If you'd still like to continue using /etc/rc.d/rc.local, and it would
be
enough for it to be executed "after boot", IOW, after the default
runlevel at boot is reached, the following four commands might help
you:
$ cat >/tmp/order-last.conf <<EOConf
[Unit]
After=default.target
[Service]
StandardOutput=journal+console
StandardError=journal+console
EOConf
$ mkdir -p /etc/systemd/system/rc-local.service.d/
$ mv /tmp/order-last.conf /etc/systemd/system/rc-local.service.d/
$ systemctl daemon-reload
Then, make sure `rc-local.service` is enabled.
default.target should be a symlink to another target, likely multi-user
or graphical.
Isn't that the same as running "systemctl edit rc-local.service" and
then enter that config there?
Best regards,
Aki