Ubuntu – Will Ubuntu 18.04 LTS still support Upstart or do we have to change to systemd

If you want to, you can instead make a systemd .service file that does the same thing. A basic systemd .service file for the above command might look like the following:

[Unit]
Description=Start VNC server
Requires=lightdm.service
After=lightdm.service

[Service]
ExecStart=/usr/bin/x11vnc -auth /var/run/lightdm/root/:0  -display :0  -rfbauth /etc/x11vnc.pass  -rfbport 5900  -noxrecord -noxfixes -noxdamage -forever

[Install]
WantedBy=graphical.target

Things to note:

• Because this service relies on lightdm starting up, I've added a Requires=lightdm.service. This means that if this service is requested to start, then lightdm.service will also be asked to start, but if lightdm.service fails to start, then this service won't be asked to start. Additionally, After=lightdm.service is needed so that this service will start after `lightdm.service has finished starting.
• The command being run doesn't have -bg specified. In systemd, it's preferred that services stay in the foreground, so that systemd knows that they are running. Note that it is possible to specify a PID file for a service that goes into the background.
• WantedBy=graphical.target specifies that, as part of starting up your GUI, this should also get started up.

To install this file so that the service is run as root, add this file into /etc/systemd/system. Then, run sudo systemctl enable <filename> (where <filename> is the name of the service file in /etc/systemd/system). A symlink should be created in /etc/systemd/system/graphical.target.wants/. After rebooting, when you run systemctl status <filename>, you should see that the service is recognized and not yet started.

Note that /etc/systemd/system/ is meant for system-wide services that the system administrator (you) add. /lib/systemd/system/ is meant for system-wide services installed by packages. You do not need to make a symlink to /lib/systemd/system/ for the service to load. The below table (taken from the systemd.unit manpage) describes what each location is for with regards to system services (there are separate paths for user services):

   ┌────────────────────┬─────────────────────────────┐
   │Path                │ Description                 │
   ├────────────────────┼─────────────────────────────┤
   │/etc/systemd/system │ Local configuration         │
   ├────────────────────┼─────────────────────────────┤
   │/run/systemd/system │ Runtime units               │
   ├────────────────────┼─────────────────────────────┤
   │/lib/systemd/system │ Units of installed packages │
   └────────────────────┴─────────────────────────────┘

Unlikely anyone will be able to answer this based on facts but I would assume that ...

• switching from GRUB like you can do now (at run time) is likely to disappear and this is also likely to happen when 16.04 LTS arrives. During the Ubuntu Developer Summit (UDS 14.03) Mark Shuttleworth announced that systemd will be used as default on the next LTS version of Ubuntu, Ubuntu 16.04.

• but as long as the package is available you can install it yourself. 15.10 still has upstart. How well new services will be supported by upstart is anyone's guess. Even I myself doubt it will be supported.

So I assume the answer is yes but with increasingly difficulty. I would forget about upstart and get to know systemd. In this case I would advice to not swim against the current.