use geonetwork.dir environment variable over custom data_dir

[pvgenuchten]

Current image has a docker-only param DATA_DIR which sets geonetwork.dir as a java environment parameter in a deploy script

docker-geonetwork/3.10.0/docker-entrypoint.sh

Line 9 in 9fcf085

export CATALINA_OPTS="$CATALINA_OPTS -Dgeonetwork.dir=$DATA_DIR"

In stead would be better to use the mechanism available in geonetwork to set the data directory with environment variable by using

docker run -e genoetwork.dir=/mnt/gn

Java environment variable takes preference over system environment variable, so you can not override data_dir by geonetwork.dir (data_dir takes default value if not set)