Build Process

This guide covers the complete build process for deploying Lumo to production, including optimization, signing, and automation.

Build Configuration

Environment Setup

Production Configuration

class AppConfig {
  static const bool isProduction = bool.fromEnvironment(
    'PRODUCTION',
    defaultValue: false,
  );

  static const bool enableAnalytics = bool.fromEnvironment(
    'ENABLE_ANALYTICS',
    defaultValue: isProduction,
  );

  static const bool enableCrashReporting = bool.fromEnvironment(
    'ENABLE_CRASH_REPORTING',
    defaultValue: isProduction,
  );

  static const String apiBaseUrl = String.fromEnvironment(
    'API_BASE_URL',
    defaultValue: isProduction
        ? 'https://api.yourapp.com'
        : 'https://api-dev.yourapp.com',
  );

  static const String firebaseProjectId = String.fromEnvironment(
    'FIREBASE_PROJECT_ID',
    defaultValue: 'your-app-production',
  );
}

Build Flavors Configuration

import 'package:flutter/foundation.dart';
import 'core/config/app_config.dart';

void main() {
  // Configure based on build mode
  if (kDebugMode) {
    // Debug configuration
    setupDebugMode();
  } else {
    // Production configuration
    setupProductionMode();
  }

  runApp(const MyApp());
}

void setupProductionMode() {
  // Disable debug prints
  debugPrint = (String? message, {int? wrapWidth}) {};

  // Enable crash reporting
  if (AppConfig.enableCrashReporting) {
    FlutterError.onError = (details) {
      // Send to crash reporting service
      FirebaseCrashlytics.instance.recordFlutterError(details);
    };
  }
}

void setupDebugMode() {
  // Keep debug prints enabled
  // Disable analytics in debug
}

Android Production Build

1. Signing Configuration

Generate Release Keystore

# Create release keystore (keep secure!)
keytool -genkey -v \
  -keystore android/app/release-keystore.jks \
  -keyalg RSA \
  -keysize 2048 \
  -validity 10000 \
  -alias release-key

# Example values:
# First and Last Name: Your App Name
# Organizational Unit: Mobile Development
# Organization: Your Company
# City: Your City
# State: Your State/Province
# Country Code: US
# Password: Use a strong password!

Configure Signing

Create android/key.properties:

storePassword=your_store_password
keyPassword=your_key_password
keyAlias=release-key
storeFile=release-keystore.jks

Update android/app/build.gradle.kts:

import java.util.Properties
import java.io.FileInputStream

// Load keystore properties
val keystoreProperties = Properties()
val keystorePropertiesFile = rootProject.file("key.properties")
if (keystorePropertiesFile.exists()) {
    keystoreProperties.load(FileInputStream(keystorePropertiesFile))
}

android {
    namespace = "com.yourcompany.yourapp"
    compileSdk = 34

    defaultConfig {
        applicationId = "com.yourcompany.yourapp"
        minSdk = 23
        targetSdk = 34
        versionCode = flutter.versionCode
        versionName = flutter.versionName

        // ProGuard configuration for release builds
        proguardFiles(
            getDefaultProguardFile("proguard-android-optimize.txt"),
            "proguard-rules.pro"
        )
    }

    signingConfigs {
        create("release") {
            keyAlias = keystoreProperties["keyAlias"] as String
            keyPassword = keystoreProperties["keyPassword"] as String
            storeFile = file(keystoreProperties["storeFile"] as String)
            storePassword = keystoreProperties["storePassword"] as String
        }
    }

    buildTypes {
        release {
            isMinifyEnabled = true
            isShrinkResources = true
            signingConfig = signingConfigs.getByName("release")

            // Add build config fields
            buildConfigField("boolean", "ENABLE_LOGGING", "false")
            buildConfigField("String", "BUILD_TIME", "\"${System.currentTimeMillis()}\"")
        }

        debug {
            applicationIdSuffix = ".debug"
            versionNameSuffix = "-debug"
            buildConfigField("boolean", "ENABLE_LOGGING", "true")
        }
    }
}

2. ProGuard Configuration

Create android/app/proguard-rules.pro:

# Keep Flutter wrapper
-keep class io.flutter.app.** { *; }
-keep class io.flutter.plugin.** { *; }
-keep class io.flutter.util.** { *; }
-keep class io.flutter.view.** { *; }
-keep class io.flutter.** { *; }
-keep class io.flutter.plugins.** { *; }

# Keep Firebase
-keep class com.google.firebase.** { *; }
-keep class com.google.android.gms.** { *; }

# Keep Realm
-keep class io.realm.** { *; }
-dontwarn io.realm.**

# Keep crypto libraries
-keep class javax.crypto.** { *; }
-keep class java.security.** { *; }

# Keep app-specific classes
-keep class com.yourcompany.yourapp.** { *; }

# Remove logging in release
-assumenosideeffects class android.util.Log {
    public static *** d(...);
    public static *** v(...);
    public static *** i(...);
}

3. Build Commands

App Bundle (Recommended for Play Store)

