\ apt-get install -y nodejs mysql-client --no-install-recommends && \ rm -rf /var/lib/apt/lists/* && \ mkdir -p /usr/src/app WORKDIR /usr/src/app COPY Gemfile /usr/src/app/ COPY Gemfile.lock /usr/src/app/ RUN bundle install COPY . /usr/src/app EXPOSE 3000 CMD ["./bin/rails", "server", "-b", "0.0.0.0"]