Why are environment variables not being recognized during a React Native Android build, even though I set them using GitHub Actions?

I'm trying to set up environment variables in a GitHub Actions workflow for my React Native Android build (./gradlew bundleRelease). Despite setting the environment variables either through the env section or using export commands, the build is not recognizing some of the variables. Specifically, I keep getting errors stating that certain environment variables are missing during the build process.

Here are the methods I've tried:

1. Setting the environment variables directly using GitHub Actions' env syntax:

   - name: Set environment variables
     env:
       MAIN_URL: ${{ vars.MAIN_URL }}
       ORIGIN: ${{ vars.ORIGIN }}
       ENV: ${{ vars.ENV }}
       AWS_REGION: ${{ secrets.AWS_REGION }}
       AWS_USER_POOL_ID: ${{ secrets.AWS_USER_POOL_ID }}
       AWS_APP_CLIENT_WEB_ID: ${{ secrets.AWS_APP_CLIENT_WEB_ID }}
       AWS_IDENTITY_POOL_ID: ${{ secrets.AWS_IDENTITY_POOL_ID }}
       AWS_EXTERNAL_USER_POOLS_ID: ${{ secrets.AWS_EXTERNAL_USER_POOLS_ID }}
       AWS_EXTERNAL_USER_POOLS_WEB_CLIENT_ID: ${{ secrets.AWS_EXTERNAL_USER_POOLS_WEB_CLIENT_ID }}
       ENABLE_SENTRY: ${{ secrets.ENABLE_SENTRY }}
   

2. Exporting the environment variables using export:

   - name: Export environment variables
     run: |
       export MAIN_URL=$MAIN_URL
       export ORIGIN=$ORIGIN
       export ENV=$ENV
       export AWS_REGION=$AWS_REGION
       export AWS_USER_POOL_ID=$AWS_USER_POOL_ID
       export AWS_APP_CLIENT_WEB_ID=$AWS_APP_CLIENT_WEB_ID
       export AWS_IDENTITY_POOL_ID=$AWS_IDENTITY_POOL_ID
       export AWS_EXTERNAL_USER_POOLS_ID=$AWS_EXTERNAL_USER_POOLS_ID
       export AWS_EXTERNAL_USER_POOLS_WEB_CLIENT_ID=$AWS_EXTERNAL_USER_POOLS_WEB_CLIENT_ID
       export ENABLE_SENTRY=$ENABLE_SENTRY
   

Configure project :app Reading env from: .env

*** Missing .env file ****

However, the build command (./gradlew bundleRelease) does not seem to recognize the variables and throws errors about missing values. What am I doing wrong?

Answer:

Fortunately, I was able to resolve it! Here's what worked for me, though I want to emphasize that this isn’t the only solution—feel free to share any other suggestions you might have!

This issue is common in React Native Android builds, particularly when you're trying to pass environment variables to Gradle during the build process. The solution lies in ensuring that Gradle can access these environment variables. Even though you've set the environment variables using env or export, Gradle might not be picking them up properly, especially in CI/CD environments.

Solution:

You can dynamically create a .env file with all the environment variables before starting the build process. This method works because React Native uses the .env file to configure the environment variables at runtime, and Gradle can read from this file.

Here’s how you can fix it:

1. Dynamically create a .env file with the required environment variables:

# Create .env file dynamically with environment variables
- name: Create .env file
  run: |
    echo "MAIN_URL=${{ vars.MAIN_URL }}" > .env
    echo "ORIGIN=${{ vars.ORIGIN }}" >> .env
    echo "ENV=${{ vars.ENV }}" >> .env
    echo "AWS_REGION=${{ secrets.AWS_REGION }}" >> .env
    echo "AWS_USER_POOL_ID=${{ secrets.AWS_USER_POOL_ID }}" >> .env
    echo "AWS_APP_CLIENT_WEB_ID=${{ secrets.AWS_APP_CLIENT_WEB_ID }}" >> .env
    echo "AWS_IDENTITY_POOL_ID=${{ secrets.AWS_IDENTITY_POOL_ID }}" >> .env
    echo "AWS_EXTERNAL_USER_POOLS_ID=${{ secrets.AWS_EXTERNAL_USER_POOLS_ID }}" >> .env
    echo "AWS_EXTERNAL_USER_POOLS_WEB_CLIENT_ID=${{ secrets.AWS_EXTERNAL_USER_POOLS_WEB_CLIENT_ID }}" >> .env
    echo "ENABLE_SENTRY=${{ secrets.ENABLE_SENTRY }}" >> .env
    cat .env # Optional: to verify the file's contents

2. Ensure that Gradle can access the .env file:

Make sure your React Native project is configured to use the .env file during the build process. Typically, you'll need a package like react-native-dotenv to make sure the .env variables are properly loaded during the build.

Why ThiI/s Works:

• Gradle and React Native do not always automatically recognize environment variables passed through the standard CCD setup, especially when they're not explicitly passed as Gradle properties.
• By creating a .env file at runtime and ensuring it's available to React Native, you're giving the build process a structured way to access these variables.
• This method eliminates issues related to missing environment variables during the build process and ensures that Gradle can access them as expected.

Additional Tips:

• Debugging: You can add a cat .env command in your workflow to verify the environment variables have been correctly set.
• Gradle configuration: If needed, you can also pass the environment variables directly to Gradle using the -P option (e.g., -PMAIN_URL=$MAIN_URL), but this method with the .env file is typically more reliable.

By following this approach, you should be able to resolve the issue with missing environment variables in your React Native Android build process.