Gitlab CI for react-native builds

.gitlab-ci.yml

image: openjdk:8-jdk
# image: jangrewe/gitlab-ci-android

variables:
  ANDROID_COMPILE_SDK: "23"
  ANDROID_BUILD_TOOLS: "23.0.1"
  ANDROID_SDK_TOOLS: "3859397"

before_script:

    # Fetch the specified SDK tools version to build with
    - wget --quiet --output-document=/tmp/sdk-tools-linux.zip https://dl.google.com/android/repository/sdk-tools-linux-${ANDROID_SDK_TOOLS}.zip
    - unzip /tmp/sdk-tools-linux.zip -d .android

    # Set up environment variables
    - export ANDROID_HOME=$PWD/.android
    - export PATH=$PATH:$PWD/.android/platform-tools/

    # Install platform tools and Android SDK for the compile target
    - echo y | .android/tools/bin/sdkmanager "platforms;android-${ANDROID_COMPILE_SDK}"


    # - curl -sL https://deb.nodesource.com/setup_4.x | bash
    - curl -sL https://deb.nodesource.com/setup_8.x | bash 
    # - apt-get update
    - apt-get install -y nodejs
    # - apt-get install -y build-essential
    # - curl http://npmjs.org/install.sh | sh
    - npm install -g react-native-cli
    - npm i -g yarn
    - yarn
    - react-native link
    - chmod +x android/gradlew

stages:
  - build
  # - test

build:
  stage: build
  script:
    - cd android && ./gradlew assembleDebug
  artifacts:
    paths:
    - android/app/build/outputs/

# unitTests:
#   stage: test
#   script:
#     - ./gradlew test

# functionalTests:
#   stage: test
#   script:
#     - wget --quiet --output-document=android-wait-for-emulator https://raw.githubusercontent.com/travis-ci/travis-cookbooks/0f497eb71291b52a703143c5cd63a217c8766dc9/community-cookbooks/android-sdk/files/default/android-wait-for-emulator
#     - chmod +x android-wait-for-emulator
#     - echo y | android-sdk-linux/tools/android --silent update sdk --no-ui --all --filter sys-img-x86-google_apis-${ANDROID_COMPILE_SDK}
#     - echo no | android-sdk-linux/tools/android create avd -n test -t android-${ANDROID_COMPILE_SDK} --abi google_apis/x86
#     - android-sdk-linux/tools/emulator64-x86 -avd test -no-window -no-audio &
#     - ./android-wait-for-emulator
#     - adb shell input keyevent 82
#     - ./gradlew cAT

hello, can you give me some example for ios?