Public bug reported: If a system only has DNS server info via open-iscsi (putting aside whether or not that's a good idea), and then starts a Docker container or LXD container, name resolution breaks.
The open-iscsi udev rules invokes net-interface-handler when a network device is added or removed. This helper deals with dns resolution. On boot, this sets up dns resolution based on the information gathered during early boot. However: 1) The udev rule and script run the full script for all network interfaces, whether or not they are the iscsi interface - they do not bail out early if there is a mismatch. So, the removal of any device triggers 'net-interface-handler stop', which removes the /run/resolvconf/interface/ethX.iscsi-target file, breaking resolution. This occurs even if the interface being removed is *not* ethX. 2) For some reason, both starting a docker container and starting an LXD container involve adding 2 interfaces and then removing one. The additions do nothing, as the resolution rule has already been installed. The removal, however, causes the resolution rule to be removed, breaking DNS. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: open-iscsi 2.0.873+git0.3b4b4500-14ubuntu3.4 ProcVersionSignature: Ubuntu 4.4.0-98.121-generic 4.4.90 Uname: Linux 4.4.0-98-generic x86_64 ApportVersion: 2.20.1-0ubuntu2.10 Architecture: amd64 Date: Wed Nov 15 05:19:12 2017 ProcEnviron: TERM=xterm-256color PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: open-iscsi UpgradeStatus: No upgrade log present (probably fresh install) mtime.conffile..etc.iscsi.iscsid.conf: 2017-10-20T20:38:27.028134 ** Affects: open-iscsi (Ubuntu) Importance: Undecided Status: Confirmed ** Tags: apport-bug uec-images -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1732342 Title: DNS info removed when any interface removed, not just iSCSI interface To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/open-iscsi/+bug/1732342/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs