Dockerfile

FROM ruby:2.4.4-alpine3.6

WORKDIR /janna

ARG BUILD_DEPS=' \
    ruby-dev \
    build-base \
    libxml2-dev \
    libxslt-dev \
    libffi-dev'

ARG RUNTIME_DEPS=' \
    curl'

ENV LANG C.UTF-8

RUN apk add --no-cache $RUNTIME_DEPS

COPY Gemfile.lock .
COPY Gemfile .

RUN apk add --no-cache --virtual .build-deps $BUILD_DEPS && \
    bundle install --jobs=4 --retry=4 && \
    apk del .build-deps && \
    rm -rf /var/cache/apk/*

COPY . .

ENTRYPOINT ["bundle", "exec"]
CMD ["shotgun", "--server", "puma", "--host", "0.0.0.0", "--port", "4567"]