mkdir -p /opt/backup/app
# this is because we usually do repository backup to sibling directories in the tree
chown postgres:postgres /opt/backup
chown root:root /opt/backup/app
chmod 700 /opt/backup/app
# deploy the script above:
vim /opt/backup/backup_app.sh
chown root:root /opt/backup/backup_app.sh
chmod 750 /opt/backup/backup_app.sh