FROM ruby:2.3.4
RUN apt-get update -qq && apt-get install -y build-essential
RUN gem install bundler --version 1.14

# in dev builds, the git root is mapped to the container's /app/
WORKDIR /app

COPY Gemfile Gemfile.lock /app/
RUN bundle config build.nokogiri --use-system-libraries && \
    bundle install --jobs=4
