Create signed Android app. Fastlane + Gradle

create_signed_app.ruby

desc "Create a signed version of the app"
lane :signed_apk do

# get version and build number from git
# https://blog.uncommon.is/using-git-to-generate-versionname-and-versioncode-for-android-apps-aaa9fc2c96af
versionName = sh("git describe --dirty").gsub(/\s+/, "")
# +520 to sync version codes with the previous app.
versionCode = sh("git rev-list --first-parent --count origin/master").gsub(/\s+/, "").to_i + 520
keyPath ="#{sh("pwd").chomp}/keystore.jks"

# build the release variant
gradle(
    task: "assembleRelease",
    print_command: true,
    # Gradle properties
    properties: {
    "android.injected.signing.store.file" => keyPath,
    "android.injected.signing.store.password" => ENV['KEYSTORE_PASSWORD'],
    "android.injected.signing.key.alias" => ENV['KEY_ALIAS'],
    "android.injected.signing.key.password" => ENV['KEY_PASSWORD'],
    "versionCode" => versionCode,
    "versionName" => versionName
    }    
)

puts "Created signed apk. VersionName: #{versionName}. VersionCode: #{versionCode}"

end