Docker-compose 将环境变量传递给 docker 容器并进入 npm 启动

Question

Having spent far too long on this, and read copious reference material on docker and many many stack overflow articles I have to admit defeat and ask the panel for help

What I want to achieve is to have my NODE_ENV defined somewhere outside of the docker files so it can be.gitignored.

So I want to be able to have a.env file in the same top level directory along with docker-compose.yml and Dockerfile that contains an entry for NODE_ENV.

Sounds pretty straight forward?

Firstly I had problems with the CMD statement in the dockerfile. Having researched it, I find that I need to do something like this

FROM node:latest

ENV NODE_ENV=development

WORKDIR /usr/src/app

COPY ./package*.json /usr/src/app/

RUN npm install

ADD . .

CMD ["sh", "-c", "npm run start:${NODE_ENV}"]

EXPOSE 3001

It works like a charm then I run it from the command line with

docker run -e "NODE_ENV=development".

However, bring docker-compose into the equation and it all goes wrong. And it doesn't give much in the way of errors either.

version: '3'
services:
  app:
    build: .
    environment: 
      - NODE_ENV=$NODE_ENV 
    ports:
      - '80:3001'
    links:
      - mongodb
  mongodb:
    image: mongo
    ports:
      - '27017:27017'

Now if I run this using docker-compose config I can see that the environment variable is being correctly set

services:
  app:
    build:
      context: /home/me/myproject
    environment:
      NODE_ENV: development
    links:
    - mongodb
    ports:
    - 80:3001/tcp
  mongodb:
    image: mongo
    ports:
    - 27017:27017/tcp
version: '3.0'

So my question is basically, can anyone spot what I am doing wrong? Or is this a bug in docker that I should report?

The only clues given from the logs is

app_1 exited with code 2

and in the container log

/bin/sh: 1: [: npm run ,: unexpected operator

Answer 1

I got it working by putting the environment variable line in the docker-compose in double quotes.

version: '3'
services:
  app:
    build: .
    environment: 
      - "NODE_ENV=$NODE_ENV" 
    ports:
      - '80:3001'
    links:
      - mongodb
  mongodb:
    image: mongo
    ports:
      - '27017:27017'