guisea

To backup:
docker exec -u <your_postgres_user> <postgres_container_name> pg_dump -Fc <database_name_here> > db.dump

To drop db (Don't do it on production, for test purpose only!!!):
docker exec -u <your_postgres_user> <postgres_container_name> psql -c 'DROP DATABASE <your_db_name>'

To restore:
docker exec -i -u <your_postgres_user> <postgres_container_name> pg_restore -C -d postgres < db.dump

working example for awx postgres database