Improved Docker build and docker images (#1488)

* Using upacked Spring layers for faster boot
* Added option to pass JAVA_OPT to modify the environment variables in both flavours
* Build support for different hawkbit apps - could be used in future if hawkBit is split in multiple micro-services
* Removed templates and replacing with parameterized (via build ARGs) docker builds

Signed-off-by: Marinov Avgustin <Avgustin.Marinov@bosch.com>

hawkbit-runtime/docker/dockerfiles/Dockerfile

@@ -0,0 +1,42 @@
+# set Java
+ARG JAVA_VERSION=17.0.9_9
+# extracts spring layers from the app jar (to optimize boot)
+FROM eclipse-temurin:${JAVA_VERSION}-jre-alpine as build
+
+ARG HAWKBIT_APP=hawkbit-update-server
+ARG HAWKBIT_VERSION=0.3.0
+
+ENV BUILD_DIR=/opt/hawkbit_build
+ENV APP=${HAWKBIT_APP}
+ENV VERSION=${HAWKBIT_VERSION}
+
+COPY KEY .
+
+RUN set -x &&\
+ apk add --no-cache --virtual build-dependencies gnupg unzip libressl wget &&\
+ gpg --import KEY &&\
+ mkdir -p ${BUILD_DIR} &&\
+ cd ${BUILD_DIR} &&\
+ wget -O ${APP}.jar --no-verbose https://repo1.maven.org/maven2/org/eclipse/hawkbit/${APP}/${VERSION}/${APP}-${VERSION}.jar &&\
+ wget -O ${APP}.jar.asc --no-verbose https://repo1.maven.org/maven2/org/eclipse/hawkbit/${APP}/${VERSION}/${APP}-${VERSION}.jar.asc &&\
+ gpg --batch --verify ${APP}.jar.asc ${APP}.jar &&\
+ apk del build-dependencies &&\
+ java -Djarmode=layertools -jar ${APP}.jar extract --destination . &&\
+ rm ${APP}.jar ${APP}.jar.asc /KEY
+
+FROM eclipse-temurin:${JAVA_VERSION}-jre-alpine
+
+RUN addgroup -S rollouts && adduser -D sp -G rollouts
+USER sp
+
+ENV BUILD_DIR=/opt/hawkbit_build
+COPY --from=build ${BUILD_DIR}/dependencies/ ./
+COPY --from=build ${BUILD_DIR}/spring-boot-loader/ ./
+COPY --from=build ${BUILD_DIR}/snapshot-dependencies/ ./
+COPY --from=build ${BUILD_DIR}/application/ ./
+
+ARG CONTAINER_PORT=8080
+ENV JAVA_OPTS="-Xms768m -Xmx768m -XX:MaxMetaspaceSize=250m -XX:MetaspaceSize=250m -Xss300K -XX:+UseG1GC -XX:+UseStringDeduplication -XX:+UseCompressedOops -XX:+HeapDumpOnOutOfMemoryError"
+
+EXPOSE ${CONTAINER_PORT}
+ENTRYPOINT ["sh", "-c", "java ${JAVA_OPTS} org.springframework.boot.loader.JarLauncher ${@}"]