After reading a bit more about this issue, I can see where the conflict happens:
1/ systemd requires any container manager to mount /sys read-only, according to https://systemd.io/CONTAINER_INTERFACE/ in order to make udevd behave properly. 2/ NetworkManager checks for /sys to be read-only in order to decide if it should not be using udev 3/ lxc has a different understanding (and requirements), so it mounts /sys r/w, leading to confusion in NetworkManager. => IMO NetworkManager needs to do an improved check if it is running inside a container (in addition to https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/commit/78dc57d8f4af1a230053473f3eb7c18d1eaf0730) as the /sys read-only check is not enough for the LXC environment. Maybe NM could be extended to check for something like "systemd-detect-virt --container == 0" and not use udev in this case? -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to network-manager in Ubuntu. https://bugs.launchpad.net/bugs/1936312 Title: nm-online times out, failing autopkgtests Status in network-manager package in Ubuntu: Fix Released Bug description: The nm-online util does not return successfully as of 1.32.2-0ubuntu1 (currently in impish-proposed). systemd VS network-manager autopkgtests (in LXD) fail, because the autopkgtest-virt-lxd runner tries to wait for "network ready" before it is reconnecting after a reboot. This happens by checking the 'systemctl start network-online.target' command, in turn executing the 'nm-online -s -q' util (via NetworkManager-wait-online.service), in addition to systemd-networkd-wait-online.service (which seems to be working OK). nm-online does not return successfully anymore as of 1.32.2-0ubuntu1, but it times out. That is a regression compared to v1.30. Reproducer: $ lxc launch ubuntu-daily:impish test $ lxc exec test bash # apt install network-manager #(version 1.30.0-1ubuntu4) # time systemctl start network-online.target real 0m0.071s user 0m0.021s sys 0m0.023s # time nm-online -s Connecting............... 30s [started] real 0m0.043s user 0m0.027s sys 0m0.006s root@test:~# echo $? 0 Everything is OK up to here. # vim /etc/apt/sources.list #(enable impish-proposed) # apt update && apt install network-manager #(1.32.2-0ubuntu1) # time nm-online -s Connecting............... 0s [startup-pending] real 0m30.019s user 0m0.021s sys 0m0.014s # time systemctl start network-online.target real 1m0.104s user 0m0.013s sys 0m0.023s # journalctl -u NetworkManager | grep startup Jul 15 09:05:06 test NetworkManager[1912]: <info> [1626339906.6507] manager: startup complete root@test:~# NetworkManager -V 1.32.2 root@test:~# nm-online -s Connecting............... 0s [startup-pending] root@test:~# echo $? 1 root@test:~# nm-online Connecting............... 0s [offline] root@test:~# echo $? 1 The journal log contains the "startup completed" line, so 'nm-online -s' should return immediately. But as we can see, nm-online fails (after a timeout) and thus blocks network-online.target, failing the systemd autopkgtests (in LXD). To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1936312/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
