[Bug 2043820] Re: Unable to contact snap store on Xubuntu from Jammy to Noble

[Nick Rosbrook]

I have verified the fix using ubuntu-release-upgrader from noble-
proposed using a xubuntu 22.04 VM:

ubuntu at xubuntu:~$ sudo sed -i 's/Prompt=lts/Prompt=normal/g' /etc/update-manager/release-upgrades
[sudo] password for ubuntu: 
ubuntu at xubuntu:~$ do-release-upgrade --proposed
Checking for a new Ubuntu release

= Welcome to Ubuntu 24.04 LTS 'Noble Numbat' =

The Ubuntu team is proud to announce Ubuntu 24.04 LTS 'Noble Numbat'.

To see what's new in this release, visit:
  https://wiki.ubuntu.com/NobleNumbat/ReleaseNotes

[ ...SNIP... ]

In another terminal, while the upgrade was running:

ubuntu at xubuntu:~$ cat /etc/resolv.conf 
# This is /run/systemd/resolve/resolv.conf managed by man:systemd-resolved(8).
# Do not edit.
#
# This file might be symlinked as /etc/resolv.conf. If you're looking at
# /etc/resolv.conf and seeing this text, you have followed the symlink.
#
# This is a dynamic resolv.conf file for connecting local clients directly to
# all known uplink DNS servers. This file lists all configured search domains.
#
# Third party programs should typically not access this file directly, but only
# through the symlink at /etc/resolv.conf. To manage man:resolv.conf(5) in a
# different way, replace this symlink by a static file or a different symlink.
#
# See man:systemd-resolved.service(8) for details about the supported modes of
# operation for /etc/resolv.conf.

nameserver 10.19.111.1
nameserver fd42:3cda:638d:a9b3::1
nameserver fe80::216:3eff:fe07:85b6%2
search lxd
ubuntu at xubuntu:~$ cat /run/systemd/resolved.conf.d/dist-upgrade-no-stub-resolver.conf 
# Temporarily disable stub resolver during upgrade
[Resolve]
DNSStubListener=no
ubuntu at xubuntu:~$ tail /var/log/dist-upgrade/main.log 
2024-08-12 16:21:57,233 DEBUG dir '/tmp' needs '0.0' of '<DistUpgrade.DistUpgradeCache.MyCache.checkFreeSpace.<locals>.FreeSpace object at 0x731e8275c940>' (14185896140.600000)
2024-08-12 16:21:57,233 DEBUG dir '/usr' needs '0.0' of '<DistUpgrade.DistUpgradeCache.MyCache.checkFreeSpace.<locals>.FreeSpace object at 0x731e8275c940>' (14185896140.600000)
2024-08-12 16:21:57,233 DEBUG Found writable ESP /dev/sda1 /boot/efi vfat rw,relatime,fmask=0077,dmask=0077,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro 0 0
2024-08-12 16:21:57,242 DEBUG quirks: running StartUpgrade
2024-08-12 16:21:57,242 DEBUG running Quirks.StartUpgrade
2024-08-12 16:21:57,243 DEBUG skipping 'README' (no '.')
2024-08-12 16:21:57,244 DEBUG killing update-notifier
2024-08-12 16:21:57,248 DEBUG killing kblueplugd kbluetooth4
2024-08-12 16:21:57,251 DEBUG Disabling systemd-resolved stub resolver during upgrade
2024-08-12 16:21:57,354 INFO cache.commit()

And after the upgrade was complete:

