Event signalling system startup
The startup event is generated by the Upstart init(8) daemon after it has completed its own initialisation and is the signal that the rest of the system may be started.
Typically this will involve checking and mounting the partitions and drives that form the filesystem, loading drivers for connected devices and starting the X windowing system or other login environment.
In the default Upstart configuration, the primary task run on the startup event is the /etc/init/rc-sysinit.conf job responsible for generating the System V compatible runlevel(7) event. See that page for a more detailed explanation of this process.
This event is emitted when running both as pid 1 and as a Session Init.
Paradoxically there is currently no corresponding Upstart-native event signifying that the system is to be shutdown, only the System V compatible runlevel 0 and runlevel 6 events provide this functionality. However, when running as a Session Init, the session-end event performs this function.
A service with no other dependencies run on startup might use:
start on startup