Hi,
docker image by default starts with the default database, in memory.
You should connect MapStore to a postgres DB,
e.g.
docker run \
-v `pwd`/docker/geostore-datasource-ovr-postgres.properties:/usr/local/tomcat/conf/geostore-datasource-ovr.properties \
-e JAVA_OPTS="-Xms512m -Xmx512m -XX:MaxPermSize=128m -Dgeostore-ovr=file:///usr/local/tomcat/conf/geostore-datasource-ovr.properties" \
--name mapstore \
-p8080:8080 \
geosolutionsit/mapstore2
For database setup, look
here.