sample: revert microservices sample local updates

sample/03-microservices/src/main.ts

@@ -1,6 +1,5 @@
 import { NestFactory } from '@nestjs/core';
-import { Transport } from '@nestjs/microservices';
-import { Kafka } from '@nestjs/microservices/external/kafka.interface';
+import { MicroserviceOptions, Transport } from '@nestjs/microservices';
 import { AppModule } from './app.module';
 
 async function bootstrap() {
@@ -16,65 +15,13 @@ async function bootstrap() {
    *
    */
   const app = await NestFactory.create(AppModule);
-  const msvc = app.connectMicroservice({
-    transport: Transport.KAFKA,
-    options: {
-      client: {
-        brokers: ['localhost:9092'],
-      },
-      consumer: {
-        groupId: 'my-kafka-consumer',
-      },
-    },
+  app.connectMicroservice<MicroserviceOptions>({
+    transport: Transport.TCP,
+    options: { retryAttempts: 5, retryDelay: 3000 },
   });
 
   await app.startAllMicroservices();
-  await app.listen(Math.floor(Math.random() * 1000) + 3000);
+  await app.listen(3001);
   console.log(`Application is running on: ${await app.getUrl()}`);
-
-  const kafka = msvc.unwrap<Kafka>();
-  const admin = kafka.admin();
-
-  const topicName = 'math';
-  try {
-    const topicExists = await admin.fetchTopicMetadata({
-      topics: [topicName],
-    });
-
-    console.log(
-      `Topic "${topicName}" already exists with ${topicExists.topics[0].partitions.length} partitions.`,
-    );
-
-    // Update "math.reply" topic to have 2 partitions if it has only 1 partition
-    const replyTopicName = 'math.reply';
-    const replyTopicExists = await admin.fetchTopicMetadata({
-      topics: [replyTopicName],
-    });
-    if (replyTopicExists.topics[0].partitions.length === 1) {
-      await admin.createPartitions({
-        topicPartitions: [
-          {
-            topic: replyTopicName,
-            count: 2,
-          },
-        ],
-      });
-      console.log(`Topic "${replyTopicName}" updated with 2 partitions.`);
-    }
-  } catch (error) {
-    if (error.message.includes('does not host this topic-partition')) {
-      await admin.createTopics({
-        topics: [
-          {
-            topic: topicName,
-            numPartitions: 2,
-          },
-        ],
-      });
-      console.log(`Topic "${topicName}" created with 2 partitions.`);
-    } else {
-      console.error('Error creating topic:', error.message);
-    }
-  }
 }
 bootstrap();

sample/03-microservices/src/math/math.controller.ts

@@ -1,27 +1,21 @@
 import { Controller, Get, Inject } from '@nestjs/common';
-import { ClientKafka, MessagePattern, Payload } from '@nestjs/microservices';
+import { ClientProxy, MessagePattern } from '@nestjs/microservices';
 import { Observable } from 'rxjs';
 import { MATH_SERVICE } from './math.constants';
 
 @Controller()
 export class MathController {
-  constructor(@Inject(MATH_SERVICE) private readonly client: ClientKafka) {}
-
-  async onModuleInit() {
-    this.client.subscribeToResponseOf('sum');
-    this.client.subscribeToResponseOf('math');
-    await this.client.connect();
-  }
+  constructor(@Inject(MATH_SERVICE) private readonly client: ClientProxy) {}
 
   @Get()
   execute(): Observable<number> {
-    const pattern = 'sum';
+    const pattern = { cmd: 'sum' };
     const data = [1, 2, 3, 4, 5];
     return this.client.send<number>(pattern, data);
   }
 
-  @MessagePattern('sum')
-  sum(@Payload() data: number[]): number {
+  @MessagePattern({ cmd: 'sum' })
+  sum(data: number[]): number {
     return (data || []).reduce((a, b) => a + b);
   }
 }

sample/03-microservices/src/math/math.module.ts

@@ -5,17 +5,7 @@ import { MathController } from './math.controller';
 
 @Module({
   imports: [
-    ClientsModule.register([
-      {
-        name: MATH_SERVICE,
-        transport: Transport.KAFKA,
-        options: {
-          client: {
-            brokers: ['localhost:9092'],
-          },
-        },
-      },
-    ]),
+    ClientsModule.register([{ name: MATH_SERVICE, transport: Transport.TCP }]),
   ],
   controllers: [MathController],
 })