# Clean previous builds
flutter clean
flutter pub get

# Build optimized app bundle
flutter build appbundle \
  --release \
  --obfuscate \
  --split-debug-info=build/debug-info \
  --dart-define=PRODUCTION=true \
  --dart-define=ENABLE_ANALYTICS=true \
  --dart-define=FIREBASE_PROJECT_ID=your-production-project

# Output: build/app/outputs/bundle/release/app-release.aab

APK Build

# Build release APK
flutter build apk \
  --release \
  --obfuscate \
  --split-debug-info=build/debug-info \
  --dart-define=PRODUCTION=true

# Build split APKs by ABI (smaller downloads)
flutter build apk \
  --release \
  --split-per-abi \
  --obfuscate \
  --split-debug-info=build/debug-info

4. Verify Android Build

# Check APK/AAB contents
aapt dump badging build/app/outputs/bundle/release/app-release.aab

# Test installation
adb install build/app/outputs/flutter-apk/app-release.apk

# Check app size
ls -lh build/app/outputs/flutter-apk/app-release.apk

iOS Production Build

1. Xcode Configuration

App Store Connect Configuration

Open ios/Runner.xcworkspace in Xcode
Select “Runner” project
In “Signing & Capabilities”:
- Team: Select your Apple Developer team
- Bundle Identifier: com.yourcompany.yourapp
- Provisioning Profile: App Store (automatic)

Build Settings

#include "Generated.xcconfig"

// Production configuration
FLUTTER_BUILD_MODE=release
DART_DEFINES=PRODUCTION=true,ENABLE_ANALYTICS=true,FIREBASE_PROJECT_ID=your-production-project

// Optimization
ENABLE_BITCODE=NO
STRIP_INSTALLED_PRODUCT=YES
COPY_PHASE_STRIP=YES
DEBUG_INFORMATION_FORMAT=dwarf-with-dsym

// Security
GCC_GENERATE_DEBUGGING_SYMBOLS=YES
GCC_OPTIMIZATION_LEVEL=s
SWIFT_OPTIMIZATION_LEVEL=-O

2. Build Commands

Build for App Store

# Clean previous builds
flutter clean
flutter pub get

# Build iOS release
flutter build ios \
  --release \
  --obfuscate \
  --split-debug-info=build/debug-info \
  --dart-define=PRODUCTION=true \
  --dart-define=ENABLE_ANALYTICS=true

Archive in Xcode

Open ios/Runner.xcworkspace
Select “Any iOS Device (arm64)” or connected device
Product → Archive
When archive completes, select “Distribute App”
Choose “App Store Connect”
Upload to TestFlight/App Store

3. Automated iOS Build (CI/CD)

name: iOS Build
on:
  push:
    tags:
      - 'v*'

jobs:
  build:
    runs-on: macos-latest
    steps:
      - uses: actions/checkout@v3

      - name: Setup Flutter
        uses: subosito/flutter-action@v2
        with:
          flutter-version: '3.8.1'

      - name: Install dependencies
        run: flutter pub get

      - name: Build iOS
        run: |
          flutter build ios \
            --release \
            --obfuscate \
            --split-debug-info=build/debug-info \
            --dart-define=PRODUCTION=true

      - name: Archive with Xcode
        run: |
          cd ios
          xcodebuild -workspace Runner.xcworkspace \
            -scheme Runner \
            -configuration Release \
            -archivePath Runner.xcarchive \
            archive

      - name: Export IPA
        run: |
          cd ios
          xcodebuild -exportArchive \
            -archivePath Runner.xcarchive \
            -exportPath ../build/ios \
            -exportOptionsPlist ExportOptions.plist

Build Optimization

1. Code Optimization

Remove Debug Code

// Use kDebugMode for debug-only code
if (kDebugMode) {
  print('Debug information');
  // Debug-only widgets
}

// Use assertions for development checks
assert(() {
  // Development-only validation
  return true;
}());

Asset Optimization

# Optimize images before building
find assets -name "*.png" -exec pngquant --force --ext .png {} \;

# Optimize SVG files
find assets -name "*.svg" -exec svgo {} \;

2. Build Size Analysis

Android APK Analysis

# Analyze APK size breakdown
flutter build apk --analyze-size

# Use bundletool for AAB analysis
bundletool build-apks \
  --bundle=build/app/outputs/bundle/release/app-release.aab \
  --output=app.apks

bundletool get-size total --apks=app.apks

iOS Size Analysis

# Build with size analysis
flutter build ios --analyze-size

# Xcode size report
# Product → Archive → Distribute App → App Store Connect → Upload
# View size report in App Store Connect

3. Performance Optimization

Dart/Flutter Optimizations

# pubspec.yaml - Remove unused dependencies
dependencies:
  flutter:
    sdk: flutter
  # Only include necessary packages

dev_dependencies:
  # Only development tools

Platform-Specific Optimizations

Android:

android {
    buildTypes {
        release {
            // Enable R8 full mode
            isMinifyEnabled = true
            isShrinkResources = true

            // Optimize DEX files
            multiDexEnabled = false
        }
    }
}

iOS:

