Add template for java docker images

Dockerfile.customJRE

@@ -0,0 +1,41 @@
+FROM alpine:3.17 as BUILD
+RUN apk add --no-cache binutils maven openjdk17-jdk
+WORKDIR /build
+COPY pom.xml .
+RUN mvn dependency:go-offline
+COPY src/ /build/src/
+RUN export BUILD_DIRECTORY="$(mvn help:evaluate -Dexpression='project.build.directory' -q -DforceStdout)" && \
+    export BUILD_NAME="$(mvn help:evaluate -Dexpression='project.build.finalName' -q -DforceStdout)" && \
+    mvn package && \
+    mkdir unpacked && \
+    cd unpacked && \
+    unzip /build/target/${BUILD_NAME}.jar && \
+    cd .. && \
+    mkdir -p /build/unpacked/BOOT-INF/lib && \
+    cp ${BUILD_DIRECTORY}/${BUILD_NAME}.lib/*.jar /build/unpacked/BOOT-INF/lib/ && \
+    jdeps \
+        --ignore-missing-deps \
+        --print-module-deps \
+        -q \
+        --recursive \
+        --multi-release 17 \
+        --class-path="./unpacked/BOOT-INF/lib/*" \
+        --module-path="./unpacked/BOOT-INF/lib/*" \
+        ${BUILD_DIRECTORY}/${BUILD_NAME}.jar > ${BUILD_DIRECTORY}/deps.info && \
+    jlink \
+        --verbose \
+        --add-modules $(cat ${BUILD_DIRECTORY}/deps.info) \
+        --strip-debug \
+        --no-man-pages \
+        --no-header-files \
+        --compress=2 \
+        --output ./jre && \
+    echo -e "#!/bin/sh\n" \
+        "/opt/jre/bin/java -jar ${BUILD_NAME}.jar" \
+        > ${BUILD_DIRECTORY}/run.sh && \
+    chmod 700 ${BUILD_DIRECTORY}/run.sh
+FROM alpine:3.17
+COPY --from=BUILD /build/target/ /opt/target/
+COPY --from=BUILD /build/jre /opt/jre
+WORKDIR /opt/target
+ENTRYPOINT ["./run.sh"]

README.md

@@ -6,3 +6,4 @@ All compose files assume that the containers are run behind a reverse proxy, tha
 * **gitea** - Git repository server
 * **thea** - Online IDE
 * **wallabag** - Read later app
+* **Dockerfile.customJRE** - Create a image from a maven java project with custom JRE