CI/CD Pipeline for Flutter Apps Development

Overview

This guide outlines the process of setting up a CI/CD pipeline for a Flutter mobile application using Fastlane, GitHub Actions, and Firebase App Distribution. The pipeline automates building, testing, and distributing the app, streamlining development and ensuring rapid, consistent deployments.

Table of Contents

• Setting Up Flavors in Flutter
• Firebase Configuration
• Installing Fastlane
• Integrating Firebase with Fastlane
• Setting Up GitHub Actions
• Running the Pipeline
• Conclusion
• References

Setting Up Flavors in Flutter

..\.vscode\launch.json Configuration

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "APP_NAME Development",
            "request": "launch",
            "type": "dart",
            "program": "lib/main_development.dart",
            "args": ["--flavor", "Development", "--target", "lib/main_development.dart"]
        },
        {
            "name": "APP_NAME Production",
            "request": "launch",
            "type": "dart",
            "program": "lib/main_production.dart",
            "args": ["--flavor", "Production", "--target", "lib/main_production.dart"]
        }
    ]
}

..\android\app\build.gradle Configuration

flavorDimensions "default"
productFlavors {
    production {
        dimension "default"
        resValue "string", "app_name", "APP_NAME Production"
    }
    development {
        dimension "default"
        applicationIdSuffix ".dev"
        resValue "string", "app_name", "APP_NAME Development"
    }
}

..\android\app\src\main\AndroidManifest.xml Configuration

<application
    android:label="@string/app_name"
    ...>
    ...
</application>

Build Command

flutter run --release -t lib/main_production.dart --flavor production

Firebase Configuration

1. Create a new Firebase project on the Firebase console.

2. Login to Firebase:

   • firebase login

3. Install and configure FlutterFire CLI:

   • dart pub global activate flutterfire_cli
     flutterfire configure
     flutter pub add firebase_core
     flutterfire configure

Installing Fastlane

1. Install Ruby:

   • Ruby Installer

2. Install Fastlane (in cmd):

   • gem install fastlane

3. Initialize Fastlane (in project root):

   • cd android
     fastlane init

Integrating Firebase with Fastlane

1. Add the Firebase App Distribution plugin:

   • fastlane add_plugin firebase_app_distribution

2. Login to Firebase CLI:

   • firebase login:ci

     Save the token for later use.

3. The ..\android\fastlane\Fastfile file will be automatically created, update it with the following:

   • default_platform(:android)
     
     platform :android do
       desc "Lane for Android Firebase App Distribution"
       lane :firebase_distribution do
          sh "flutter clean"
          sh "flutter build apk --release --flavor production --target lib/main_production.dart --no-tree-shake-icons"
          firebase_app_distribution(
            app: "1:383408612193:android:da0f9d86c0a8051e4c5b20",
            firebase_cli_token: ENV["FIREBASE_CLI_TOKEN"],
            android_artifact_type: "APK",
            android_artifact_path: "../build/app/outputs/flutter-apk/app-production-release.apk",
            testers: "[email protected]",
            release_notes: "YOUR_RELEASE_NOTES_HERE"
          )
        end
      end

Setting Up GitHub Actions

1. Secure your data in GitHub Secrets:

   • Firebase options (4 secrets)

     • FIREBASE_OPTIONS_ANDROID_API_KEY
     • FIREBASE_OPTIONS_ANDROID_APP_ID
     • FIREBASE_OPTIONS_IOS_API_KEY
     • FIREBASE_OPTIONS_IOS_APP_ID

   • Fastfile (2 secrets)

     • FIREBASE_CLI_TOKEN
     • APP_ID

2. Create a GitHub Actions workflow file ..\.github\workflows\android_fastlane_firebase_app_distribution_workflow.yml:

   •  name: Android Fastlane with Firebase App Distribution Workflow
      
      on:
        push:
          branches:
            - mobile-app-stable # The branch that you would like to run the workflow when you push into it.
      
      jobs:
        distribute_to_firebase:
          runs-on: ubuntu-latest
          steps:
            - name: Checkout my repo code
              uses: actions/checkout@v2
      
            - name: Set up JDK 11
              uses: actions/setup-java@v2
              with:
                java-version: "11"
                distribution: "temurin"
      
            - name: Install Flutter
              uses: subosito/flutter-action@v2
              with:
                channel: stable
      
            # If there was an error, then run this: "cd android" then "bundle lock --add-platform x86_64-linux"
            - name: Setup Ruby
              uses: ruby/setup-ruby@v1
              with:
                ruby-version: "3.3.4"
                bundler-cache: true
                working-directory: android
      
            - name: Build and Distribute App
              env:
                APP_ID: ${{ secrets.APP_ID }}
                FIREBASE_CLI_TOKEN: ${{ secrets.FIREBASE_CLI_TOKEN }}
                FIREBASE_OPTIONS_ANDROID_API_KEY: ${{ secrets.FIREBASE_OPTIONS_ANDROID_API_KEY }}
                FIREBASE_OPTIONS_ANDROID_APP_ID: ${{ secrets.FIREBASE_OPTIONS_ANDROID_APP_ID }}
                FIREBASE_OPTIONS_IOS_API_KEY: ${{ secrets.FIREBASE_OPTIONS_IOS_API_KEY }}
                FIREBASE_OPTIONS_IOS_APP_ID: ${{ secrets.FIREBASE_OPTIONS_IOS_APP_ID }}
              run: |
                bundle exec fastlane android firebase_distribution
              working-directory: android

Running the Pipeline

1. Push your code to GitHub.
2. GitHub Actions will trigger the workflow on the mobile-app-stable branch.
3. The workflow will build the APK and deploy it to Firebase App Distribution.
4. Testers will receive the APK via Firebase App Distribution.

Now, no more sending APKs via WhatsApp! 😂

Conclusion

Setting up a CI/CD pipeline with Fastlane, GitHub Actions, and Firebase App Distribution can greatly streamline your mobile app development process. It ensures that your code is always in a deployable state, automates repetitive tasks, and enables rapid, consistent releases.

Happy Coding! 🚀

References

• Fastlane Documentation
• GitHub Actions Documentation
• Firebase App Distribution Documentation