This is the second part of my post “Deploy React Native app on Playstore with Fastlane and Github Actions”.
All the sources of the application used here are available in this Github repository: https://github.com/antoinecellier/rn-fastlane-githubactions

In this part, we are going to set up Github Actions to build and upload an Android App Bundle on Playstore for each pre-release.

Setting up Github secrets

First, we will see how to store sensitive datas in Github secrets in order to use it easily with Github actions.

Encrypt release.keystore file and service_account.json file with GPG.

Github documentation suggests using GPG to encrypt your credentials and store them as Github secrets:
https://docs.github.com/en/actions/reference/encrypted-secrets#limits-for-secrets

You must install GPG on your machine ( https://gnupg.org ), then encrypt these two files:

$ gpg -c --armor release.keystore 
> Enter Passphrase 
$ gpg -c --armor service_account.json 
> Enter Passphrase

Each file encrypted with GPG must have a passphrase associated with it. The passphrase is used for decryption. Once you have done this, two .asc files have been generated. The idea is to store the contents of the .asc files and its passphrase in the secrets of Github.

Store Github secrets

According to the Fastlane configuration and files encrypted, you need to have these data in Github secrets:

• For .keystore file:
  • Content of .keystore.asc (cat .keystore.asc).
  • Passphrase of .keystore.asc for decrypt the file.
  • Password of .keystore file.
  • Alias of .keystore file.
  • Key password of .keystore file.
• For service_account.json ( Playstore service account file ):
  • Content of service_account.json.asc (cat service_account.json.asc).
  • Passphrase of service_account.json.asc for decrypt the file.

On your repository Github page go to Settings > Secrets , and create new secrets for each value above.

Overview of Github secrets needed:

Setting up Github actions

At the root of the application, create a .github/ folder with inside two folders:

• workflows/ folder with inside a file named pre-release.yml.
• scripts/ folder with inside a file named decrypt_android_keys.sh.

.github/ folder with files are available here:
https://github.com/antoinecellier/rn-fastlane-githubactions/tree/main/.github

Let's now take a look at the file .github/scripts/scripts/decrypt_android_keys.sh:

echo "$RELEASE_KEYSTORE" > release.keystore.asc 
gpg -d --passphrase="$RELEASE_KEYSTORE_PASSPHRASE" --batch release.keystore.asc > android/fastlane/release.keystore 

echo "$SERVICE_ACCOUNT" > service_account.json.asc 
gpg -d --passphrase="$SERVICE_ACCOUNT_PASSPHRASE" --batch service_account.json.asc > android/fastlane/service_account.json 

rm release.keystore.asc service_account.json.asc

The role of this file is to decrypt the .keystore.asc and service_account.json.asc files thanks to passphrase.

In .github/workflows/pre-release.yml, you will define your Github actions which trigger the lane for build and upload the Android App Bundle on Playstore. Here is its content:

name: Pre Release 

on: 
 release: 
  types: [prereleased] 

 workflow_dispatch: 

jobs: 
 Build-and-Deploy: 
  runs-on: ubuntu-latest 

  steps: 
   - uses: actions/checkout@v2 
   - name: Decrypt Android keys 
     run: sh ./.github/scripts/decrypt_android_keys.sh 
     env: 
      RELEASE_KEYSTORE: ${{ secrets.RELEASE_KEYSTORE }}              RELEASE_KEYSTORE_PASSPHRASE: ${{ secrets.RELEASE_KEYSTORE_PASSPHRASE }} SERVICE_ACCOUNT: ${{ secrets.SERVICE_ACCOUNT }} 
SERVICE_ACCOUNT_PASSPHRASE: ${{ secrets.SERVICE_ACCOUNT_PASSPHRASE }} 

   - uses: actions/setup-node@v1 
     with: 
      node-version: '10.x' 

   - uses: actions/setup-ruby@v1 
     with: 
      ruby-version: '2.x' 

   - name: Install packages 
     run: | 
         yarn

   - name: Install Fastlane 
      run: gem install fastlane
   - name: Upload to PlayStore 
      run: | 
         cd android 
         fastlane android playstoreInternal RELEASE_KEYSTORE_PASSWORD:${{secrets.RELEASE_KEYSTORE_PASSWORD}} 
 RELEASE_KEYSTORE_KEY_PASSWORD:${{secrets.RELEASE_KEYSTORE_KEY_PASSWORD}} RELEASE_KEYSTORE_ALIAS:${{secrets.RELEASE_KEYSTORE_ALIAS}}

Let's dig in this file. We first define the action’s trigger, in this case on each pre-release.

name: Pre Release 
 on: 
  release: 
   types: [prereleased]

Then, we declare a job named Build-and-Deploy which runs on Ubuntu environment.
The job will execute decrypt_android_keys.sh thanks to Github secrets.

jobs: Build-and-Deploy: 
 runs-on: ubuntu-latest 

 steps: 
  - uses: actions/checkout@v2 
  - name: Decrypt Android keys 
    run: sh ./.github/scripts/decrypt_android_keys.sh 
    env: 
     RELEASE_KEYSTORE: ${{ secrets.RELEASE_KEYSTORE }}               RELEASE_KEYSTORE_PASSPHRASE: ${{ secrets.RELEASE_KEYSTORE_PASSPHRASE }} 
     SERVICE_ACCOUNT: ${{ secrets.SERVICE_ACCOUNT }} 
     SERVICE_ACCOUNT_PASSPHRASE: ${{ secrets.SERVICE_ACCOUNT_PASSPHRASE }}

Once the content of release.keystore.asc and service_account.json.asc decrypted and retrieved, we setup and install Fastlane. To finish, the action run playstoreInternal lane with each parameters needed:

- uses: actions/setup-node@v1
        with:
          node-version: '10.x'

      - uses: actions/setup-ruby@v1
        with:
          ruby-version: '2.x'

      - name: Install packages
        run: |
          yarn

      - name: Install Fastlane
        run: gem install fastlane

      - name: Upload to PlayStore
        run: |
          cd android
          fastlane playstoreInternal   RELEASE_KEYSTORE_PASSWORD:${{secrets.RELEASE_KEYSTORE_PASSWORD}} RELEASE_KEYSTORE_KEY_PASSWORD:${{secrets.RELEASE_KEYSTORE_KEY_PASSWORD}} RELEASE_KEYSTORE_ALIAS:${{secrets.RELEASE_KEYSTORE_ALIAS}}

Push the .github/ folder on your Github repository, and create apre-release to trigger this awesome Github action!

And here's the result 🎉 🚀

If you have any other way to use Fastlane with Github actions or if you see a way to improve what I propose to you, please share it with us.

A big thank you to @eric_briand, @bpetetot and @tbetous for their proofreading.

Sources:

• https://medium.com/@StefMa/how-to-store-a-android-keystore-safely-on-github-actions-f0cef9413784
• https://github.com/features/actions