Build with bookworm

Use custom JRE at runtime, not full JDK

Dockerfile

@@ -1,24 +1,58 @@
-FROM docker.io/maven:3-eclipse-temurin-17
+###########
+#
+# Build with:
+# podman build -tsnmpman .
+#
+# Run with:
+# podman run -p127.0.0.1:10000:10000/udp snmpman 
+#
+###########
+
+#
+# maven build
+#
+FROM docker.io/maven:3-eclipse-temurin-17 as maven-build
 COPY . /snmpman
 RUN cd /snmpman && mvn clean package
 
-FROM docker.io/debian:bookworm
+#
+# create JRE
+#
+FROM docker.io/debian:bookworm as jre-build
 ARG JAVA_VERSION=17
 ENV JAVA_HOME=/opt/java/openjdk
 COPY --from=docker.io/eclipse-temurin:${JAVA_VERSION} /opt/java/openjdk $JAVA_HOME
 ENV PATH="${JAVA_HOME}/bin:${PATH}"
 
+RUN apt-get update && apt-get install --yes binutils
+# Create a custom Java runtime
+RUN $JAVA_HOME/bin/jlink \
+         --add-modules java.base,java.xml,java.desktop,java.management,java.naming \
+         --strip-debug \
+         --no-man-pages \
+         --no-header-files \
+         --compress=2 \
+         --output /javaruntime
+
+#
+# combine JRE + JAR
+#
+FROM docker.io/debian:bookworm
+ENV JAVA_HOME=/opt/java/openjdk
+COPY --from=jre-build /javaruntime $JAVA_HOME
+ENV PATH="${JAVA_HOME}/bin:${PATH}"
+
 #RUN apt-get update && apt-get install --yes snmp tcpdump strace iproute2 net-tools
 RUN useradd snmpman
-COPY --chown=snmpman:snmpman --from=0 /snmpman/snmpman-cli/target/snmpman-cli-*bin /snmpman
-COPY --chown=snmpman:snmpman --from=0 /snmpman/snmpman-cli/src/main/config/devices/catos.yaml /snmpman/etc/devices/
-COPY --chown=snmpman:snmpman --from=0 /snmpman/snmpman-cli/src/main/config/devices/finesse.yaml /snmpman/etc/devices/
-COPY --chown=snmpman:snmpman --from=0 /snmpman/snmpman-cli/src/main/config/devices/foundry.yaml /snmpman/etc/devices/
-COPY --chown=snmpman:snmpman --from=0 /snmpman/snmpman-cli/src/main/config/devices/iosxr.yaml /snmpman/etc/devices/
-COPY --chown=snmpman:snmpman --from=0 /snmpman/snmpman-cli/src/main/config/devices/ios.yaml /snmpman/etc/devices/
-COPY --chown=snmpman:snmpman --from=0 /snmpman/snmpman-cli/src/main/config/devices/junos.yaml /snmpman/etc/devices/
-COPY --chown=snmpman:snmpman --from=0 /snmpman/snmpman-cli/src/main/config/devices/nxos.yaml /snmpman/etc/devices/
-COPY --chown=snmpman:snmpman --from=0 /snmpman/snmpman-cli/src/main/config/walk/example1.walk /snmpman/etc/walk/
+COPY --chown=snmpman:snmpman --from=maven-build /snmpman/snmpman-cli/target/snmpman-cli-*bin /snmpman
+COPY --chown=snmpman:snmpman --from=maven-build /snmpman/snmpman-cli/src/main/config/devices/catos.yaml /snmpman/etc/devices/
+COPY --chown=snmpman:snmpman --from=maven-build /snmpman/snmpman-cli/src/main/config/devices/finesse.yaml /snmpman/etc/devices/
+COPY --chown=snmpman:snmpman --from=maven-build /snmpman/snmpman-cli/src/main/config/devices/foundry.yaml /snmpman/etc/devices/
+COPY --chown=snmpman:snmpman --from=maven-build /snmpman/snmpman-cli/src/main/config/devices/iosxr.yaml /snmpman/etc/devices/
+COPY --chown=snmpman:snmpman --from=maven-build /snmpman/snmpman-cli/src/main/config/devices/ios.yaml /snmpman/etc/devices/
+COPY --chown=snmpman:snmpman --from=maven-build /snmpman/snmpman-cli/src/main/config/devices/junos.yaml /snmpman/etc/devices/
+COPY --chown=snmpman:snmpman --from=maven-build /snmpman/snmpman-cli/src/main/config/devices/nxos.yaml /snmpman/etc/devices/
+COPY --chown=snmpman:snmpman --from=maven-build /snmpman/snmpman-cli/src/main/config/walk/example1.walk /snmpman/etc/walk/
 COPY docker/docker-entrypoint.sh /docker-entrypoint.sh
 USER snmpman
 EXPOSE 10000/udp