When running the open5gs package with systemd network config, the 1st IP address
of the UE pool configured in open5gs-upfd config file for ogstun is
being assigned to the interface through this file.
That was discussed as being a desirable default setup.
However, in the event a user wants a setup where no IP address is
assigned to the tundev, then it's not enough removing the IP address,
because then the implicit routing rules regarding the subnet of the IP
address added automatically by the kernel are also removed.
This patch adds config sections to set up the routing explicitly, with
the aim to get the routing still applied if the user decides to comment
out the IP address, so that packets are still forwarded properly in that
case.
Related: https://osmocom.org/issues/6361
* [configs] Do not require ogstun for system online
Systemd-networkd will wait for all managed interfaces to be configured
before determining the system is online. Since the ogstun and upf are
more logically an application rather than a system networking service,
don't wait for them to be configured by default.
This breaks the circular dependency between the userspace cellular
core network services and the system's network, which will allow the
cellular core network services to sequence themselves cleanly after
the system's network is up and configured.
* [configs] Sequence network-dependent units after network-online
Since open5gs targets platforms with both ifupdown (debian) and
systemd-networkd (Ubuntu) as core networking providers, this commit
sequences network-dependent core network components after the generic
network-online.target instead of one of the specific provider
targets. This allows the core network to operate correctly with both
systemd-networkd and ifupdown (networking), and fixes the issue
observed in https://github.com/open5gs/open5gs/issues/826 where some
platforms may fail to start cleanly.
Pau Espin
Sukchan Lee
Matthew Johnson
Julian Lemmerich
Spencer Sevilla