# 6. A custom runtime: jdeps works out which JDK modules the application needs, jlink builds a
#    JRE containing only those, and it goes onto distroless java-base (glibc, no JRE of its own).
#    See docs/05-jlink.md for the module list this produced and the one it initially missed.
FROM eclipse-temurin:25-jdk AS builder
WORKDIR /builder
COPY target/app.jar application.jar
RUN java -Djarmode=tools -jar application.jar extract --layers --destination extracted
# jdeps cannot see modules loaded reflectively. jdk.management is the one this application
# needs: without it Micrometer silently drops 15 metrics, GC pauses and CPU usage among them.
ARG EXTRA_MODULES="jdk.management"
RUN MODULES="$(jdeps --ignore-missing-deps -q --recursive --multi-release 25 --print-module-deps \
        --class-path 'extracted/dependencies/lib/*' extracted/application/application.jar)" \
 && MODULES="${MODULES}${EXTRA_MODULES:+,$EXTRA_MODULES}" \
 && echo "jlink modules: $MODULES" | tee /builder/modules.txt \
 && jlink --add-modules "$MODULES" --strip-debug --no-man-pages --no-header-files \
          --compress=zip-6 --output /builder/jre

FROM gcr.io/distroless/java-base-debian13:nonroot
COPY --from=builder /builder/jre /opt/jre
COPY --from=builder /builder/modules.txt /opt/jre/modules.txt
WORKDIR /application
COPY --from=builder /builder/extracted/dependencies/ ./
COPY --from=builder /builder/extracted/spring-boot-loader/ ./
COPY --from=builder /builder/extracted/snapshot-dependencies/ ./
COPY --from=builder /builder/extracted/application/ ./
ENTRYPOINT ["/opt/jre/bin/java", "-jar", "application.jar"]