This bug is also being handled in #1805183. Comment #9 has a much better patch (along the same lines as mine but also captures STDERR from md5sum). Though it doesn't have Eoan included in the list of affected versions.
-- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1850009 Title: Issue with detecting new state in dhclient-enter-hooks.d/resolved Status in systemd package in Ubuntu: Confirmed Bug description: After upgrading to 19.10 I noticed that resolving hostnames stopped working. Quick release, which package and version info: root@caret:~# lsb_release -r Release: 19.10 root@caret:~# dpkg -S /etc/dhcp/dhclient-enter-hooks.d/resolved systemd: /etc/dhcp/dhclient-enter-hooks.d/resolved root@caret:~# apt-cache policy systemd systemd: Installed: 242-7ubuntu3 Candidate: 242-7ubuntu3 Version table: *** 242-7ubuntu3 500 500 http://au.archive.ubuntu.com/ubuntu eoan/main amd64 Packages 100 /var/lib/dpkg/status The file /etc/resolv.conf was pointing to the local instance of systemd-resolved however there was no search line, indicating something wasn't quite right. Restarting the systemd-resolved service did recreate /etc/resolv.conf with expected search line. After much debugging, I've worked out what was going wrong. The dhcp hook file /etc/dhcp/dhclient-enter-hooks.d/resolved has a bug in the resolver state change logic. This may also impact on tickets 1805183, 1832050, 1832053 and maybe others. When doing the md5sum of the old and new state, the command is wrong. It isn't sending STDOUT (and optionally STDERR) to the temp file but rather putting the md5sum command into the background and then creating an empty file for both states. Which obviously isn't different, so systemd-resolved doesn't restart. Quick diff of a working version (I'm not capturing STDERR but one can with "2>&1") ======= BEGIN PATCH ======= *** .brk-resolved-20191027 2019-10-27 11:19:56.210069032 +1030 --- resolved 2019-10-27 11:30:17.156381734 +1030 *************** *** 30,36 **** mkdir -p $statedir oldstate="$(mktemp)" ! md5sum $statedir/isc-dhcp-v4-$interface.conf $statedir/isc-dhcp-v6-$interface.conf &> $oldstate if [ -n "$new_domain_name_servers" ] ; then cat <<EOF >$statedir/isc-dhcp-v4-$interface.conf [Resolve] --- 30,36 ---- mkdir -p $statedir oldstate="$(mktemp)" ! md5sum $statedir/isc-dhcp-v4-$interface.conf $statedir/isc-dhcp-v6-$interface.conf > $oldstate if [ -n "$new_domain_name_servers" ] ; then cat <<EOF >$statedir/isc-dhcp-v4-$interface.conf [Resolve] *************** *** 55,61 **** fi newstate="$(mktemp)" ! md5sum $statedir/isc-dhcp-v4-$interface.conf $statedir/isc-dhcp-v6-$interface.conf &> $newstate if ! cmp $oldstate $newstate; then systemctl try-reload-or-restart systemd-resolved.service fi --- 55,61 ---- fi newstate="$(mktemp)" ! md5sum $statedir/isc-dhcp-v4-$interface.conf $statedir/isc-dhcp-v6-$interface.conf > $newstate if ! cmp $oldstate $newstate; then systemctl try-reload-or-restart systemd-resolved.service fi ======= END PATCH ======= Also, the script removes the script removes the $oldstate file but doesn't remove the $newstate file. Not sure how this made it through QA testing... But breaking DHCP client shouldn't happen like this. ivan. ProblemType: Bug DistroRelease: Ubuntu 19.10 Package: network-manager 1.20.4-2ubuntu2 ProcVersionSignature: Ubuntu 5.3.0-19.20-generic 5.3.1 Uname: Linux 5.3.0-19-generic x86_64 ApportVersion: 2.20.11-0ubuntu8 Architecture: amd64 Date: Sun Oct 27 11:48:33 2019 InstallationDate: Installed on 2017-04-21 (918 days ago) InstallationMedia: Ubuntu-Server 17.04 "Zesty Zapus" - Release amd64 (20170412) IpRoute: default via 172.16.1.14 dev enp0s5 150.101.89.32/28 dev enp0s5 scope link 169.254.0.0/16 dev enp0s5 scope link metric 1000 172.16.1.0/24 dev enp0s5 proto kernel scope link src 172.16.1.120 IwConfig: lo no wireless extensions. enp0s5 no wireless extensions. NetworkManager.state: [main] NetworkingEnabled=false WirelessEnabled=true WWANEnabled=true ProcEnviron: LANGUAGE=en_AU:en TERM=vt100 PATH=(custom, no user) LANG=en_AU.UTF-8 SHELL=/bin/bash RfKill: SourcePackage: network-manager UpgradeStatus: Upgraded to eoan on 2019-10-26 (0 days ago) nmcli-con: nmcli-dev: DEVICE TYPE STATE IP4-CONNECTIVITY IP6-CONNECTIVITY DBUS-PATH CONNECTION CON-UUID CON-PATH enp0s5 ethernet unmanaged unknown unknown /org/freedesktop/NetworkManager/Devices/2 -- -- -- lo loopback unmanaged unknown unknown /org/freedesktop/NetworkManager/Devices/1 -- -- -- nmcli-nm: RUNNING VERSION STATE STARTUP CONNECTIVITY NETWORKING WIFI-HW WIFI WWAN-HW WWAN running 1.20.4 connected started unknown disabled enabled enabled enabled enabled To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1850009/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
