如果本地计算机上未安装 node_modules，则 Docker 组合不起作用

Question

My goal is to create docker dev environment for a full-stack app: React, NodeJS and MongoDb (with hot reloading). My current dev environment works, but I noticed that "docker compose up" will only work, if the node_modules are installed on my local machine - it otherwise returns an error that nodemon is not installed, or react-scripts not found. It seems like docker is looking for the node files in my local machine, but it should be installing them in the container during the compose, right?

docker-compose.yml

version: '3.8'
services:
  server:
    build: ./server
    container_name: server_backend
    ports:
      - '7000:7000'
    volumes:
      - ./server:/app
  client:
    build: ./client
    container_name: client_frontend
    ports:
      - '3000:3000'
    volumes:
      - ./client:/app
    stdin_open: true
    tty: true

Dockerfile (backend server)

FROM node:16-bullseye-slim
WORKDIR /app
COPY package.json .
COPY package-lock.json .
RUN npm install
COPY . .
EXPOSE 7000
CMD ["node", "index.js"]

Dockerfile (frontend)

FROM node:16-bullseye-slim
WORKDIR /app
COPY package.json .
RUN npm install
COPY . .
EXPOSE 3000
CMD ["npm", "start"]

app architecture

- MyApp
-- client
-- server

Answer 1

Can it be that you are copying the whole directory with the node_modules when you execute the COPY. . COPY. . command, try and either specifiy the directory to copy or add a .dockerignore .

Found this in the documentation, https://docs.docker.com/language/nodejs/build-images/#create-a-dockerignore-file