Introduction

In the world of mobile app development, efficiency and automation are key. FastLane offers a suite of tools designed to automate the deployment of mobile apps, making it an indispensable tool for Flutter developers. This guide will walk you through setting up FastLane for Android and macOS, ensuring a smoother deployment process for your Flutter apps.

Getting Started with FastLane

Install FastLane

1. Android

2. install Ruby

   • you can use RubyInstaller or the following terminal commands
   • make sure to open the terminal as an administrator (Windows users only)

   choco install ruby # you must have Chocolatey package manager 
   gem install bundler
   ruby --version
   

• Install Fastlane

  gem install fastlane
  

• set environment variables

  • open: environment variables form search bar
  • under system variables add those keys and values

    LC_ALL ⇒ en_US.UTF-8
    LANG ⇒ en_US.UTF-8
    FLUTTER_ROOT=<Your flutter root file>

1. macOS

2. install ruby

   • open terminal the write

   brew install ruby && sudo gem install bundler && ruby --version 
   

• Install Fastlane

  Homebrew needs to be installed before executing brew commands, as new macOS users might not have it installed.

  brew install fastlane
  

• set environment variables

  • open: finder then go to the top bar click Go ⇒ home
  • after opening home click cmd&shift&. to see the hidden files then open .zprofile file

  • add those lines to your .zprofile file

    export PATH="/opt/homebrew/opt/ruby/bin:$PATH”
    export LC_ALL=en_US.UTF-8
    export LANG=en_US.UTF-8
    export FLUTTER_ROOT="<Your flutter root file>" # examle /Users/alimaher/fvm/default/
    

FastLane For Android

• Setting up *fastlane*
  • In the Visual Studio Code terminal, navigate to the Android folder cd android
  • then run fastlane init

You'll be asked to confirm that you're ready to begin, and then for a few pieces of information. To get started quickly:

1. Provide the package name for your application when asked (e.g. io.fabric.yourapp)
2. Press enter when asked for the path to your json secret file
3. Answer 'n' when asked if you plan on uploading info to Google Play via fastlane (we can set this up later)

That's it! fastlane will automatically generate a configuration for you based on the information provided.

You can see the newly created ./fastlane directory, with the following files:

• Appfile which defines configuration information that is global to your app
• Fastfile which defines the "lanes" that drive the behavior of fastlane
• Setting up *supply*

supply is a fastlane tool that uploads app metadata, screenshots and binaries to Google Play. You can also select tracks for builds and promote builds to production!

For supply to be able to initialize, you need to have successfully uploaded an APK to your app in the Google Play Console at least once.

Setting it up requires downloading a credentials file from your Google Developers Service Account.

Collect your Google credentials

Tip: If you see Google Play Console or Google Developer Console in your local language, add &hl=en at the end of the URL (before any #...) to switch to English. All the links below already have this to make it easier to find the correct buttons.

Note: if you face issues when following these instructions, you might want to refer to the official documentation by Google.

1. Open the Google Play Console
   1. Click Account Details, and note the Developer Account ID listed there
2. Enable the Google Play Developer API by selecting an existing Google Cloud Project that fits your needs and pushing ENABLE
   1. If you don't have an existing project or prefer to have a dedicated one for fastlane, create a new one here and follow the instructions
3. Open Service Accounts on Google Cloud and select the project you'd like to use
   1. Click the CREATE SERVICE ACCOUNT button at the top of the Google Cloud Platform Console page
   2. Verify that you are on the correct Google Cloud Platform Project by looking for the Developer Account ID from earlier within the light gray text in the second input, preceding .iam.gserviceaccount.com, or by checking the project name in the navigaton bar. If not, open the picker in the top navigation bar, and find the right one.
   3. Provide a Service account name (e.g. fastlane-supply)
   4. Copy the generated email address that is noted below the Service account-ID field for later use
   5. Click DONE (don't click CREATE AND CONTINUE as the optional steps such as granting access are not needed):

6. Click on the **Actions** vertical three-dot icon of the service account you just created
7. Select **Manage keys** on the menu
8. Click **ADD KEY** → **Create New Key**
9. Make sure **JSON** is selected as the `Key type`, and click **CREATE**
10. Save the file on your computer when prompted and remember where it was saved at