// Optimize Swift compilation
SWIFT_OPTIMIZATION_LEVEL = -O
SWIFT_COMPILATION_MODE = wholemodule

// Enable app thinning
ENABLE_APP_SLICING = YES

Automated Build Pipeline

1. GitHub Actions Workflow

name: Build and Release

on:
  push:
    tags:
      - 'v*'

env:
  FLUTTER_VERSION: '3.8.1'

jobs:
  build-android:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v3

      - name: Setup Java
        uses: actions/setup-java@v3
        with:
          distribution: 'zulu'
          java-version: '11'

      - name: Setup Flutter
        uses: subosito/flutter-action@v2
        with:
          flutter-version: ${{ env.FLUTTER_VERSION }}
          cache: true

      - name: Get dependencies
        run: flutter pub get

      - name: Run tests
        run: flutter test

      - name: Decode keystore
        run: |
          echo "${{ secrets.KEYSTORE_BASE64 }}" | base64 -d > android/app/keystore.jks
          echo "storeFile=keystore.jks" >> android/key.properties
          echo "storePassword=${{ secrets.KEYSTORE_PASSWORD }}" >> android/key.properties
          echo "keyPassword=${{ secrets.KEY_PASSWORD }}" >> android/key.properties
          echo "keyAlias=${{ secrets.KEY_ALIAS }}" >> android/key.properties

      - name: Build AAB
        run: |
          flutter build appbundle \
            --release \
            --obfuscate \
            --split-debug-info=build/debug-info \
            --dart-define=PRODUCTION=true \
            --dart-define=ENABLE_ANALYTICS=true

      - name: Upload AAB artifact
        uses: actions/upload-artifact@v3
        with:
          name: app-release.aab
          path: build/app/outputs/bundle/release/app-release.aab

  build-ios:
    runs-on: macos-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v3

      - name: Setup Flutter
        uses: subosito/flutter-action@v2
        with:
          flutter-version: ${{ env.FLUTTER_VERSION }}
          cache: true

      - name: Get dependencies
        run: flutter pub get

      - name: Install CocoaPods
        run: cd ios && pod install

      - name: Build iOS
        run: |
          flutter build ios \
            --release \
            --obfuscate \
            --split-debug-info=build/debug-info \
            --dart-define=PRODUCTION=true

2. Build Scripts

Android Build Script

#!/bin/bash
set -e

echo "Building Android release..."

# Clean previous builds
flutter clean
flutter pub get

# Run tests
flutter test

# Build app bundle
flutter build appbundle \
  --release \
  --obfuscate \
  --split-debug-info=build/debug-info \
  --dart-define=PRODUCTION=true \
  --dart-define=ENABLE_ANALYTICS=true \
  --dart-define=FIREBASE_PROJECT_ID=$FIREBASE_PROJECT_ID

echo "Android build complete!"
echo "Output: build/app/outputs/bundle/release/app-release.aab"

# Optional: Upload to Play Console
if [ "$UPLOAD_TO_PLAY_CONSOLE" = "true" ]; then
  echo "Uploading to Play Console..."
  # Use Google Play Developer API or fastlane
fi

iOS Build Script

#!/bin/bash
set -e

echo "Building iOS release..."

# Clean previous builds
flutter clean
flutter pub get

# Install CocoaPods
cd ios && pod install && cd ..

# Run tests
flutter test

# Build iOS
flutter build ios \
  --release \
  --obfuscate \
  --split-debug-info=build/debug-info \
  --dart-define=PRODUCTION=true \
  --dart-define=ENABLE_ANALYTICS=true

echo "iOS build complete!"
echo "Next: Archive in Xcode and upload to App Store Connect"

Build Verification

1. Pre-Release Testing

Automated Tests

# Run all tests before building
flutter test
flutter test integration_test/

# Performance testing
flutter drive --target=test_driver/app.dart

Manual Testing Checklist

2. Security Validation

Code Obfuscation Verification

# Verify obfuscation worked
unzip -l build/app/outputs/bundle/release/app-release.aab | grep classes
# Should show obfuscated class names

Certificate Verification

# Android: Verify signing
jarsigner -verify -verbose -certs build/app/outputs/bundle/release/app-release.aab

# iOS: Verify provisioning profile
security cms -D -i ios/Runner/embedded.mobileprovision

Troubleshooting

Common Build Issues

Android Issues

# Issue: Build fails with "execution failed for task"
# Solution: Clean and rebuild
flutter clean
cd android && ./gradlew clean && cd ..
flutter pub get
flutter build appbundle --release

# Issue: ProGuard errors
# Solution: Update proguard-rules.pro with keep rules

iOS Issues

# Issue: Code signing errors
# Solution: Check provisioning profiles and certificates
# Xcode → Preferences → Accounts → Download Manual Profiles

# Issue: Pod install fails
# Solution: Update CocoaPods
cd ios
rm -rf Pods Podfile.lock
pod install --repo-update
cd ..

Next Steps

Android Deployment - Deploy to Google Play
iOS Deployment - Deploy to App Store
Distribution - Alternative distribution methods

Your production builds are now ready for deployment! 🚀