Couple methods to launch required android emulator using fastlane

AndroidEmulatorFastfile

# Set of lanes for control android emulators
require 'open3'

platform :android do
  # time in seconds, to wait until emulator will finish launching
  emulator_launch_timeout = 600 # 10 mins should be more, than enough for any relevant configuration

  desc "Starts needed emulator, given though 'device_name' option, kills all others and deletes all redundant apks"
  private_lane :prepare_emulator do |options|
    device_name = options[:device_name]
    # this action is info only, needed to distinguish, which emulator failed and not dig very deeply in logs
    sh "echo 'Starting #{device_name}'"
    adb_port = options[:adb_port]
    device_serial = "emulator-#{adb_port}"

    UI.message('Killing any existent emulators on same port')
    # we don't care output of this command, emulator can be not started
    kill_emulator(
      device_serial: device_serial
    )

    # start emulator on separate process
    # following http://stackoverflow.com/questions/21826527/installing-apk-via-adb-hangs-the-emulator
    # TODO make ANDROID_HOME configurable from outside
    start_avd = "#{ENV['ANDROID_HOME']}/emulator/emulator -port #{adb_port} -avd #{device_name} -wipe-data -no-boot-anim -partition-size 1536"
    Process.fork do
      sh(start_avd)
    end

    # waiting until emulator runs completely
    # time in seconds between checks, if emulator came online
    retry_interval = 10
    tries_count = 0

    loop do
      # run with sys.boot_completed http://stackoverflow.com/questions/3634041/detect-when-android-emulator-is-fully-booted
      boot_complete_cmd = "ANDROID_SERIAL=#{device_serial} adb shell getprop sys.boot_completed"
      stdout, _stdeerr, _status = Open3.capture3(boot_complete_cmd)

      output = stdout.to_s.strip
      if output.eql?('1'.to_s)
        UI.success('Emulator Booted!')
        break
      end

      time_spent = tries_count * retry_interval
      unless time_spent < emulator_launch_timeout
        raise "Failed to start emulator #{device_name},
			 it didn't become online after #{time_spent} seconds,
			 last message was: #{output} "
      end

      UI.message('Waiting for emulator to complete boot')
      tries_count += 1
      sleep(retry_interval)
    end
    # disable animations
    adb(command: 'shell settings put global window_animation_scale 0', serial: device_serial)
    adb(command: 'shell settings put global transition_animation_scale 0', serial: device_serial)
    adb(command: 'shell settings put global animator_duration_scale 0', serial: device_serial)
    UI.success("Emulator #{device_name} boot up took #{tries_count * retry_interval} seconds")
  end

  desc 'Kills all emulators, started by this file'
  private_lane :kill_emulator do |options|
    device_serial = options[:device_serial]
    Open3.capture3("ANDROID_SERIAL=#{device_serial} adb emu kill")
  end
end

# More information about multiple platforms in fastlane:
# https://github.com/KrauseFx/fastlane/blob/master/docs/Platforms.md