1. Open the Google Play Console and select Users and Permissions
   1. Click Invite new users
   2. Paste the email address you saved for later use into the email address field
   3. Click on Account Permissions
   4. Choose the permissions you'd like this account to have. We recommend Admin (all permissions), but you may want to manually select all checkboxes and leave out some of the Releases permissions such as Release to production, exclude devices, and use Play App Signing
   5. Click on Invite User

You can use
 [fastlane run validate_play_store_json_key json_key:/path/to/your/downloaded/file.json](https://docs.fastlane.tools/actions/validate_play_store_json_key/) to test the connection to Google Play Store with the downloaded private key. Once that works, add the path to the JSON file to your Appfile:

json_key_file("path/to/your/play-store-credentials.json")
package_name("my.package.name")

Fetch your app metadata

If your app has been created on the Google Play developer console, you're ready to start using supply to manage it! Run:

fastlane supply init

and all of your current Google Play store metadata will be downloaded to fastlane/metadata/android.

Test and deploy

• internal test

  • open: android/fastlane/Fastfile file, in this file you will add your setting for upload new aab for internal testing.

  default_platform(:android)
  
  # upload to internal test to Google Play
  lane :internal do 
    # build the app bundle if you haven't already 
    gradle(task: 'bundleRelease')
    # Upload to internal test
    upload_to_play_store(
      track: 'internal',
      aab: '../build/app/outputs/bundle/release/app-release.aab', # Update this path if your AAB is generated in a different location
      skip_upload_apk: true,
      skip_upload_images: true,
      skip_upload_screenshots: true,
      skip_upload_metadata: true,
      skip_upload_changelogs: true,
      skip_upload_aab: false,
    )
  end
  
  

  • now increase your build number in pubspec.yaml
  • now in your terminal run the following commands:

  flutter clean
  flutter pub get
  flutter build appbundle
  cd ./android/
  fastlane internal # Now you will push your aab to the internal test
  cd ..
  

  ---

• release

  • open: android/fastlane/Fastfile file, in this file you will add your sitting for upload new aab for internal testing.

  default_platform(:android)
  
  # upload release to Google Play
  lane :release do
    gradle(task: 'bundleRelease')
    # Upload to internal test
    upload_to_play_store(
      track: 'production',
      aab: '../build/app/outputs/bundle/release/app-release.aab', # Update this path if your AAB is generated in a different location
      skip_upload_apk: true,
      skip_upload_images: true,
      skip_upload_screenshots: true,
      skip_upload_metadata: true,
      skip_upload_changelogs: true,
      skip_upload_aab: false,
    )
  end
  

  • now increase your build number in pubspec.yaml
  • now in your terminal run the following commands:

  flutter clean
  flutter pub get
  flutter build appbundle
  cd ./android/
  fastlane release # Now you will push your aab to the internal test
  cd ..
  

  ---

• increase version number automatically

• add script.rb file:

  create new file script.rb in android folder: andoird/script.rb

  this code will edit in your pubspec.yaml file to increase your version

  # pubspec_path = '../pubspec.yaml'
  pubspec_path = File.expand_path('../../pubspec.yaml', __FILE__)
  
  # Read the file into an array of lines
  lines = File.readlines(pubspec_path)
  
  # Find the line containing the version and update it
  lines.map! do |line|
    if line.strip.start_with?('version:')
      if line =~ /(\d+)\.(\d+)\.(\d+)\+(\d+)/
        major, minor, patch, build = $1.to_i, $2.to_i, $3.to_i, $4.to_i
        patch += 1
        build += 1
        line = "version: #{major}.#{minor}.#{patch}+#{build}\n"
      end
    end
    line
  end
  
  # Write the updated lines back to the file
  File.open(pubspec_path, 'w') { |file| file.puts(lines) }
  

• open: android/fastlane/Fastfile file, in this file you will add your sitting for increase your version number automatically

lane :icrease_build_number do
  # script.rb is a ruby script that increments the build number in pubspec.yaml
  system("ruby ../script.rb")
end

• now increase your build number in pubspec.yaml
• now in your terminal run the following commands:

cd ./android/
fastlane icrease_build_number 
cd ..

• you can use both of release or internal and icrease_build_number fastlane action to fully automate your deployment steps using this code:

cd ./android/
fastlane icrease_build_number
cd ..
flutter clean
flutter pub get
flutter build appbundle
cd ./android/
fastlane release # or use internal 
cd ..