As I mentioned in the upstream systemd bug, it's still not clear what exactly is causing this, and the inability to reproduce it after the image first boot, or with another image with debug added, or with the latest image, means it will be impossible to verify any fix to this problem.
However, my best guess is udevd is somehow missing the 'add' uevent for the network device, as I described in the upstream bug. While I don't know why it would miss the event, the upstream commit e0e789c1e97e2cdf1cafe0c6b7d7e43fa054f151 should fix the problem, as it will setup the proper udevd device parameters not only for 'add' but also 'change' uevents. So, based on those assumptions/guesses and on the relative safety of the upstream commit, I plan to SRU that commit for this bug. ** Bug watch added: github.com/systemd/systemd/issues #17532 https://github.com/systemd/systemd/issues/17532 ** Also affects: systemd via https://github.com/systemd/systemd/issues/17532 Importance: Unknown Status: Unknown -- 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/1902960 Title: Upgrade from 245.4-4ubuntu3.3 to 245.4-4ubuntu3.2 appears to break DNS resolution in some cases Status in cloud-images: New Status in systemd: Unknown Status in cloud-init package in Ubuntu: Confirmed Status in systemd package in Ubuntu: Incomplete Bug description: The systemd upgrade 245.4-4ubuntu3.3 to 245.4-4ubuntu3.2 appears to have broken DNS resolution across much of our Azure fleet earlier today. We ended up mitigating this by forcing reboots on the associated instances, no combination of networkctl reload, reconfigure, systemctl daemon-reexec, systemctl daemon-reload, netplan generate, netplan apply would get resolvectl to have a DNS server again. The main symptom appears to have been systemd-networkd believing it wasn't managing the eth0 interfaces: ubuntu@machine-1:~$ sudo networkctl IDX LINK TYPE OPERATIONAL SETUP 1 lo loopback carrier unmanaged 2 eth0 ether routable unmanaged 2 links listed. Which eventually made them lose their DNS resolvers: ubuntu@machine-1:~$ sudo resolvectl dns Global: Link 2 (eth0): After rebooting, we see this behaving properly: ubuntu@machine-1:~$ sudo networkctl list IDX LINK TYPE OPERATIONAL SETUP 1 lo loopback carrier unmanaged 2 eth0 ether routable configured 2 links listed. ubuntu@machine-1:~$ sudo resolvectl dns Global: Link 2 (eth0): 168.63.129.16 This appears to be specifically linked to the upgrade, i.e. we were able to provoke the issue by upgrading the systemd package, so I suspect it's part of the packaging in the upgrade process. --- ProblemType: Bug ApportVersion: 2.20.11-0ubuntu27.10 Architecture: amd64 CasperMD5CheckResult: skip DistroRelease: Ubuntu 20.04 Lspci-vt: -[0000:00]-+-00.0 Intel Corporation 440BX/ZX/DX - 82443BX/ZX/DX Host bridge (AGP disabled) +-07.0 Intel Corporation 82371AB/EB/MB PIIX4 ISA +-07.1 Intel Corporation 82371AB/EB/MB PIIX4 IDE +-07.3 Intel Corporation 82371AB/EB/MB PIIX4 ACPI \-08.0 Microsoft Corporation Hyper-V virtual VGA Lsusb: Error: command ['lsusb'] failed with exit code 1: Lsusb-t: Lsusb-v: Error: command ['lsusb', '-v'] failed with exit code 1: MachineType: Microsoft Corporation Virtual Machine Package: systemd 245.4-4ubuntu3.3 PackageArchitecture: amd64 ProcEnviron: TERM=xterm-256color PATH=(custom, no user) LANG=C.UTF-8 SHELL=/bin/bash ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-1031-azure root=PARTUUID=2e08bba3-68b4-4a16-af3b-47b73bd138a9 ro console=tty1 console=ttyS0 earlyprintk=ttyS0 panic=-1 ProcVersionSignature: Ubuntu 5.4.0-1031.32-azure 5.4.65 Tags: focal uec-images Uname: Linux 5.4.0-1031-azure x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: N/A _MarkForUpload: True dmi.bios.date: 12/07/2018 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 090008 dmi.board.name: Virtual Machine dmi.board.vendor: Microsoft Corporation dmi.board.version: 7.0 dmi.chassis.asset.tag: 7783-7084-3265-9085-8269-3286-77 dmi.chassis.type: 3 dmi.chassis.vendor: Microsoft Corporation dmi.chassis.version: 7.0 dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr090008:bd12/07/2018:svnMicrosoftCorporation:pnVirtualMachine:pvr7.0:rvnMicrosoftCorporation:rnVirtualMachine:rvr7.0:cvnMicrosoftCorporation:ct3:cvr7.0: dmi.product.name: Virtual Machine dmi.product.uuid: 4412ad79-83fa-f845-b7c2-6f30dd4f1950 dmi.product.version: 7.0 dmi.sys.vendor: Microsoft Corporation To manage notifications about this bug go to: https://bugs.launchpad.net/cloud-images/+bug/1902960/+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
