Install node_modules inside Docker container and synchronize them with host

Question

I have the problem with installing node_modules inside the Docker container and synchronize them with the host. My Docker\'s version is 18.03.1-ce, build

Answer 1

I'm not sure to understand why you want your source code to live inside the container and host and bind mount each others during development. Usually, you want your source code to live inside the container for deployments, not development since the code is available on your host and bind mounted.

Your docker-compose.yml

frontend:
  volumes:
    - ./app/frontend:/usr/src/app

Your Dockerfile

FROM node:10

RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app

Of course you must run npm install first time and everytime package.json changes, but you run it inside the container so there is no cross-platform issue: docker-compose exec frontend npm install

Finally start your server docker-compose exec frontend npm start

And then later, usually in a CI pipeline targetting a deployment, you build your final image with the whole source code copied and node_modules reinstalled, but of course at this point you don't need anymore the bind mount and "synchronization", so your setup could look like :

docker-compose.yml

frontend:
  build:
    context: ./app/frontend
    target: dev
  volumes:
    - ./app/frontend:/usr/src/app

Dockerfile

FROM node:10 as dev

RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app

FROM dev as build

COPY package.json package-lock.json ./
RUN npm install

COPY . ./

CMD ["npm", "start"]

And you target the build stage of your Dockerfile later, either manually or during a pipeline, to build your deployment-ready image.

I know it's not the exact answer to your questions since you have to run npm install and nothing lives inside the container during development, but it solves your node_modules issue, and I feel like your questions are mixing development and deployment considerations, so maybe you thought about this problem in the wrong way.