encfs always runs a configuration assistant when creating a new
volume, so this needs to be done manually:
systemctl stop postgresql@12-main
mv /var/lib/postgresql /var/lib/postgresql.old
encfs /var/lib/postgresql_encrypted /var/lib/postgresql --public
Pick p (paranoia mode) and enter the password from the data bag twice
mv /var/lib/postgresql/* /var/lib/postgresql/
systemctl start postgresql@12-main
This is running on centaurus and is mounted automatically on boot by a
system unit
Refs #129