为什么node_modules在构建后仍会从Docker中消失？

Question

I'm mimicking the setup found here https://github.com/mjhea0/node-docker-workflow . Using docker-compose to link 2 docker containers (node, redis).

Here's the circle ci file:

machine:
  services:
    - docker

dependencies:
  override:
    - sudo pip install -U docker-compose

test:
  override:
    - docker-compose run -d --no-deps node
    - cd node; npm test

And here is my node Dockerfile:

FROM dockerfile/nodejs

RUN mkdir /src

RUN npm install nodemon -g

WORKDIR /src
ADD . /src
RUN npm install

EXPOSE 3000

CMD npm start

The tests are constantly failing because chai can't be found. This is due to node_modules disappearing once the build is complete.

Literally between these 2 steps in the circle.yml file node_modules are installed by npm install, and then they're gone by the time the npm test command is run.

test:
  override:
    - docker-compose run -d --no-deps node
    - cd node; npm test

I can't figure out why this is happening. As i'm just starting out with Docker, can someone please (in laymens terms) explain fairly thoroughly what is wrong with the repo i'm using above, and how to solve it.

Thanks!

Answer 1

Well, it turns out it was something very, very simple, and probably rather silly/obvious.

The tests aren't being run inside the container.

docker-compose run -d --no-deps node

This line runs the container in detached mode. Which means when the next command runs, it's running outside the container.

To solve this, simply remove the -d , so the next command runs inside the container.

docker-compose run --no-deps node

Simple.