feat: Node.js consumer amqplib

package.json

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+{
+  "name": "iot-consumer",
+  "version": "1.0.0",
+  "main": "server.js",
+  "scripts": { "start": "node server.js" },
+  "dependencies": { "amqplib": "^0.10.0", "express": "^4.21.0", "redis": "^4.7.0", "mongodb": "^6.0.0" }
+}

requirements.txt

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+Flask>=3.0
+gunicorn>=21.2
+redis>=5.0
+pymongo>=4.0

server.js

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+const amqp = require("amqplib");
+const express = require("express");
+const { createClient } = require("redis");
+const { MongoClient } = require("mongodb");
+
+const RMQ_HOST = process.env.RMQ_HOST || "localhost";
+const RMQ_PORT = parseInt(process.env.RMQ_PORT || "5672");
+const RMQ_USER = process.env.RMQ_USER || "guest";
+const RMQ_PASS = process.env.RMQ_PASS || "guest";
+const RMQ_QUEUE = process.env.RMQ_QUEUE || "iot-events";
+
+const REDIS_HOST = process.env.REDIS_HOST || "localhost";
+const REDIS_PORT = parseInt(process.env.REDIS_PORT || "6379");
+const REDIS_PASS = process.env.REDIS_PASS || undefined;
+
+const MONGO_URI = process.env.MONGO_URI || "mongodb://localhost:27017/iot";
+const MONGO_DB = process.env.MONGO_DB || "iot";
+
+let consumed = 0, errors = 0;
+let redis, mongo, mongoColl;
+
+async function getRedis() {
+  if (!redis) {
+    redis = createClient({ socket: { host: REDIS_HOST, port: REDIS_PORT }, password: REDIS_PASS });
+    redis.on("error", () => {});
+    await redis.connect();
+    console.log("Redis connected");
+  }
+  return redis;
+}
+
+async function getMongo() {
+  if (!mongo) {
+    mongo = new MongoClient(MONGO_URI);
+    await mongo.connect();
+    mongoColl = mongo.db(MONGO_DB).collection("iot_events");
+    await mongoColl.createIndex({ timestamp: 1 }, { expireAfterSeconds: 604800 });
+    console.log("MongoDB connected");
+  }
+  return mongoColl;
+}
+
+async function store(event) {
+  const r = await getRedis();
+  await r.hSet("iot:latest", event.sensor_id, JSON.stringify({
+    value: event.value, unit: event.unit, location: event.location, timestamp: event.timestamp,
+  }));
+  await r.hIncrBy("iot:counters", event.device_type, 1);
+  await r.zAdd("iot:recent", [{ score: 0, value: JSON.stringify(event) }]);
+  await r.zRemRangeByRank("iot:recent", 0, -1001);
+  const coll = await getMongo();
+  await coll.insertOne({
+    event_id: event.event_id, sensor_id: event.sensor_id,
+    device_type: event.device_type, location: event.location,
+    value: event.value, unit: event.unit, timestamp: new Date(event.timestamp),
+  });
+}
+
+async function start() {
+  const conn = await amqp.connect(`amqp://${RMQ_USER}:${RMQ_PASS}@${RMQ_HOST}:${RMQ_PORT}`);
+  const ch = await conn.createChannel();
+  await ch.assertQueue(RMQ_QUEUE, { durable: true });
+  ch.prefetch(10);
+  await ch.consume(RMQ_QUEUE, async (msg) => {
+    try {
+      if (msg) {
+        const event = JSON.parse(msg.content.toString());
+        await store(event);
+        consumed++;
+        ch.ack(msg);
+        if (consumed % 10 === 0) console.log(`Consumed ${consumed} events`);
+      }
+    } catch (e) {
+      errors++;
+      console.error("Error:", e.message);
+    }
+  });
+  console.log(`Consumer listening on queue: ${RMQ_QUEUE}`);
+}
+
+const app = express();
+app.get("/", (req, res) => res.json({ service: "iot-consumer", status: "running", queue: RMQ_QUEUE, consumed, errors }));
+app.get("/health", (req, res) => res.json({ status: "ok" }));
+app.listen(process.env.PORT || 3000, () => { console.log("Consumer started"); start(); });