feat(maven) add JDK11 to the JDK17 (#33)

Signed-off-by: Damien Duportal <damien.duportal@gmail.com>

maven/jdk17/Dockerfile

@@ -1,4 +1,17 @@
-# Use Debian base
+ARG JAVA_VERSION="11.0.16_8"
+FROM eclipse-temurin:${JAVA_VERSION}-jdk-focal AS jdk11-build
+# Generate smaller java runtime without unneeded files
+# for now we include the full module path to maintain compatibility
+# while still saving space (approx 200mb from the full distribution)
+RUN jlink \
+    --add-modules ALL-MODULE-PATH \
+    --strip-debug \
+    --no-man-pages \
+    --no-header-files \
+    --compress=2 \
+    --output /javaruntime
+
+# Use Debian base for both the agent and the resulting image (maven)
 FROM jenkins/inbound-agent:jdk17-preview as jnlp
 
 FROM maven:3.8.6-eclipse-temurin-17
@@ -17,6 +30,9 @@ RUN apt-get update && \
 COPY --from=jnlp /usr/local/bin/jenkins-agent /usr/local/bin/jenkins-agent
 COPY --from=jnlp /usr/share/jenkins/agent.jar /usr/share/jenkins/agent.jar
 
+# Retrieve JDK11 for running jenkins agent process but do not use it as default
+COPY --from=jdk11-build /javaruntime /opt/jdk-11
+
 ENTRYPOINT ["/usr/local/bin/jenkins-agent"]
 
 ARG user=jenkins