[systemd-devel] network consuming user services

[David Strauss]

On Wed, May 2, 2012 at 3:58 PM, Lennart Poettering
<lennart at poettering.net> wrote:
> But if you want that you can do that simply by enabling NetworkManager-wait-online.service, which then delays
> network.target accordingly.

That would work, but it has potential undesirable effects:

* Any services associated with network.target will wait longer to
start, even if all they need to do is bind to *:80. This reduces
parallelism.
* If NetworkManager-wait-online.service causes network.target to only
fire once all interfaces are up, a service like openssh-server might
not start if only one of the interfaces comes up. This occasionally
happens on multihomed systems where only the public or private
interface comes up. It would be annoying to not have SSH access in
such a situation.
* It's not clear when or how network.target gets "stopped." If
network.target stops on loss of any interface, existing services might
flap unnecessarily. It would be bad to have MySQL, for example, stop
or restart because a switch restarted. If network.target never gets
stopped or only gets stopped on total network shutdown (no 127.0.0.1),
it would not solve Sebastian's use case. His use case requires
stopping certain network-dependent services when links go down.