Docker image usability

Dockerfile

@@ -101,7 +101,9 @@ RUN addgroup -S gerbera 2>/dev/null && \
     adduser -S -D -H -h /var/run/gerbera -s /sbin/nologin -G gerbera -g gerbera gerbera 2>/dev/null && \
     addgroup gerbera video && \
     mkdir /var/run/gerbera/ && chmod 2775 /var/run/gerbera/ && \
-    mkdir /content && chmod 777 /content
+    mkdir /content && chmod 777 /content && ln -s /content /mnt/content && \
+    mkdir -p /mnt/customization/js && mkdir -p /mnt/customization/shell && \
+    chmod -R 777 /mnt/customization
 
 EXPOSE 49494
 EXPOSE 1900/udp

README.Docker.md

@@ -35,7 +35,7 @@ e.g. `gerbera/gerbera:1.9.2-transcoding`. Includes tools such as ffmpeg and vlc.
 $ docker run \
     --name some-gerbera \
     --network=host \
-    -v /some/files:/content:ro \
+    -v /some/files:/mnt/content:ro \
      gerbera/gerbera:vX.X.X
 ```
 
@@ -51,22 +51,26 @@ services:
     network_mode: host
     volumes:
       - gerbera-config:/var/run/gerbera
-      - /some/files:/content:ro
+      - /some/files:/mnt/content:ro
 
 volumes:
   gerbera-config:
     external: false
 ```
 
-The directory `/content` is automatically scanned for content by default.
+The directory `/mnt/content` is automatically scanned for content by default.
 Host networking enables us to bypass issues with broadcast across docker bridges.
 
+You may place custom JavaScript files in the directory `/mnt/customization/js`.
+Every time Gerbera creates `/var/run/gerbera/config.xml`, the shell script
+`/mnt/customization/shell/gerbera_config.sh` (if existing) will be executed.
+
 ## Provide your own config file
 ```console
 $ docker run \
     --name another-gerbera \
     --network=host \
-    -v /some/files:/content:ro \
+    -v /some/files:/mnt/content:ro \
     -v /some/path/config.xml:/var/run/gerbera/config.xml \
      gerbera/gerbera:vX.X.X
 ```

scripts/docker/docker-entrypoint.sh

@@ -34,6 +34,15 @@ if [ ! -f /var/run/gerbera/config.xml ]; then
     <directory location="\/content" mode="inotify" \
     recursive="yes" hidden-files="no"\/>\n\
     <\/autoscan>/' -i /var/run/gerbera/config.xml
+
+  # Add directory for custom JavaScript scripts
+  sed 's/<\/common>/<\/common>\
+        <custom>\/mnt\/customization\/js<\/custom>/' -i /var/run/gerbera/config.xml
+
+  # Allow customization of Gerbera configuration file
+  if [ -x /mnt/customization/shell/gerbera_config.sh ]; then
+    . /mnt/customization/shell/gerbera_config.sh
+  fi
 fi
 
 if [ -e /dev/video10 ]; then