Merge pull request #59 from feliciagan/matching-mq

set up mq

Author: ruiqi7

backend/matching-service/.dockerignore

@@ -0,0 +1,5 @@
+coverage
+node_modules
+tests
+.env*
+*.md

backend/matching-service/.env.sample

@@ -2,3 +2,13 @@ NODE_ENV=development
 PORT=3002
 
 ORIGINS=http://localhost:5173,http://127.0.0.1:5173
+
+
+## FOR RABBITMQ, comment out the variables under whichever use case (1) or (2) that is not applicable
+# (1) RabbitMq for running matching service individually
+RABBITMQ_ADDR=amqp://localhost:5672  #comment out if use case is (2)
+
+# (2) RabbitMq for running matching service with other services using docker compose
+RABBITMQ_DEFAULT_USER=admin  #comment out if use case is (1)
+RABBITMQ_DEFAULT_PASS=password  #comment out if use case is (1)
+RABBITMQ_ADDR=amqp://admin:password@rabbitmq:5672  #comment out if use case is (1)

backend/matching-service/Dockerfile

@@ -0,0 +1,13 @@
+FROM node:20-alpine
+
+WORKDIR /matching-service
+
+COPY package*.json ./
+
+RUN npm ci
+
+COPY . .
+
+EXPOSE 3002
+
+CMD ["npm", "run", "dev"]

backend/matching-service/README.md

@@ -2,17 +2,24 @@
 
 ## Setting-up Matching Service
 
-1. In the `matching-service` directory, create a copy of the `.env.sample` file and name it `.env`.
+1. In the `matching-service` directory, create a copy of the `.env.sample` file and name it `.env`. If you are looking to run matching service with the other services using docker-compose, comment out the variable `RABBITMQ_ADDR` under use case (1) in the .env file. Otherwise, if you are looking to run matching service individually, comment out the variables `RABBITMQ_DEFAULT_USER`, `RABBITMQ_DEFAULT_PASS` and `RABBITMQ_ADDR` under use case (2) in the .env file.
 
-## Running Matching Service without Docker
+2. If you are running matching service together with other services using docker-compose, to set up credentials for RabbitMq, update the RabbitMq variables in the `.env` file. Update `RABBITMQ_DEFAULT_USER` and `RABBITMQ_DEFAULT_PASS` to what you want, then update `RABBITMQ_ADDR` to be `amqp://<RABBITMQ_DEFAULT_USER>:<RABBITMQ_DEFAULT_PASS>@rabbitmq:5672`.
+You can access RabbitMq management user interface locally with the username in `RABBITMQ_DEFAULT_USER` and password in `RABBITMQ_DEFAULT_PASS` at http://localhost:15672.
 
-1. Follow the instructions [here](https://nodejs.org/en/download/package-manager) to set up Node v20.
+3. If you are running matching service individually, you do not need to make any changes to `RABBITMQ_ADDR`. You can access RabbitMq management user interface locally with the username `guest` and password `guest` at http://localhost:15672.
 
-2. Open Command Line/Terminal and navigate into the `matching-service` directory.
+## Running Matching Service Individually with Docker
 
-3. Run the command: `npm install`. This will install all the necessary dependencies.
+1. Set up and run RabbitMq locally on your computer with the command `docker run -it --rm --name rabbitmq -p 5672:5672 -p 15672:15672 rabbitmq:4.0-management`.
 
-4. Run the command `npm start` to start the Matching Service in production mode, or use `npm run dev` for development mode, which includes features like automatic server restart when you make code changes.
+2. Follow the instructions [here](https://nodejs.org/en/download/package-manager) to set up Node v20.
+
+3. Open Command Line/Terminal and navigate into the `matching-service` directory.
+
+4. Run the command: `npm install`. This will install all the necessary dependencies.
+
+5. Run the command `npm start` to start the Matching Service in production mode, or use `npm run dev` for development mode, which includes features like automatic server restart when you make code changes.
 
 ## After running
 

backend/matching-service/config/rabbitmq.ts

@@ -0,0 +1,48 @@
+import amqplib, { Connection } from "amqplib";
+import dotenv from "dotenv";
+import { matchUsers } from "../utils/mq_utils";
+
+dotenv.config();
+
+let mrConnection: Connection;
+const queue = "match_requests";
+
+export const connectRabbitMq = async () => {
+  try {
+    mrConnection = await amqplib.connect(`${process.env.RABBITMQ_ADDR}`);
+    const consumerChannel = await mrConnection.createChannel();
+    await consumerChannel.assertQueue(queue);
+
+    consumerChannel.consume(queue, async (msg) => {
+      if (msg !== null) {
+        try {
+          await matchUsers(msg.content.toString());
+        } catch (error) {
+          console.error(error);
+        }
+        consumerChannel.ack(msg);
+      }
+    });
+  } catch (error) {
+    console.error(error);
+    process.exit(1);
+  }
+};
+
+type MatchRequestMessage = {
+  userId: string;
+  categories: string[] | string;
+  complexities: string[] | string;
+  sentTimestamp: number;
+  ttlInSecs: number;
+};
+
+export const sendRabbitMq = async (data: MatchRequestMessage) => {
+  try {
+    const senderChannel = await mrConnection.createChannel();
+    senderChannel.sendToQueue(queue, Buffer.from(JSON.stringify(data)));
+  } catch (error) {
+    console.log(error);
+    throw new Error("Failed to send match request");
+  }
+};

backend/matching-service/package-lock.json

@@ -13,6 +13,7 @@
   "author": "",
   "license": "ISC",
   "dependencies": {
+    "amqplib": "^0.10.4",
     "cors": "^2.8.5",
     "dotenv": "^16.4.5",
     "express": "^4.21.1",
@@ -21,6 +22,7 @@
   },
   "devDependencies": {
     "@eslint/js": "^9.12.0",
+    "@types/amqplib": "^0.10.5",
     "@types/cors": "^2.8.17",
     "@types/express": "^5.0.0",
     "@types/jest": "^29.5.13",

backend/matching-service/package.json

@@ -1,11 +1,39 @@
 import app from "./app.ts";
+import { connectRabbitMq } from "./config/rabbitmq.ts";
 
 const PORT = process.env.PORT || 3002;
 
 if (process.env.NODE_ENV !== "test") {
-  app.listen(PORT, () => {
-    console.log(
-      `Matching service server listening on http://localhost:${PORT}`
-    );
-  });
+  connectRabbitMq()
+    .then(() => {
+      console.log("RabbitMq connected!");
+
+      app.listen(PORT, () => {
+        console.log(
+          `Matching service server listening on http://localhost:${PORT}`
+        );
+      });
+
+      //can use this to test if rabbitmq works for you (import sendRabbitMq from rabbitmq.ts first)
+      /*const message1 = {
+        userId: "1",
+        categories: "Algorithms",
+        complexities: "Easy",
+        sentTimestamp: Date.now(),
+        ttlInSecs: 30,
+      };
+      sendRabbitMq(message1);
+      const message2 = {
+        userId: "2",
+        categories: "Algorithms",
+        complexities: "Medium",
+        sentTimestamp: Date.now(),
+        ttlInSecs: 30,
+      };
+      sendRabbitMq(message2);*/
+    })
+    .catch((err) => {
+      console.error("Failed to connect to RabbitMq");
+      console.error(err);
+    });
 }