networking.service: fix start networking.service before network is marked online

[tjjh89017]

In debian 10, ifupdown2 didn't ensure that it will start before network.target and network-online.target.
after local-fs.target because ifupdown2 need to read config file from local filesystem
Other network services will not start after networking.service and fail because no interface is up.
(e.g isc-dhcp-server, tftp-hpa)

In Cumulus, this patch shouldn't be a problem because all switch ports need to be up before starting console for login.
and also need to read config file in local filesystem (need "After=local-fs.target")

[tjjh89017]

Hi @julienfortin
Could you please check this PR with Debian 10?
It will be a problem in debian system.
Thanks a lot

[tjjh89017]

Related to #30

[tjjh89017]

Related to dentproject/dentOS@1d553a9

[aderumier]

Hi,
see proxmox patch too:

https://git.proxmox.com/?p=ifupdown2.git;a=blob;f=debian/patches/pve/0007-networking.service-fix-dependencies-and-ordering.patch;h=66d1e18dfc303231d8e0dc9a81623eae7e541e37;hb=HEAD

we also have added a ifupdown2-pre.service, like ifupdown-pre.service on debian, to wait for systemd-udevd

[tjjh89017]

Hi,
see proxmox patch too:

https://git.proxmox.com/?p=ifupdown2.git;a=blob;f=debian/patches/pve/0007-networking.service-fix-dependencies-and-ordering.patch;h=66d1e18dfc303231d8e0dc9a81623eae7e541e37;hb=HEAD

we also have added a ifupdown2-pre.service, like ifupdown-pre.service on debian, to wait for systemd-udevd

It seems PVE will wait for all interface is created and named by udev.
Am I correct?

[aderumier]

@tjjh89017

yes, like debian, because some users using infiniband need it

Initialy debian had added a simple "after=systemd-udev-settle.service"

https://bugs.debian.org/cgi-bin/bugreport.cgi?att=1;bug=920623;filename=0001-Depend-on-systemd-udev-settle.service-in-networking..patch;msg=27

but some users with bad devices can have problem, so debian have done it in another ifupdown-pre.service, so user can mask it if it don't want to wait.

proxmox have done the same with ifupdown2-pre.service

[tjjh89017]

It seems we should follow ifupdown-pre way to make sure

[julienfortin]

@aderumier should I merge this? I don't want anything to break for anybody.
I honestly don't know much about systemd and dependencies. Dave was our systemd guy but he retired a few years ago 😅

I just tried it on Cumulus Linux 4.4, everything seems OK for us.

I also read the proxmox downstream patch, feel free to submit another PR (if you'd like more changes) as long as those changes work for every debian/ubuntu without breaking existing setups.

[aderumier]

@julienfortin

About systemd ordering and depend, I think you could ask to proxmox team, as I'm not a big expert with systemd too ;)

This proxmox dev could help
https://github.com/blub
Wolfgang Bumiller w.bumiller@proxmox.com

I known he have tried to push to pull request about it some year ago, and they was closed.

See this commit:

https://git.proxmox.com/?p=ifupdown2.git;a=blob;f=debian/patches/pve/0007-networking.service-fix-dependencies-and-ordering.patch;h=66d1e18dfc303231d8e0dc9a81623eae7e541e37;hb=HEAD

#68
(I don't remember why it was refused at this time)

Also, in proxmox , for udevadm-settle, we have implement an ifupdown2-pre.service , to have same behaviour than debian classic ifupdown1 with ifupdown-service.
I can be usefull, as some user with buggy hardware, can have a hang with udevadm-settle, so they just need to mask the ifupdown2-pre.service to bypass it.

[tjjh89017]

I'm sure we will need Before=network.target network-online.target to ensure any service depends on network should wait for ifupdown2.
but I'm not sure we need ifupdown2-pre.service in upstream or leave it in distro pkgs patch?