How to Distribute Your Flutter Project Using Firebase App Distribution

Firebase recently launched the alternative to TestFlight and Fabric. Many developers are trying this tool out and so am I. Having worked with it for a while, I decided to show you how to set it up. 

From this short guide, you’ll learn how to set CI/CD for Flutter using Fastlane and Firebase App Distribution.

Note: To understand everything that happens here, you should know how to set up Flutter and how to plug in Firebase. On top of that, this guide describes how to build a project for Android and iOS. So, you’ll need macOS for these tasks. 

1. Installing Flutter

The first thing to do is to install Flutter. 

Then, you should create a Flutter project and a project in Firebase Console.

Now, it’s time to dive into the package manager. Follow this link and install the latest version. 

Use the following line:

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

And then:

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brew install ruby 

After the command is executed, you’ll get the following message:

The next step is to execute the specified command. The last command may differ depending on the macOS version. 

For Catalina, if you need to have Ruby first in your PATH, run:

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echo 'export PATH="/usr/local/opt/ruby/bin:$PATH"' >> ~/.zshrc

Or you can open your .zshrc file and add the following lines:

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export PATH="/usr/local/opt/ruby/bin:$PATH"

export LDFLAGS="-L/usr/local/opt/ruby/lib"

export CPPFLAGS="-I/usr/local/opt/ruby/include"

Here is how my file looks like after that:

2. Installing Fastlane

Type the following command to install Fastlane:

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xcode-select --install

And then:

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brew cask install fastlane

Open the specified file and add there:

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export PATH="$HOME/.fastlane/bin:$PATH"

In my case, the installation wasn’t a success and I got installed the 2.28.3 version instead of the latest. I turned to this issue to solve my problem.

I tried two options and installed everything successfully following the instruction.

You can also download a ZIP file here.

Setting Up Fastlane

It’s also possible to use Gradle for Android, but it’s better to use Fastlane for iOS. 

Getting Started With Android

Open your Flutter project in the console and go to the Android folder using this command:

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cd android

Then:

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fastlane init

As you see, you should type the name of a package. You can find it in the following file:

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AndroidManifest.xml package=

project_name/android/app/src/main/AndroidManifest.xml

Just press Enter and wait until the full initialization of Fastlane. 

In the end, you’lol see that Fastlane created the following files: 

The next thing you should do is set up Firebase App Distribution following this instruction. 

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curl -sL firebase.tools | bash

firebase login

firebase list

If you see the list of your projects after executing the final command, it means that everything works just fine. 

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fastlane add_plugin firebase_app_distribution

Change your Fastfile file to:

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platform :android do

   desc "New Build to App Distribution Beta"

   lane :beta_app_distribution do

        gradle(task: "clean assembleRelease")

       firebase_app_distribution(

           app: ENV["APPID"],

           firebase_cli_path: "/usr/local/bin/firebase",

           apk_path: "../build/app/outputs/apk/release/app-release.apk"

       )

   end

end

Then, create a file in the Fastlane folder and name it .env.default. 

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PROJECT_NAME=Name your project

CONFIGURATION=Release

APPID=1:17448389999:android:902a57811128931a5d78a1

Where APPID is the ID of your project in Firebase. 

And run the command: 

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fastlane beta_app_distribution 

If you don’t have Java 8 installed, you can download it from Oracle website. 

Or use the following commands: 

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# add open jdk repo

brew tap adoptopenjdk/openjdk

# see available versions

brew search openjdk

# install specific version

brew cask install adoptopenjdk8

Set JAVA_HOME.

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export JAVA_HOME=/Library/Java/JavaVirtualMachines/adoptopenjdk-8.jdk/Contents/Home

export PATH=$JAVA_HOME/bin:$PATH

Once everything is completed, you’ll see the build in the Firebase console and the following inscription in terminal: 

Getting Started With iOS

Open the terminal and enter:

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cd ios

fastlane init

Then, enter your Apple ID and two-factor authorization code, if any.

Create a file in the Fastlane folder and name it .env.default. 

Paste the following data in there:

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PROJECT_NAME=App Name

SCHEME=Runner

CONFIGURATION=Release

CRASHLYTICS_GROUPS=qa_team

CERTIFICATE_PATH=./fastlane/credentials/Certificates.p12

INFO_PLIST_PATH=Runner/Info.plist

ENVIRONMENT=DEVELOPMENT

APPID=1:188999999994:ios:f1cdb1234fdd1d56484ee1 

GOOGLE_APPLICATION_CREDENTIALS=./fastlane/credentials/private-key.json

Again, APPID is the ID of your project in Firebase.

You should also generate p12 certificate. 

To get GOOGLE_APPLICATION_CREDENTIALS, hit the button as seen in the picture below and generate the key.

Appfile:

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app_identifier "com.example.ios" # The bundle identifier of your app

apple_id "appleid@gmail.com" # Your Apple email address

itc_team_id "123456789"

team_id "99D0P2SS1M"

# For more information about the Appfile, see:

#     https://docs.fastlane.tools/advanced/#appfile

Fastfile:

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default_platform(:ios)

platform :ios do

   desc "New Build to App Distribution Beta"

   lane :beta_app_distribution do

      build_ios_app(

             clean: true,

             workspace: 'Runner.xcworkspace',

             scheme: 'Runner',

             export_method: 'ad-hoc'

       )

       firebase_app_distribution(

           app: ENV["APPID"],

           testers: "name.cr@gmail.com",

           firebase_cli_path: "/usr/local/bin/firebase",

       )

   end

end

Now, add the Firebase App Distribution plugin calling this command: 

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fastlane add_plugin firebase_app_distribution

Before building the project via Fastlane, run this command:

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flutter build ios 

And after a successful build run this one: 

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bundle exec fastlane beta_app_distribution 

he application is being built and will be sent to Firebase App Distribution. 

Then, you should accept the invitation in your email and you may start testing your iOS and Android applications.