Add PORT and CONTEXT_PATH env variables

Dockerfile

@@ -2,6 +2,8 @@ FROM java:8
 MAINTAINER Cyrille Nofficial<cynoffic@cyrilix.fr>
 
 ENV SUBSONIC_VERSION 5.2.1
+ENV PORT 8080
+ENV CONTEXT_PATH /
 
 LABEL version="$SUBSONIC_VERSION"
 LABEL description="Subsonic media streamer"
@@ -13,18 +15,16 @@ RUN     mkdir -p /opt/subsonic  /opt/data /opt/music/ &&\
 VOLUME /opt/data
 VOLUME /opt/music/
 
-EXPOSE 8080
+EXPOSE $PORT
 WORKDIR /opt/subsonic
 
 CMD java -Xmx100m \
             -Dsubsonic.home=/opt/data \
-            -Dsubsonic.port=8080 \
-            -Dsubsonic.contextPath=/ \
+            -Dsubsonic.port=$PORT \
+            -Dsubsonic.contextPath=$CONTEXT_PATH \
             -Dsubsonic.defaultMusicFolder=/opt/music/ \
             -Dsubsonic.defaultPodcastFolder=/opt/music/ \
             -Dsubsonic.defaultPlaylistFolder=/opt/music/ \
             -Djava.awt.headless=true \
             -verbose:gc \
             -jar /opt/subsonic/subsonic-booter-jar-with-dependencies.jar
-
-

README.md

@@ -17,11 +17,11 @@ $ docker build -t <your-name>/docker-subsonic .
 A current image is available as a trusted build from the Docker index:
 
 ```shell
-$ docker pull  cyrilix/docker-subsonic
+$ docker pull  cyrilix/subsonic
 ```
 
 The repository page is at
-https://index.docker.io/u/cyrilix/docker-subsonic/
+https://index.docker.io/u/cyrilix/subsonic/
 
 
 ## Run a container with this image
@@ -34,3 +34,11 @@ $ docker run \
   <your-name>/subsonic
 
 ```
+
+## Configuration
+
+Specify env variables:
+
+  * CONTEXT_PATH =  The context path, i.e., the last part of the Subsonic URL. Typically '/' or '/subsonic'. Default '/'
+  * PORT = The port on which Subsonic will listen for incoming HTTP traffic. Default: 8080
+