Env vars lost when building docker image from Gitlab CI

Question

I'm trying to build my React / NodeJS project using Docker and Gitlab CI.

When I build manually my images, I use.env file containing env vars, and everything is fine.

docker build --no-cache -f client/docker/local/Dockerfile . -t espace_client_client:local
docker build --no-cache -f server/docker/local/Dockerfile . -t espace_client_api:local

But when deploying with Gitlab, I can build successfully the image, but when I run it, env vars are empty in the client.

Here is my gitlab CI:

image: node:10.15
variables:
  REGISTRY_PACKAGE_CLIENT_NAME: registry.gitlab.com/company/espace_client/client
  REGISTRY_PACKAGE_API_NAME: registry.gitlab.com/company/espace_client/api
  REGISTRY_URL: https://registry.gitlab.com
  DOCKER_DRIVER: overlay
  # Client Side
  REACT_APP_API_URL: https://api.espace-client.company.fr
  REACT_APP_DB_NAME: company
  REACT_APP_INFLUX: https://influx-prod.company.fr
  REACT_APP_INFLUX_LOGIN: admin
  REACT_APP_HOUR_GMT: 2


stages:
  - publish

docker-push-client:
  stage: publish
  before_script:
    - docker login -u gitlab-ci-token -p $CI_BUILD_TOKEN $REGISTRY_URL
  image: docker:stable
  services:
    - docker:dind
  script:
    - docker build --no-cache -f client/docker/prod/Dockerfile . -t $REGISTRY_PACKAGE_CLIENT_NAME:latest
    - docker push $REGISTRY_PACKAGE_CLIENT_NAME:latest

Here is the Dockerfile for the client

FROM node:10.15-alpine
WORKDIR /app
COPY package*.json ./
ENV NODE_ENV production

RUN npm -g install serve && npm install
COPY . .
RUN npm run build
EXPOSE 3000
CMD [ "serve", "build", "-l", "3000" ]

Why is there such a difference between the 2 process?

Answer 1

According to your answer in comments, GitLab CI/CD environment variables doesn't solve your issue. Gitlab CI environment is actual only in context of GitLab Runner that builds and|or deploys your app.

So, if you are going to propagate Env vars to the app, there are several ways to deliver variables from .gitlab-cy.yml to your app:

ENV instruction Dockerfile

Eg

FROM node:10.15-alpine
WORKDIR /app
COPY package*.json ./
ENV   NODE_ENV production
ENV   REACT_APP_API_URL: https://api.espace-client.company.fr
ENV   REACT_APP_DB_NAME: company
ENV   REACT_APP_INFLUX: https://influx-prod.company.fr
ENV   REACT_APP_INFLUX_LOGIN: admin
ENV   REACT_APP_HOUR_GMT: 2

RUN npm -g install serve && npm install
COPY . .
RUN npm run build
EXPOSE 3000
CMD [ "serve", "build", "-l", "3000" ]

docker-compose environment directive

web:
  environment:
    - NODE_ENV=production
    - REACT_APP_API_URL=https://api.espace-client.company.fr
    - REACT_APP_DB_NAME=company
    - REACT_APP_INFLUX=https://influx-prod.company.fr
    - REACT_APP_INFLUX_LOGIN=admin
    - REACT_APP_HOUR_GMT=2

Docker run -e

(Not your case, just for information)

docker -e REACT_APP_DB_NAME="company"

PS Try Gitlab CI variables

There is convenient way to store variables outside of your code: Custom environment variables

You can set them up easily from the UI . That can be very powerful as it can be used for scripting without the need to specify the value itself.

_{(source: gitlab.com )}