PORT environment variable changed to accept multiple different ports (defaults...

PORT environment variable changed to accept multiple different ports (defaults to 3000). Docker compose file edited to have two backends using the same Docker Image and using the same Mongo DB database.

backend/server.js

@@ -10,7 +10,7 @@ const cors = require('cors');
 app.use(cors());
 
 // Start the server
-const PORT = 3000;
+const PORT = process.env.PORT || 3000; // <--- Dynamic port
 
 // Middleware to parse JSON
 app.use(express.json());

docker-compose.yml

-version: '3.9'
+version: '3.8'
 
 services:
-  mongo:
+  mongo-dev:
     image: mongo
-    container_name: mongo
+    container_name: mongo-dev
     ports:
       - "27017:27017"
-    environment:
-      MONGO_INITDB_ROOT_USERNAME: admin
-      MONGO_INITDB_ROOT_PASSWORD: secret
+    volumes:
+      - mongo-data:/data/db
 
-  app:
+  backend1:
     build: .
-    container_name: bookapp
+    container_name: backend1
     ports:
-      - "3000:3000"
+      - "3001:3000"
+    environment:
+      - PORT=3000
+      - MONGO_URL=mongodb://mongo-dev:27017/BookDatabase
     depends_on:
-      - mongo
+      - mongo-dev
+
+  backend2:
+    build: .
+    container_name: backend2
+    ports:
+      - "3002:3000"
     environment:
-      - MONGO_URI=mongodb://admin:secret@mongo:27017/BookDatabase?authSource=admin
+      - PORT=3000
+      - MONGO_URL=mongodb://mongo-dev:27017/BookDatabase
+    depends_on:
+      - mongo-dev
+
+volumes:
+  mongo-data: