Systemd service life cycle

[Ralf Mardorf]

On Sat, 9 Apr 2016 22:06:43 +0100, Colin Law wrote:
>On 9 April 2016 at 21:59, Tom H wrote:
>> It's for a unit that doesn't have any active processes after
>> ExecStart runs. I've used it for setting up networking and
>> firewalling, for example.  
>
>Is not the tunnel an 'active process' though?

Systemd considers the oneshot service as active after a process
exited, if you use RemainAfterExit=true or RemainAfterExit=yes.

A script might execute "ip link set * up; pon" or "dhcpcd *" and
then exits. After the script exited PPPoE or DHCP are quasi active, OTOH
a connection not necessarily is already established after a script
exited with status 0.