Automating Flutter App Builds with GitHub Actions: Firebase App Distribution and GitHub Releases

Introduction

This documentation provides a step-by-step guide on setting up GitHub Actions for your Flutter project to automate the process of building and uploading releases to both Firebase App Distribution and GitHub Releases. It covers generating necessary tokens, configuring secrets, and creating a workflow for continuous integration and deployment.

1. Generate a Personal Access Token on GitHub

A personal access token on GitHub functions like an OAuth access token and authenticates access to the GitHub API.

Navigate to your Git account settings, then Developer Settings. Click the Personal access tokens menu, then click Generate new token.
Select repo as the scope. The token will be applicable for all the specified actions in your repositories.
Click Generate Token. GitHub will display the personal access token only once. Ensure that you copy the token and store it in a safe space.

This token will be used in the Integration function's code, enabling access to necessary repository information.

2. Create a New Secret on GitHub

To securely store sensitive information like tokens, create a new secret in your GitHub repository:

Navigate to your repository on GitHub.
Go to Settings > Secrets & Variables and click Actions.
Click on New repository secret.
Enter a Name for your Secret (e.g., FIREBASE_APP_ID) and paste the value of the token you generated earlier.
Click Add secret to save.

3. Generate a Firebase CLI Authentication Token

If your project uses Firebase, you'll need to generate a Firebase CLI authentication token:

Install Firebase CLI: Run the following command:
```
npm install -g firebase-tools
```
Login to Firebase: Use the command:
```
firebase login
```
This will open a browser window for login.
Generate a Token: After logging in, generate a token with:
```
firebase login:ci
```

Copy and securely store the generated token in GitHub actions secrets

4. Set Up GitHub Actions Workflow

Create a new file in your repository at .github/workflows/main.yml with the following content:

name: Deploy Build and Release apk

on:
  pull_request:
    branches:
      - main

  push:
    branches:
      - main

jobs:
  build:
    name: Deploy Build APK
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - uses: actions/setup-java@v3
        with:
          distribution: "zulu"
          java-version: "17"

      - run: git config --global --add safe.directory /github/workspace

      - name: Set up Node.js
        uses: actions/setup-node@v4.0.4
        with:
          node-version: "18" # Specify your Node.js version

      - name: Get Flutter Version
        id: flutter_version
        uses: bungabear/flutter_version_read@main
        with:
          file: ./pubspec.yaml

      - name: Flutter App Version Number
        run: echo 'version_number:' ${{ steps.flutter_version.outputs.version_number }}

      - name: Flutter App Build Number
        run: echo 'build_number:' ${{ steps.flutter_version.outputs.build_number }}

      - uses: subosito/flutter-action@v2
        with:
          flutter-version: 3.24.3

      - run: flutter pub get
      - run: flutter build apk

      - name: Rename APK
        run: |
          VERSION_NUMBER=${{ steps.flutter_version.outputs.version_number }}
          BUILD_NUMBER=${{ steps.flutter_version.outputs.build_number }}
          mv build/app/outputs/flutter-apk/app-release.apk build/app/outputs/flutter-apk/app_name-${VERSION_NUMBER}-${BUILD_NUMBER}.apk

      - name: Upload the APK onto Github
        uses: ncipollo/release-action@v1
        with:
          artifacts: "build/app/outputs/flutter-apk/*.apk"
          token: ${{ secrets.GH_TOKEN }}
          tag: ${{ steps.flutter_version.outputs.version_number }}+${{ steps.flutter_version.outputs.build_number }}

      - name: Upload to Firebase App Distribution
        env:
          FIREBASE_TOKEN: ${{ secrets.FIREBASE_TOKEN }}
        run: |
          curl -sL https://firebase.tools | bash  # Install Firebase CLI
          firebase appdistribution:distribute build/app/outputs/flutter-apk/app_name-${{ steps.flutter_version.outputs.version_number }}-${{ steps.flutter_version.outputs.build_number }}.apk --app ${{ secrets.FIREBASE_APP_ID }} --groups rpa-testers --release-notes "New release for version ${{ github.ref }}"

5. Commit and Push

Commit the workflow file to your repository and push it to GitHub. This will trigger the GitHub Actions workflow on your next push to the main branch or when opening a pull request.

Security Considerations

Never commit tokens or sensitive information directly in your code or workflow files.
Regularly rotate your tokens and update the corresponding secrets in GitHub.
Review and limit the permissions granted to your personal access tokens.
Monitor your GitHub Actions usage and review logs for any suspicious activity.

By following these steps, you'll have set up a basic CI/CD pipeline using GitHub Actions, incorporating both GitHub and Firebase authentication for your project.

Blog