adjust to upstream codebase

Dockerfile

@@ -1,9 +1,9 @@
-FROM openjdk:8-jre
+FROM openjdk:8-jre-alpine
 
 MAINTAINER PlusMinus <piddlpiddl@gmail.com>
 
 
-# Create directory, downloader JD" and start JD2 for the initial update and creation of config files.
+# Create directory, and start JD2 for the initial update and creation of config files.
 RUN \
 	mkdir -p /opt/JDownloader/ && \
 	wget -O /opt/JDownloader/JDownloader.jar --user-agent="https://hub.docker.com/r/plusminus/jdownloader2-headless/" --progress=bar:force http://installer.jdownloader.org/JDownloader.jar && \
@@ -14,5 +14,6 @@ COPY startJD2.sh /opt/JDownloader/
 RUN chmod +x /opt/JDownloader/startJD2.sh
 
 
+ENTRYPOINT ["/sbin/tini", "-g", "--", "/opt/JDownloader/startJD2.sh"]
 # Run this when the container is started
-CMD /opt/JDownloader/startJD2.sh
+CMD ["java", "-Djava.awt.headless=true", "-jar", "/opt/JDownloader/JDownloader.jar"]

startJD2.sh

@@ -1,12 +1,5 @@
 #!/bin/bash
 
-function stopJD2 {
-	PID=$(cat JDownloader.pid)
-	kill $PID
-	wait $PID
-	exit
-}
-
 if [ "$GID" ] && [ "$GID" -ne "0" ]
 then
 	GROUP=jdownloader
@@ -26,11 +19,5 @@ fi
 useradd -G $GROUP $USER
 chown -R $USER:$GROUP /opt/JDownloader
 
-trap stopJD2 EXIT
-
-su -c "java -Djava.awt.headless=true -jar /opt/JDownloader/JDownloader.jar &" -s /bin/bash $USER
-
-while true; do
-	sleep inf
-done
+exec su-exec "$@"