FROM ruby:alpine AS base WORKDIR /app RUN <<EOT gem update --system --no-document gem install -N bundler apk update apk upgrade --no-cache EOT RUN mkdir -p /run/app FROM base AS build RUN <<EOT apk add gcc musl-dev ruby-dev make EOT COPY Gemfile* . RUN <<EOT bundle config set --local without development bundle install EOT FROM build AS dev WORKDIR /app RUN <<EOT bundle install EOT CMD [ "sleep", "infinity" ] FROM base # RUN useradd ruby --home /app --shell /bin/sh RUN adduser ruby -h /app -D RUN mkdir -p /run/app RUN chown ruby:ruby /run/app USER ruby:ruby COPY --from=build /usr/local/bundle /usr/local/bundle COPY --from=build --chown=ruby:ruby /app /app COPY --chown=ruby:ruby . . EXPOSE 4567 CMD [ "bundle", "exec", "rackup", "--host", "0.0.0.0", "--port", "4567" ]