Dockerfile

FROM ruby:2.2.7

ENV N_VERSION 2.1.7
ENV NODE_VERSION 8.1.2
ENV PHANTOMJS_VERSION 2.1.1
ENV YARN_VERSION 0.24.6

# Gems with native extensions
RUN apt-get update && apt-get install -y --no-install-recommends \
    build-essential fontconfig curl

# NodeJS
RUN curl -L --output /tmp/n.tar.gz https://github.com/tj/n/archive/v$N_VERSION.tar.gz && \
    cd /tmp && \
    tar xf n.tar.gz && \
    cd n-$N_VERSION && \
    make && \
    n $NODE_VERSION

# PhantomJS
RUN curl --output /usr/local/bin/phantomjs https://s3.amazonaws.com/circle-downloads/phantomjs-$PHANTOMJS_VERSION && \
    chmod +x /usr/local/bin/phantomjs

# Yarn
RUN set -ex \
  && for key in \
    6A010C5166006599AA17F08146C2130DFD2497F5 \
  ; do \
    gpg --keyserver pgp.mit.edu --recv-keys "$key" || \
    gpg --keyserver keyserver.pgp.com --recv-keys "$key" || \
    gpg --keyserver ha.pool.sks-keyservers.net --recv-keys "$key" ; \
  done \
  && curl -fSLO --compressed "https://yarnpkg.com/downloads/$YARN_VERSION/yarn-v$YARN_VERSION.tar.gz" \
  && curl -fSLO --compressed "https://yarnpkg.com/downloads/$YARN_VERSION/yarn-v$YARN_VERSION.tar.gz.asc" \
  && gpg --batch --verify yarn-v$YARN_VERSION.tar.gz.asc yarn-v$YARN_VERSION.tar.gz \
  && mkdir -p /opt/yarn \
  && tar -xzf yarn-v$YARN_VERSION.tar.gz -C /opt/yarn --strip-components=1 \
  && ln -s /opt/yarn/bin/yarn /usr/local/bin/yarn \
  && ln -s /opt/yarn/bin/yarn /usr/local/bin/yarnpkg \
  && rm yarn-v$YARN_VERSION.tar.gz.asc yarn-v$YARN_VERSION.tar.gz