Dockerfile

FROM ruby:3.3.0-alpine as Builder
ENV APP_HOME="/var/lib/truemail-rack" \
    TMP="/var/lib/truemail-rack/tmp"
RUN apk add --virtual build-dependencies git && \
    git clone https://github.com/truemail-rb/truemail-rack.git $TMP -q && \
    cd $TMP && git checkout v0.10.0 -q && \
    mv app config config.ru .ruby-version Gemfile* $APP_HOME && rm -rf $TMP && \
    apk del build-dependencies
WORKDIR $APP_HOME
RUN gem i bundler -v $(tail -1 Gemfile.lock | tr -d ' ')
RUN apk add --virtual build-dependencies make cmake g++ && \
    BUNDLE_FORCE_RUBY_PLATFORM=1 && \
    bundle check || bundle install --system --without=test development && \
    rm -rf /usr/local/bundle/cache/*.gem && \
    find /usr/local/bundle/gems/ -regex ".*\.[coh]" -delete && \
    apk del build-dependencies

FROM ruby:3.3.0-alpine
ENV INFO="Truemail lightweight rack based web API 🚀" \
    APP_USER="truemail" \
    APP_HOME="/var/lib/truemail-rack" \
    APP_PORT="9292"
LABEL description=$INFO
RUN apk add curl && \
    adduser -D $APP_USER
COPY --from=Builder /usr/local/bundle/ /usr/local/bundle/
COPY --from=Builder --chown=truemail:truemail $APP_HOME $APP_HOME
USER $APP_USER
WORKDIR $APP_HOME
EXPOSE $APP_PORT
CMD echo $INFO && thin -R config.ru -a 0.0.0.0 -p $APP_PORT -e production start
HEALTHCHECK --interval=5s --timeout=3s \
  CMD curl -f echo "http://localhost:${APP_PORT}/healthcheck" || exit 1