Merge pull request #7 from PlusMinus0/root_fix

Root fix

README.md

@@ -2,11 +2,39 @@
 Headless JDownloader 2 Docker Container
 
 ## Running the container
-0. `sudo su`
-1. Create a folder on your host for the configuration files (eg. sudo mkdir /config/jd2)
-2. run `docker run -d --name jd2 -v /config/jd2:/opt/JDownloader/cfg -v /home/user/Downloads:/root/Downloads plusminus/jdownloader2-headless`
-3. stop the container `docker stop jd2`
-4. On your host, enter your credentials (in quotes) to the file `org.jdownloader.api.myjdownloader.MyJDownloaderSettings.json` as in `{ "password" : "mypasswort", "email" : "email@home.org" }`
-5. Start the container
+0.  Become root if your user is not part of the docker group:
 
+    ```
+    sudo su
+    ```
+1.  Create a folder on your host for the configuration files (eg. sudo mkdir /config/jd2)
+2.  Run the container:
 
+    ```
+    docker run -d --name jd2 \
+        -v /config/jd2:/opt/JDownloader/cfg \
+        -v /home/user/Downloads:/downloads \
+        plusminus/jdownloader2-headless
+    ```
+3.  Wait a minute for the container to initialize
+4.  Stop the container:
+
+    ```
+    docker stop jd2
+    ```
+5.  On your host, enter your credentials (in quotes) to the file `org.jdownloader.api.myjdownloader.MyJDownloaderSettings.json` as in:
+
+    ```
+    { "password" : "mypasswort", "email" : "email@home.org" }
+    ```
+6.  Start the container:
+
+    ```
+    docker start jd2
+    ```
+    
+## Optional environment variables
+|Environment Variable|Description|
+|--------------------|-----------|
+|UID|Specifies the UID the daemon should run as. All created files will be owned by this UID. Defaults to 0 for root.|
+|GID|Specifies the GID for all created files. This only works in combination with the UID. Defaults to 0 for root.|

startJD2.sh

@@ -7,9 +7,28 @@ function stopJD2 {
 	exit
 }
 
+if [ "$GID" ]
+then
+	GROUP=jdownloader
+	groupadd -g $GID $GROUP
+else
+	GROUP=root
+fi
+
+if [ "$UID" ] 
+then
+	USER=jdownloader
+	useradd -r -s /bin/false -u $UID $USER
+else
+	USER=root
+fi
+
+useradd -G $GROUP $USER
+chown -R $USER:$GROUP /opt/JDownloader
+
 trap stopJD2 EXIT
 
-java -Djava.awt.headless=true -jar /opt/JDownloader/JDownloader.jar &
+su -c "java -Djava.awt.headless=true -jar /opt/JDownloader/JDownloader.jar &" -s /bin/bash $USER
 
 while true; do
 	sleep inf