docker-compose build environment variable

There’s a note in the docs:

Note: If your service specifies a build option, variables defined in environment are not automatically visible during the build. Use the args sub-option of build to define build-time environment variables.

It’s also described in here. First (as mentioned above), you need to specify ARG in Dockerfile:

FROM mhart/alpine-node:10
ARG NODE_ENV
ENV NODE_ENV $NODE_ENV
ADD . /app
WORKDIR /app
RUN apk --no-cache add --virtual builds-deps build-base python &&\
    yarn global add nodemon &&\
    yarn &&\
    apk del builds-deps build-base python

And then edit your docker-compose file to include the argument during build, like so:

build:
  context: .
  dockerfile: Dockerfile-preprod
  args:
    - NODE_ENV=development

Or even

build:
  context: .
  dockerfile: Dockerfile-preprod
  args:
    - NODE_ENV=${NODE_ENV}