environment variables in Expo when building with GitLab - react-native

Question

I'm trying to build a React Native APK with Expo (without ejecting). I can manage to locally get my environment variables from .env file when I do expo build:android in my local machine with all the project files.
When I do a push to my GitLab repository, I have this .gitlab-ci.yml file
---
image: node:alpine
cache:
key: ${CI_COMMIT_REF_SLUG}
paths:
- ~/.npm
- .jest
stages:
- test
- deploy
before_script:
- npm ci
jest-tests:
stage: test
script:
- npx jest --ci --passWithNoTests
expo-deployments:
stage: deploy
script:
- apk add --no-cache bash
- npx expo login -u $EXPO_USERNAME -p $EXPO_PASSWORD
- npx expo build:android --EXPO_ANDROID_GOOGLE_API_KEY $EXPO_ANDROID_GOOGLE_API_KEY --EXPO_IOS_GOOGLE_API_KEY $EXPO_IOS_GOOGLE_API_KEY --release-channel staging --non-interactive
- EXPO_ANDROID_GOOGLE_API_KEY=$EXPO_ANDROID_GOOGLE_API_KEY; EXPO_IOS_GOOGLE_API_KEY=$EXPO_IOS_GOOGLE_API_KEY; expo build:android --release-channel staging --non-interactive
I don't have in the repo the .env file, because of security.
Where all this variables are stored within each environment in GitLab:
(working perfectly)
EXPO_USERNAME = the username of my development account to access Expo.
EXPO_PASSWORD = the password of the account to access Expo.
(not working at all when trying to build)
EXPO_IOS_GOOGLE_API_KEY = "abcdefghijklmnopqrstuvwxyz"
EXPO_ANDROID_GOOGLE_API_KEY = "abcdefghijklmnopqrstuvwxz"
I wonder how could I set the Google Maps environment variables into the app when running the expo build:android command via GitLab CI pipeline:
- npx expo build:android

Answer 1

Finally I could manage to make this work the following way:
---
image: node:alpine
cache:
key: ${CI_COMMIT_REF_SLUG}
paths:
- ~/.npm
- .jest
stages:
- test
- deploy
before_script:
- npm ci
- ANDROID_GOOGLE_MAPS_API_KEY=${CI_COMMIT_BRANCH}_EXPO_ANDROID_GOOGLE_API_KEY
- IOS_GOOGLE_MAPS_API_KEY=${CI_COMMIT_BRANCH}_EXPO_IOS_GOOGLE_API_KEY
- export android=$( eval echo \$$ANDROID_GOOGLE_MAPS_API_KEY )
- export ios=$( eval echo \$$IOS_GOOGLE_MAPS_API_KEY )
jest-tests:
stage: test
script:
- npx jest --ci --passWithNoTests
expo-deployments:
stage: deploy
script:
- echo "EXPO_ANDROID_GOOGLE_API_KEY=$android" >> .env
- echo "EXPO_IOS_GOOGLE_API_KEY=$ios" >> .env
- apk add --no-cache bash
- npx expo login -u $EXPO_USERNAME -p $EXPO_PASSWORD
- npx expo build:android --release-channel staging --non-interactive
Where...
...CI_COMMIT_BRANCH is development|staging|production depending which branch in gitlab I am using.
...development_EXPO_ANDROID_GOOGLE_API_KEY | staging_EXPO_ANDROID_GOOGLE_API_KEY | production_EXPO_ANDROID_GOOGLE_API_KEY are variables that are stored at the Gitlab project.
... I am generating the .env file every time I run the script and saving there my variables with the respective value with: echo "EXPO_ANDROID_GOOGLE_API_KEY=$android" >> .env.
This way I don't need to push my .env file into Gitlab. I only need to define my variables in the settings of the project at Gitlab.
Hope this help to someone!