unable to start a docker container running ember.js image, node_modules empty

I am trying to get ember.js to run in a docker container based on the image danlynn/ember-cli image

Tried different versions of Dockerfile and docker compose.yml, but I always end up with the docker-compose up command complaining of the following :

node_modules appears empty, you may need to run npm install

The image and container are created, but the container will not start.

I am new to the docker world, so any help would be greatly appreciated!

I am guessing I need to run npm install for the error to go away, but I added it to the Dockerfile so that It would run as the image is built, but that did not seem to help.

Here is my Dockerfile contents:

FROM danlynn/ember-cli
WORKDIR /code
COPY package.json /code
COPY bower.json /code
RUN ember init
RUN ember init --yarn
RUN bower --allow-root install
RUN npm install
COPY . /code
CMD ["ember", "serve"]

and the docker-compose.yml file:

version: "3"
services:
  ember_gui:
    build: .
    container_name: ember_dev
    volumes:
      - .:/code
    ports:
       - "4200:4200"
       - "7020:7020"
       - "5779:5779"

Finally, here is the package.json just in case

{
  "name": "EmberUI",
  "version": "0.0.1",
  "description": "Test app GUI",
  "main": "index.js",
  "author": "Testing",
  "license": "MIT",
  "dependencies": {
    "chai": "^4.1.2",
    "mocha": "^5.2.0"
  }
}