units: networkd - don't order wait-online.service before network.target Reported by Michael Olbrich.

units: order network-online.target after network.target There might be implementations around where the network-online logic might not talk to any network configuration service (and thus not have to wait for it), hence let's explicitly order network-online.target after network.target to avoid any ambiguities.

networkd-wait-online: improve interoptability and enable by default To make sure we don't delay boot on systems where (some) network links are managed by someone else we don't block if something else has successfully brought up a link. We will still block until all links we are aware of that are managed by networkd have been configured, but if no such links exist, and someone else have configured a link sufficiently that it has a carrier, it may be that the link is ready so we should no longer block. Note that in all likelyhood the link is not ready (no addresses/routes configured), so whatever network managment daemon configured it should provide a similar wait-online service to block network-online.target until it is ready. The aim is to block as long as we know networking is not fully configured, but no longer. This will allow systemd-networkd-wait-online.service to be enabled on any system, even if we don't know whether networkd is the main/only network manager. Even in the case networking is fully configured by networkd, the default behavior may not be sufficient: if two links need to be configured, but the first is fully configured before the second one appears we will assume the network is up. To work around that, we allow specifying specific devices to wait for before considering the network up. This unit is enabled by default, just like systemd-networkd, but will only be pulled in if anyone pulls in network-online.target.