FROM ruby:alpine

ENV BUILD_PACKAGES build-base nodejs
ENV RUBY_PACKAGES py-pygments
RUN apk update && \
    apk upgrade && \
    apk add $BUILD_PACKAGES && \
    apk add $RUBY_PACKAGES && \
    rm -rf /var/cache/apk/*

RUN gem install jekyll rdiscount kramdown jekyll-redirect-from rouge

VOLUME /srv/jekyll
EXPOSE 4000

WORKDIR /srv/jekyll
ENTRYPOINT ["jekyll"]