Something isn't working here. I also typo'd the test-case, in particular, the change to the cloud-init.service unit didn't specify 'systemd-networkd-wait-online.service', the sed command missed the 'd' in networkd.
When I fix that, I find that systemd-networkd-resolvconf-update.service does NOT run. Manually adding that to /lib/systemd/system/resolvconf.service.wants fixes the networkd boot path, but of course breaks the ifupdown path. ** Description changed: Currently resolvconf and systemd-networkd don't ensure DNS has been configured before allowing network-online.target to be reached. This was discussed in https://launchpad.net/bugs/1636912 however it was not a regression since there aren't any users of networkd + DNS early in boot at this time, it was requested that we move this DNS issue to a separate bug. - [SRU] Fix: switch resolvconf.service to run Before=network-pre.target and add Wants=network-pre.target. Add a Before=network-online.target to systemd-networkd-resolvconf-update.service to ensure we update /etc/resolv.conf with DNS config prior to reaching network-online.target. Regression potential: Low. networkd is not widely being used outside of netplan/snappy in xenial. + Test Case: + lxc launch ubuntu-daily:xenial x1 + lxc exec x1 /bin/bash - Test Case: - lxc launch ubuntu-daily:xenial x1 - lxc exec x1 /bin/bash + # make sure you're on systemd-229-4ubuntu13 + apt update && apt install -y systemd - # make sure you're on systemd-229-4ubuntu13 - apt update && apt install -y systemd - - # enable networkd and netplan - apt install -y nplan + # enable networkd and netplan + apt install -y nplan cat <<EOF > /etc/netplan/nplan.yaml network: - version: 2 - ethernets: - eth0: - dhcp4: true + version: 2 + ethernets: + eth0: + dhcp4: true EOF - sed -i.orig -e 's/^source/# source/' /etc/network/interfaces - - netplan generate - - # make sure cloud-init.service uses networkd - sed -i.orig -e '/After=networking.service/a After=systemd-network-wait-online.service' /lib/systemd/system/cloud-init.service + sed -i.orig -e 's/^source/# source/' /etc/network/interfaces - reboot + netplan generate - # check that the order of execution with: - journalctl -o short-precise --unit resolvconf.service --unit network-online.target --unit systemd-networkd-wait-online.service --unit systemd-networkd-resolvconf-update.service + # make sure cloud-init.service uses networkd + sed -i.orig -e '/After=networking.service/a After=systemd-networkd-wait-online.service' /lib/systemd/system/cloud-init.service - # the order should be: - 1. resolvconf: systemd[1]: Started Nameserver information manager. - 2. systemd-networkd-wait-online.service: systemd[1]: Starting Wait for Network to be Configured... - 3. systemd-networkd-resolvconf-update.service: systemd[1]: Started Update resolvconf for networkd DNS. - 4. network-online.target: systemd[1]: Reached target Network is Online. + reboot + + # check that the order of execution with: + journalctl -o short-precise --unit resolvconf.service --unit network-online.target --unit systemd-networkd-wait-online.service --unit systemd-networkd-resolvconf-update.service + + # the order should be: + 1. resolvconf: systemd[1]: Started Nameserver information manager. + 2. systemd-networkd-wait-online.service: systemd[1]: Starting Wait for Network to be Configured... + 3. systemd-networkd-resolvconf-update.service: systemd[1]: Started Update resolvconf for networkd DNS. + 4. network-online.target: systemd[1]: Reached target Network is Online. === BAD OUTPUT === On a failing system, Reached target Network is Online occurs before (1, 2, or 3) above, like this output: Dec 15 19:18:15.233443 x4 systemd[1]: Started Nameserver information manager. Dec 15 19:18:15.797857 x4 systemd[1]: Starting Wait for Network to be Configured... Dec 15 19:18:15.799573 x4 systemd-networkd-wait-online[145]: ignoring: lo Dec 15 19:18:15.804949 x4 systemd-networkd-wait-online[145]: ignoring: lo Dec 15 19:18:15.805079 x4 systemd-networkd-wait-online[145]: ignoring: lo Dec 15 19:18:29.100305 x4 systemd[1]: Starting Update resolvconf for networkd DNS... Dec 15 19:18:29.101870 x4 systemd[1]: Started Wait for Network to be Configured. Dec 15 19:18:29.102144 x4 systemd[1]: Reached target Network is Online. Dec 15 19:18:29.212842 x4 systemd[1]: Started Update resolvconf for networkd DNS. - === GOOD OUTPUT === On a passing system, Reached target Network is Online occurs after 1, 2, and 3. Dec 15 19:28:42.548545 x4 systemd[1]: Started Nameserver information manager. Dec 15 19:28:43.144389 x4 systemd[1]: Starting Wait for Network to be Configured... Dec 15 19:28:43.146155 x4 systemd-networkd-wait-online[145]: ignoring: lo Dec 15 19:28:56.081487 x4 systemd[1]: Started Wait for Network to be Configured. Dec 15 19:28:56.100353 x4 systemd[1]: Starting Update resolvconf for networkd DNS... Dec 15 19:28:56.124005 x4 systemd[1]: Started Update resolvconf for networkd DNS. Dec 15 19:28:56.124555 x4 systemd[1]: Reached target Network is Online. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1649931 Title: systemd-networkd needs to ensure DNS is up before network- online.target To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/resolvconf/+bug/1649931/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs