Put this into /etc/init/web2py-scheduler.conf:

description "web2py task scheduler"

start on (local-filesystems and net-device-up IFACE=eth0)
stop  on shutdown

# Give up if restart occurs 8 times in 60 seconds.                              
respawn limit 8 60

exec sudo -u <user> python /home/<user>/web2py/web2py.py -K <appname>
respawn

This assumes your web2py is installed in <user>'s home directory and runs under <user>'s account.

Replace eth0 if you use a different network interface on the server.

Your scheduler will launch automatically when you reboot your machine, or you can start/stop/restart/check the status of it manually with:

sudo start web2py-scheduler
sudo stop web2py-scheduler
sudo restart web2py-scheduler
sudo status web2py-scheduler

...etc.