CircleCIでRailsアプリをAmazon ECRにpushする ref: http://qiita.com/Jey/items/1bf98d19a5a1e6392bc7

circle.yml

machine:
  services:
    - docker
  timezone:
    Asia/Tokyo
  environment:
    CIRCLE_ENV: test
dependencies:
  pre:
    - if [[ -e ~/docker/ruby.tar ]]; then docker load --input ~/docker/ruby.tar; fi
    - if [[ -e ~/docker/awesome-app-$CIRCLE_BRANCH.tar ]]; then docker load --input ~/docker/awesome-app-$CIRCLE_BRANCH.tar; fi
    - bundle --path=vendor/bundle
    - bundle exec rake assets:precompile
  cache_directories:
    - "~/docker"
    - "vendor/bundle"
    - "public/assets"
  override:
    - docker info
    - docker build -t $DOCKER_REPOS/awesome-app:$CIRCLE_BRANCH .
    - mkdir -p ~/docker
    - docker save -o ~/docker/ruby.tar ruby
    - docker save -o ~/docker/awesome-app-$CIRCLE_BRANCH.tar $DOCKER_REPOS/awesome-app:$CIRCLE_BRANCH
database:
  override:
    - bundle exec rake db:create db:schema:load db:migrate rake db:seed_fu
test:
  override:
    - bundle exec rubocop
    - bundle exec rspec
deployment:
  hub:
    branch: /^(master|staging)$/
    commands:
      - $(aws ecr get-login --region $AWS_REGION)
      - docker push $DOCKER_REPOS/awesome-app:$CIRCLE_BRANCH