Seamless Flutter App Deployment: Automate Android Releases with GitHub Actions, Fastlane, and Firebase App Distribution 🚀

In this guide, we will walk you through the steps to automate the deployment of a Flutter Android app using GitHub Actions and Fastlane, distributing it via Firebase App Distribution. This setup will streamline your workflow, ensuring that every push to your main branch results in a new build being distributed to your testers automatically.

Prerequisites

• A Flutter app project.
• A Firebase project set up with Firebase App Distribution.
• A GitHub repository for your Flutter app.
• Fastlane installed: gem install fastlane (or brew install fastlane on macOS).
• GitHub Actions enabled for your repository.

If you are new to Fastlane, refer to my previous article on setting up Fastlane with Firebase App Distribution for detailed instructions: Publishing Flutter Builds with Fastlane and Firebase App Distribution 🚀

Set Up GitHub Actions

Create a GitHub Actions workflow file. In your GitHub repository, navigate to .github/workflows and create a new file named flutter.yml:

name: Flutter Firebase CI
on:
  push:
    branches:
      - main
jobs:
  build:
    runs-on: ubuntu-latest
    env:
      LC_ALL: en_US.UTF-8
    steps:
      - name: Checkout repository
        uses: actions/checkout@v3
      - name: Set up JDK 11
        uses: actions/setup-java@v3
        with:
          distribution: 'zulu'
          java-version: '11'
      - name: Set up Flutter
        uses: subosito/flutter-action@v2
        with:
          channel: 'stable'
      - name: Install dependencies
        run: flutter pub get
      - name: Run tests
        run: flutter test
      - name: Set up Ruby
        uses: ruby/setup-ruby@v1
        with:
          ruby-version: '3.3' # Specify your ruby version here
      - name: Install Fastlane
        run: gem install fastlane
      - name: Install Fastlane Firebase App Distribution plugin
        working-directory: android
        run: fastlane add_plugin firebase_app_distribution
      - name: Configure Google Application Credentials
        run: echo "${{ secrets.GOOGLE_APPLICATION_CREDENTIALS }}" > $HOME/gcp-key.json
        
      - name: Run Fastlane for Android
        working-directory: android
        run: fastlane distribute
        env:
          GOOGLE_APPLICATION_CREDENTIALS: ${{ secrets.GOOGLE_APPLICATION_CREDENTIALS }}

This workflow file does the following:

• Triggers on every push to the main branch.
• Sets up JDK 11 and Flutter.
• Installs dependencies, run the tests, and builds the APK.
• Sets up Fastlane and deploys the app to Firebase App Distribution.

Generating Google Services Credentials

For the GitHub Actions workflow to deploy your app, it needs access to your Google Services JSON file. Generate a Google Services JSON by:

• Go to https://console.firebase.google.com/
• Select project
• Navigate to Project Settings > Service Accounts

Firebase Project Settings

• Click on Manage Service Account Permissions
• It will redirect to the Google Cloud Console
• Click on Create Service Account

• Enter Service Account Name (This can be any name of your choice)

• Click on CREATE AND CONTINUE
• Select role as Firebase App Distribution Admin

• Click on Done
• Navigate to Service Accounts
• Select the Service Account you just created

• Navigate to the Keys Tab
• Click on ADD KEY
• Select Create New Key
• Choose Key Type as JSON and click on create
• The JSON file will be downloaded to your system
• Keep the file safe

Add Google Services JSON to GitHub Secrets

The downloaded JSON file is required for Firebase services. Follow these steps to securely include its contents in your GitHub Actions workflow:

• Open the downloaded JSON file file in a text editor.
• Copy the entire content of the file.
• Go to your GitHub repository.
• Click on Settings.
• Navigate to Secrets > Actions.
• Click on New repository secret.
• Add GOOGLE_APPLICATION_CREDENTIALS as the name and paste the copied content as the value.

Modify FastFile

After setting up Fastlane following the previous article, navigate to android/fastlane and open Fastfile. Modify the Fastfile to include the credentials for deploying to Firebase App Distribution:

Add the following line:

service_credentials_json_data: ENV['GOOGLE_APPLICATION_CREDENTIALS']

So, the modified FastFile looks like:

platform :android do
    desc "My awesome app"
    lane :distribute do
        build_android_app(
        task: "assemble",
        build_type: "Release")
        # build_android_app is a built-in fastlane action.
        release = firebase_app_distribution(
            service_credentials_json_data: ENV['GOOGLE_APPLICATION_CREDENTIALS'],
            app: "1:123456789:android:abcd1234",
            testers: "tester1@company.com, tester2@company.com",
            release_notes: "Lots of amazing new features to test out!",
            android_artifact_type: "APK",
            android_artifact_path: "../build/app/outputs/apk/uat/release/app-release.apk",
        )
    end
end

Now with every push on main branch, it will run the pipeline with

Conclusion

With these steps, you have set up a continuous deployment pipeline for your Flutter Android app using GitHub Actions and Fastlane, distributing it via Firebase App Distribution. This automation will save you time and effort, allowing you to focus more on development and less on manual deployments.

By integrating these powerful tools, you can ensure that your testers always have access to the latest version of your app, keeping your feedback loop tight and your development process efficient.

For more detailed instructions on setting up Fastlane, refer to my previous article: Publishing Flutter Builds with Fastlane and Firebase App Distribution 🚀

Thanks for reading it! If there’s any mistake, please let me know in the comments so that I can improve. Clap 👏 if this blog helps you!