Running Nodemon in Docker Container

Question

I'm trying to run Nodemon package in a Docker Network with two services, NodeJs and MongoDB.

When I run the app with npm start, nodemon works: I can connect to localhost:3000 and I have the changes in real time. But as soon as I run npm run docker (docker-compose up --build), I can connect to localhost:3000 but I'm not able to see real-time changes on my application nor console.

docker-compose.yml

    version: '3.7'
services:
  app:
    container_name: NodeJs
    build: .
    volumes:
      - "./app:/usr/src/app/app"
    ports:
      - 3000:3000
  mongo_db:
    container_name: MongoDB
    image: mongo
    volumes:
      - mongo_db:/data/db
    ports:
      - 27017:27017
volumes:
  mongo_db:

dockerfile

FROM node:alpine
WORKDIR /app
COPY package.json /.
RUN npm install
COPY . /app
CMD ["npm", "run", "dev"]

package.json

{
  "name": "projectvintedapi",
  "version": "0.0.0",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "node index.js",
    "dev": "nodemon index.js",
    "docker": "docker-compose up --build"
  },
  "license": "ISC",
  "dependencies": {
    "dotenv": "^16.0.0",
    "express": "^4.17.3",
    "mongodb": "^4.5.0",
    "nodemon": "^2.0.15"
  }
}

Answer 1

Fixed it: it was for bind mount

dockerfile

FROM node:16.13.2
WORKDIR /app
COPY package.json package-lock.json ./
RUN npm ci
COPY . ./
CMD ["npm", "run", "start"]

docker-compose.yml

   version: '3.7'
    services:
      app:
        container_name: NodeJs
        build: .
        command: npm run dev
        volumes:
          - .:/app
        ports:
          - 3000:3000
      mongo_db:
        container_name: MongoDB
        image: mongo
        volumes:
          - mongo_db:/data/db
        ports:
          - 27017:27017
    volumes:
      mongo_db: