With this series of two posts, I’m going to detail how to setup a continuous deployment for an Android app made with React Native. (Bonus: it also works without React Native!).
I will use and configure Fastlane with Github Actions in order to deploy on Playstore at each pre-release or even each commit if you want. This post will be split into two parts:
- Deploy an Android App Bundle on Playstore with Fastlane
- Trigger Fastlane with Github Actions for uploading AAB (Android App Bundle) on Playstore.
In this post, I will use AAB but you can also use APK.
The source code of the application is available in this Github repository: https://github.com/antoinecellier/rn-fastlane-githubactions/
Setting up Fastlane on your machine
Fastlane is an open source platform aimed at simplifying Android and iOS deployment. It lets you automate every aspect of your development and release workflow.
Your workflow will be defined by Ruby files which are called Appfile
and Fastfile
.
The Appfile
stores useful information that are used across all Fastlane tools like your Apple ID or the application Bundle Identifier, to deploy your lanes faster and tailored on your project needs.
The FastFile
contains the Lanes definition. The Lanes are functions that define actions to execute in a sequential way. For example:
update version of the app
-> build the app
-> deploy the app
To install it on your machine, follow these steps in Fastlane documentation: https://docs.fastlane.tools/getting-started/android/setup/
To be sure that Fastlane is correctly installed, just use fastlane --help
in the terminal:
Create a Google Developers service account
The Google Developers Services will be used to upload an Android App Bundle on Playstore.
Follow these steps in Fastlane documentation: https://docs.fastlane.tools/actions/upload_to_play_store/#setup
At the end of these steps, you will have a credentials json file looking like this:
{
"type": "...",
"project_id": "...",
"private_key_id": "...",
"private_key": "...",
"client_email": "...",
"client_id": "...",
"auth_uri": "...",
"token_uri": "...",
"auth_provider_x509_cert_url": "...",
"client_x509_cert_url": "..."
}
Generate a Keystore file in order to sign in the app
If you use Android App Bundles, you need to sign the app bundle before you upload it to the Play Console, and Play App Signing takes care of the rest.
Generate a release.keystore file. 4 mandatory elements are in this file:
- The file itself.
- The key alias (see the keytool command below).
- The keystore password.
- The key password.
$ keytool -genkey -v -keystore release.keystore -alias <your key alias> -keyalg RSA -keysize 2048 -validity 10000
For more information, go to https://developer.android.com/studio/publish/app-signing#generate-key
Before continuing, make sure you have:
- A functional Fastlane on your machine.
- A Google Developer service account with your json credentials file.
- A release.keystore file generated.
Setting up Fastlane
From now on, we will consider that the Android configuration files are generated by React Native init without changes.
Here is how to initialise a React Native app:
$ npx react-native init AwesomeProject
In the Android folder, run:
$ fastlane init
Prompt steps:
- Provide the package name for the application when asked (e.g. com.my.app).
- Press enter when asked for the path to your json secret file.
- Answer 'n' when asked if you plan on uploading info to Google Play via Fastlane (we can set this up later).
Fastlane folder has been created and contains two files:
-
Appfile
which defines global configuration information of the app. -
FastFile
which defines lanes of Fastlane.
The service_account.json
file of your Google Developer service account will be used in AppFile
. Copy the json file inside the Fastlane folder and modify android/fastlane/AppFile
:
json_key_file("fastlane/service_account.json")
package_name("com.my.app")
You can now test the connection to the Google Play Store:
$ fastlane run validate_play_store_json_key json_key:/path/to/your/file.json
Setting up fastlane plugins
Plugins allow reuse fonctions created by the community by installing them from the Fastlane client.
You going to add Fastlane plugins for:
Retrieve the version number of the application in the package.json file that will define the version number of the Android App Bundle. For this, we need to add the load_json plugin:
$ fastlane add_plugin load_json
> Should fastlane modify the Gemfile
at path '/xxx/react-native-app/android/Gemfile' for you? (y/n)
> y
To be uploaded on Playstore, each AAB or APK must have a unique version code. To set the version code of your app, install the versioning_android
plugin:
$ fastlane add_plugin versioning_android
Now let's configure the first lane in the FastFile
file.
The first thing to do is to implement a function that generates a unique versionCode
for the Android App Bundle. Put this function, that generate a new version code, in the upper part of the android/fastlane/FastFile
:
default_platform(:android)
def getVersionCode
# Instead of managing the version code manually it is based on a timestamp in seconds
# Any build done more recently is considered to be a higher version
# versionCode increase every minute (so max 1 build per minute)
# versionCode cannot be smaller than legacyVersionCode
thirtySeptemberTwentyTwenty = 1601480940 / 60
legacyVersionCode = 10902
versionCode = legacyVersionCode + (Time.now.to_i / 60) - thirtySeptemberTwentyTwenty
if versionCode > 2100000000
raise "versionCode cannot be higher than 2100000000"
end
versionCode.floor()
end
...
And define the first lane that will use getVersionCode to update android.defaultConfig.versionCode
in the app/build.gradle
file:
...
platform :android do
desc "Increments internal build number tracking (different than version)"
lane :bump_build_number do
android_set_version_code(
version_code: getVersionCode()
)
end
...
Still in android/fastlane/FastFile
, you can define the lane for building and uploading the Android App Bundle on Playstore.
desc "Build and uploads the app to playstore for a internal testing release"
lane :playstoreInternal do |options|
# Retrieve version of my app in package.json (React Native case)
package = load_json(json_path: "../package.json")
# Clean build folder
gradle(
task: "clean"
)
# Bump android.defaultConfig.versionCode
bump_build_number
# Do the bundle of the application
gradle(
task: 'bundle',
build_type: 'Release',
properties: {
"android.injected.signing.store.file" => Dir.pwd + "/release.keystore",
"android.injected.signing.store.password" => options[:RELEASE_KEYSTORE_PASSWORD], # keystore password
"android.injected.signing.key.alias" => options[:RELEASE_KEYSTORE_ALIAS], # alias
"android.injected.signing.key.password" => options[:RELEASE_KEYSTORE_KEY_PASSWORD], # key password
"vname" => package["version"]
}
)
# Upload Android App Bundle to PlayStore like Internal testing Release
upload_to_play_store(
track: 'internal',
release_status: 'draft', # <http://docs.fastlane.tools/actions/upload_to_play_store/#parameters>
skip_upload_apk: true,
version_name: package["version"]
)
end
Let’s look into details the lane:
- First we retrieve the application version from the
package.json
file
desc "Build and uploads the app to playstore for a internal testing release"
lane :playstoreInternal do |options|
package = load_json(json_path: "../package.json")
- Then clean up the build folder and use
bump_build_number
lane created above:
gradle(
task: "clean"
)
bump_build_number
- Finally, we define a gradle task to build the application in the app/build.gradle file:
gradle(
task: 'bundle',
build_type: 'Release',
properties: {
"android.injected.signing.store.file" => Dir.pwd + "/release.keystore",
"android.injected.signing.store.password" => options[:RELEASE_KEYSTORE_PASSWORD], # keystore password
"android.injected.signing.key.alias" => options[:RELEASE_KEYSTORE_ALIAS], # alias
"android.injected.signing.key.password" => options[:RELEASE_KEYSTORE_KEY_PASSWORD], # key password
"vname" => package["version"]
}
)
4 different properties are needed to allow gradle to sign your application:
-
android.injected.signing.store.file
: Path to the release.keystore file. -
android.injected.signing.store.password
: Keystore password. -
android.injected.signing.key.alias
: Key alias of the release.keystore file. -
android.injected.signing.key.password
: key password.
Three of these properties are sensitive information, so they can be filled through the Fastlane parameters. For example:
$ fastlane playstoreInternal RELEASE_KEYSTORE_PASSWORD:**keystore password**
At this step, you can check if the application is properly bundled. Copy your release.keystore
file in the android/fastlane
folder and run the command below with the passwords and the alias of your release.keystore
file:
$ fastlane playstoreInternal
> RELEASE_KEYSTORE_PASSWORD:**mypassword**
> RELEASE_KEYSTORE_ALIAS:**myalias**
> RELEASE_KEYSTORE_KEY_PASSWORD:**mykeypassword**
If you copy paste the entire file above, comment upload_to_play_store
action in order to just test Gradle build.
The last step of the lane is to upload the aab on Playstore:
upload_to_play_store(
track: 'internal', # 'internal' for internal testing release
release_status: 'draft', # http://docs.fastlane.tools/actions/upload_to_play_store/#parameters>
skip_upload_apk: true, # if you want to upload apk, use skip_upload_aab instead
version_name: package["version"]
)
It's time to test the whole workflow of your awesome lane:
$ fastlane playstoreInternal
> RELEASE_KEYSTORE_PASSWORD:**mypassword**
> RELEASE_KEYSTORE_ALIAS:**myalias**
> RELEASE_KEYSTORE_KEY_PASSWORD:**mykeypassword**
Let's check the result in the Google Play Console.
If you have another way to upload your applications on Playstore or to improve this workflow, please feel free to share it with us.
Source code is available in this repository:
https://github.com/antoinecellier/rn-fastlane-githubactions
In the second part of this post we will see how to use Github Actions in order to upload an Android App Bundle on Playstore at each pre-release.
A big thank you to @eric_briand, @bpetetot and @tbetous for their proofreading.
Sources: