjs/microservices/server/server-mqtt.js:32:14)
at ServerMqtt.listen (/home/user/Desktop/project/node_modules/@nestjs/microservices/server/server-mqtt.js:24:18)
at /home/user/Desktop/project/node_modules/@nestjs/microservices/nest-microservice.js:107:25
at new Promise (<anonymous>)
at NestMicroservice.listen (/home/user/Desktop/project/node_modules/@nestjs/microservices/nest-microservice.js:106:16)
# 我已尝试了以下方法（但没有成功）- 不同版本的NodeJS（目前是v18.16.0）- 不同版本的MQTT库- 注释掉代码的某些部分：以下是我main.ts文件的代码片段：
const mqtt_app = await NestFactory.createMicroservice(AppModule, {
transport: Transport.MQTT,
options: {
url: process.env.MQTT_URL,
username: process.env.MQTT_USERNAME,
password: process.env.MQTT_PASSWORD,
},
});
mqtt_app.listen();
如果我不调用```mqtt_app.listen();```，那就没有问题，但这也意味着与MQTT相关的任何内容都不起作用。我的mqtt.controller文件：
import { Controller } from '@nestjs/common';
import { MessagePattern, Payload } from '@nestjs
英文:
NestJs + MQTT error when trying to host with PM2/NodeJS
I am trying to use a Controller with MessagePatterns in NestJs to handle messages on some MQTT topics. I am also using an NX monorepo. Everything works fine when I run:
yarn nx serve api
I am working on a deployment strategy, and when I compile my project using:
yarn nx run-many --t=build --configuration=production
Everything is compiling fine.
The issue comes in when I try to run the compiled project using
node ./dist/apps/api/main.js
This causes the following error-message
/home/user/Desktop/project/node_modules/mqtt/lib/client.js:701const resubscribe = obj.resubscribe^TypeError: Cannot read properties of undefined (reading 'resubscribe')at MqttClient.subscribe (/home/user/Desktop/project/node_modules/mqtt/lib/client.js:701:27)at /home/user/Desktop/project/node_modules/@nestjs/microservices/server/server-mqtt.js:40:24at Array.forEach (<anonymous>)at ServerMqtt.bindEvents (/home/user/Desktop/project/node_modules/@nestjs/microservices/server/server-mqtt.js:38:28)at ServerMqtt.start (/home/user/Desktop/project/node_modules/@nestjs/microservices/server/server-mqtt.js:32:14)at ServerMqtt.listen (/home/user/Desktop/project/node_modules/@nestjs/microservices/server/server-mqtt.js:24:18)at /home/user/Desktop/project/node_modules/@nestjs/microservices/nest-microservice.js:107:25at new Promise (<anonymous>)at NestMicroservice.listen (/home/user/Desktop/project/node_modules/@nestjs/microservices/nest-microservice.js:106:16)
I have tried the following (with no success)
- Different NodeJS versions (Currently on v18.16.0)
- Different versions of the MQTT library
- Commenting out certain parts of code:
Here is a snippet from my main.ts file:
const mqtt_app = await NestFactory.createMicroservice(AppModule, {transport: Transport.MQTT,options: {url: process.env.MQTT_URL,username: process.env.MQTT_USERNAME,password: process.env.MQTT_PASSWORD,},});mqtt_app.listen();
If I don't call mqtt_app.listen();, I don't have an issue, but that also means that nothing related to MQTT will work.
My mqtt.controller file:
import { Controller } from '@nestjs/common';import { MessagePattern, Payload } from '@nestjs/microservices';@Controller()export class MqttController {@MessagePattern(process.env.MQTT_TOPIC_1)async mqtt_a(@Payload() data) {console.log(`Received ${data} on ${process.env.MQTT_TOPIC_1}`);return `Received ${data} on ${process.env.MQTT_TOPIC_1}}`};@MessagePattern(process.env.MQTT_TOPIC_2)async mqtt_b(@Payload() data) {console.log(`Received ${data} on ${process.env.MQTT_TOPIC_2}`);return `Received ${data} on ${process.env.MQTT_TOPIC_2}}`}}
If I comment out the two @MmessagePattern()'s and functions mqtt_a and mqtt_b, everything seems to work fine.
I suspect that when I run this using NodeJS directly, it tries to 'subscribe' to a topic before the microservice is running, or something simillar?
Maybe I am missing something very obvious, but I am out of ideas and any help regarding this will be greatly appreciated!
答案1
得分: 0
问题已解决！
问题出在使用 .env 来定义消息模式
@MessagePattern(process.env.MQTT_TOPIC_2)
已修复，改为使用
@MessagePattern('topic')
不过，这似乎只在使用 NodeJS 运行编译后的代码时存在问题，而在直接使用 NX / NestJS 运行项目时，使用 process.env.* 却可以正常工作。
英文:
Problem solved!
The issue was using .env for the messagepatterns
@MessagePattern(process.env.MQTT_TOPIC_2)
Fixed by rather doing
@MessagePattern('topic')
This only seems to be an issue when running the compiled code using NodeJS though, and for some reason using process.env.* works fine when running the project using NX / NestJS directly.
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论