Fix Dockerfile issues (#233)

Dockerfile

@@ -1,29 +1,38 @@
-ARG BASE_IMAGE=ruby:3.4-alpine
+ARG RUBY_VERSION=3.4.1
 ARG APP_ROOT=/app
 
-FROM $BASE_IMAGE AS build-env
+# base
+FROM docker.io/library/ruby:$RUBY_VERSION-alpine AS base
 ARG APP_ROOT
-WORKDIR $APP_ROOT
+WORKDIR "$APP_ROOT"
 RUN apk update && apk upgrade && \
     apk add build-base && \
     rm -rf /var/cache/apk/*
-COPY Gemfile* ./
-RUN bundle install --without=development test
+ENV BUNDLE_DEPLOYMENT="1"
+ENV BUNDLE_PATH="/usr/local/bundle"
+ENV BUNDLE_WITHOUT="development"
 
-FROM $BASE_IMAGE AS final
+# build
+FROM base AS build
+RUN apk update && apk upgrade && \
+    apk add build-base && \
+    rm -rf /var/cache/apk/*
+COPY Gemfile Gemfile.lock ./
+RUN bundle install && \
+    rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git
+
+# final
+FROM base
 ARG APP_ROOT
-ARG BUILD_DATE
-ARG SOURCE
-ARG REVISION
-ARG BUNDLE_DIR=/usr/local/bundle
-LABEL org.opencontainers.image.licenses="MIT"
-LABEL org.opencontainers.image.title="SamlProxy"
-LABEL org.opencontainers.image.created="$BUILD_DATE"
-LABEL org.opencontainers.image.source="$SOURCE"
-LABEL org.opencontainers.image.revision="$REVISION"
-WORKDIR $APP_ROOT
-COPY --from=build-env $BUNDLE_DIR $BUNDLE_DIR
-COPY . .
+COPY --from=build "${BUNDLE_PATH}" "${BUNDLE_PATH}"
+COPY --from=build "${APP_ROOT}" "${APP_ROOT}"
+COPY helpers ./helpers
+COPY config ./config
+COPY config.ru saml_proxy.rb LICENSE "$APP_ROOT"
+RUN addgroup --system --gid 1000 samlproxy && \
+    adduser --system --uid 1000 samlproxy --ingroup samlproxy && \
+    chown -R samlproxy:samlproxy "$APP_ROOT"
+USER samlproxy
 ENV RACK_ENV=production
 ENV PORT=9292
 CMD ["bundle", "exec", "puma"]