Flutter Pipeline Demo

A demo Flutter project built to learn and implement a complete, production-style CI/CD pipeline - the same kind of setup senior Flutter engineers build before shipping real apps at scale.

This isn't a feature-rich app on purpose. The focus is the pipeline and workflow around it: branching strategy, environment flavors, code quality gates, automated testing, Fastlane-driven builds, versioning, and signing - with CI/CD automation to follow in Phase 2.

What the app does

A simple counter app with three small features, used as a working test case for the pipeline:

• Counter - increments a count
• Reset button - resets the count back to 0
• Dark mode toggle - switches between light/dark themes
• Displays the current environment (Development / Staging / Production) and its API URL on screen

Branching strategy

• main - stable, production-ready code only
• develop - integration branch where all features are merged and tested before release
• feature/* - one branch per feature or pipeline step, merged into develop via pull request Both main and develop are protected - direct pushes are disabled, all changes go through a pull request.

Environments (Flavors)

The app supports three flavors, each with its own package name, app name, and isolated Firebase project.

Flavor	Package name suffix	Firebase app
dev	.dev	Isolated dev Firebase app
staging	.staging	Isolated staging Firebase app
prod	none	Isolated production Firebase app

Run a specific flavor:

flutter run --flavor dev -t lib/main_dev.dart
flutter run --flavor staging -t lib/main_staging.dart
flutter run --flavor prod -t lib/main_prod.dart

Code quality

• Lint rules enforced via very_good_analysis
• Formatting enforced via dart format
• Pre-commit hooks via Lefthook - commits are blocked automatically if formatting or analyzer checks fail Run manually:

flutter analyze
dart format .

Testing

Widget tests cover the app's core features (counter increment, reset, theme toggle).

flutter test
flutter test --coverage

Build automation (Fastlane)

Fastlane lanes live in android/fastlane/Fastfile.

Lane	What it does
bump_version	Auto-increments the build number in pubspec.yaml
beta	Bumps version, builds a debug APK for the dev flavor
release	Bumps version, builds a signed release APK for the dev flavor

Run from the android folder:

cd android
fastlane beta
fastlane release

Signing

Release builds are signed using a dedicated keystore, kept outside the repo and never committed.

• Keystore path and credentials are stored in android/key.properties - excluded from git via .gitignore
• Signing config is wired into android/app/build.gradle.kts and applied to the release build type Note: key.properties and .jks / .keystore files are intentionally gitignored. You will need to generate your own keystore locally to build release APKs - see the setup guide below.

Local setup

1. Clone the repo and install dependencies:

git clone <this-repo-url>
cd flutter_pipeline_demo
flutter pub get

2. Install Lefthook hooks:

lefthook install

3. Set up Firebase (requires FlutterFire CLI):

flutterfire configure --project=<your-firebase-project-id> --out=lib/firebase_options_dev.dart --android-package-name=com.example.flutter_pipeline_demo.dev

Repeat for staging and prod with their respective package names.

4. Generate a signing keystore for release builds:

keytool -genkey -v -keystore <path-to-keystore>.jks -keyalg RSA -keysize 2048 -validity 10000 -alias upload

Then create android/key.properties with your keystore path and passwords. This file is never committed.

5. Run the app:

flutter run --flavor dev -t lib/main_dev.dart

Project status

Phase 1 - Foundation and Local Automation: Complete

• Git strategy (branches, protection rules)
• Flavors and per-flavor Firebase setup
• Code quality gates (lint and pre-commit hooks)
• Testing baseline
• Fastlane install
• Versioning automation
• Signing setup

Phase 2 - CI/CD and Full Automation: In progress

• CI/CD platform setup (GitHub Actions or Codemagic)
• PR gate workflow (auto-run analyze, test, format)
• Auto-deploy to Firebase App Distribution, TestFlight, and Play Console
• Secrets management in CI
• Store metadata automation
• Notifications (Slack or Discord)
• Crash monitoring
• End-to-end dry run

CI/CD Secrets

The following secrets are configured in GitHub Actions (Settings > Secrets and variables > Actions):

• FIREBASE_SERVICE_ACCOUNT - Firebase service account JSON for automated uploads
• KEYSTORE_BASE64 - Base64-encoded Android signing keystore
• KEYSTORE_PASSWORD - Keystore password
• KEY_PASSWORD - Signing key password
• KEY_ALIAS - Signing key alias

None of these values are stored in the repository itself.

Notes

This project was built as a learning exercise, documenting real mistakes and fixes along the way rather than a polished, error-free process - including branch mix-ups, environment and keystore path issues, and JDK version conflicts, all resolved and documented as part of the process.