Docker container for geoserver
JAVA_OPTS (default: -Xms128m -Xmx512m -XX:MaxPermSize=512m)
ADMIN_PASSWD (default: geoserver)
8080: REST and Admin interface
/opt/geoserver/data_dir: default application data directory
/opt/geoserver/data_dir/styles: styles (sld, xml, images) directory
Source: Taken from neowaylabs/geoserver