ubuntu at xubuntu:~$ apt policy chromium-browser
chromium-browser:
  Installed: 2:1snap1-0ubuntu2
  Candidate: 2:1snap1-0ubuntu2
  Version table:
 *** 2:1snap1-0ubuntu2 500
        500 http://us.archive.ubuntu.com/ubuntu noble/universe amd64 Packages
        100 /var/lib/dpkg/status
ubuntu at xubuntu:~$ snap info chromium
name:      chromium
summary:   Chromium web browser, open-source version of Chrome
publisher: Canonical✓
store-url: https://snapcraft.io/chromium
contact:   https://bugs.launchpad.net/ubuntu/+source/chromium-browser/+bugs?field.tag=snap
license:   unset
description: |
  An open-source browser project that aims to build a safer, faster, and more
  stable way for all Internet users to experience the web.
commands:
  - chromium.chromedriver
  - chromium
snap-id:      XKEcBqPM06H1Z7zGOdG5fbICuf8NWK5R
tracking:     latest/stable
refresh-date: today at 16:30 EDT
channels:
  latest/stable:    127.0.6533.99 2024-08-12 (2925) 174MB -
  latest/candidate: 127.0.6533.99 2024-08-07 (2925) 174MB -
  latest/beta:      128.0.6613.27 2024-08-08 (2926) 181MB -
  latest/edge:      129.0.6614.3  2024-07-29 (2920) 181MB -
installed:          127.0.6533.99            (2925) 174MB -


** Tags removed: verification-needed verification-needed-noble
** Tags added: verification-done verification-done-noble

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Ubuntu.
https://bugs.launchpad.net/bugs/2043820

Title:
  Unable to contact snap store on Xubuntu from Jammy to Noble

Status in firefox package in Ubuntu:
  Confirmed
Status in snapd package in Ubuntu:
  Confirmed
Status in ubuntu-release-upgrader package in Ubuntu:
  Invalid
Status in firefox source package in Noble:
  Confirmed
Status in snapd source package in Noble:
  Confirmed
Status in ubuntu-release-upgrader source package in Noble:
  Fix Committed

Bug description:
  [Impact]

  Upgrades from Jammy to Noble can fail if snap transition packages are
  installed after the new systemd has been unpacked, but before systemd-
  resolved has been unpacked.

  In practice, this manifests on at least Xubuntu upgrades during the
  chromium-browser snap transition.

  [Test Plan]

  Without this fix, the snap store connectivity check will fail when
  installing the chromium-browser snap because systemd-resolved is not
  present, so DNS lookups fail during the connectivity check.

  With the fix in place, the systemd-resolved stub resolver should be
  disabled during the upgrade so that DNS lookups succeed even when
  systemd-resolved is not yet unpacked on the system again.

  So, to test this fix, we should run an upgrade on a Xubuntu 22.04
  system:

  $ do-release-upgrade -d

  And verify that (a) the chromium-browser installation (and snap store
  connectivity check) succeeds, and (b) that the stub resolver is not in
  use during the upgrade.

  $ cat /etc/resolv.conf
  $ cat /run/systemd/resolved.conf.d/dist-upgrade-no-stub-resolver.conf

  [Where problems could occur]

  This patch disables the systemd-resolved stub resolver by writing a drop-in to
  /run/systemd/resolved.conf.d. If there was a mistake in the drop-in, it would not correctly disable the stub resolver.

  [Original Description]

  When running `do-release-upgrade -d` on Jammy Xubuntu, the upgrade
  fails consistently at the `Installing the firefox snap` step.

  This was first detected on Jenkins [1], then reproduced locally with
  `auto-upgrade-testing`, then finally by manually running a `do-
  release-upgrade -d` in a VM.

  [1]: https://platform-qa-jenkins.ps5.ubuntu.com/view/upgrade-
  list/job/upgrade_ubuntu-jammy-noble-xubuntu-amd64_qemu/7/consoleFull
  (Jenkins full log attached)

  ProblemType: Bug
  DistroRelease: Ubuntu 22.04
  Package: ubuntu-release-upgrader-core 1:22.04.17
  ProcVersionSignature: User Name 5.15.0-88.98-generic 5.15.126
  Uname: Linux 5.15.0-88-generic x86_64
  ApportVersion: 2.20.11-0ubuntu82.5
  Architecture: amd64
  CasperMD5CheckResult: unknown
  CrashDB: ubuntu
  CurrentDesktop: XFCE
  Date: Fri Nov 17 18:24:22 2023
  PackageArchitecture: all
  SourcePackage: ubuntu-release-upgrader
  Symptom: ubuntu-release-upgrader
  UpgradeStatus: No upgrade log present (probably fresh install)

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