[Impact]
Users who modify one of several settings via the `pro config` sub command will be unwittingly changing the contents of a conffile. Those changes could then cause a conffile prompt next time they upgrade u-a-t (if we changed the default conffile).
These settings are intended to be easily modified by the user in normal circumstances, so conffile prompts caused by them are unnecessary and concerning to the end-user.
The fix is to migrate these settings out of the conffile into a separate not-conffile that is managed by the `pro config` subcommand only. This file will live in /var/lib/ubuntu-advantage.
[Test Case]
We will run a script that exercises the following scenarios:
* normal upgrade with no uaclient.conf changes
* verify: no conffile prompts
* verify: no warnings/errors during upgrade
* verify: debsums -e ubuntu-advantage-tools is OK after upgrade
* upgrade where user had run pro config set apt_news=false
* verify: no conffile prompts
* verify: no warnings/errors during upgrade
* verify: debsums -e ubuntu-advantage-tools is OK after upgrade
* verify: modified settings are preserved in new user-config.json
* upgrade where user had modified uaclient.conf settings that will
remain in uaclient.conf after the migration
* verify: no conffile prompts
* verify: no warnings/errors during upgrade
* verify: modified uaclient.conf settings are preserved in
new uaclient.conf
* upgrade where the user has a corrupted uaclient.conf
* verify: no conffile prompts
* verify: warning during upgrade
* verify: pre-upgrade uaclient.conf is preserved after upgrade
for the following version upgrade paths (representing the two most recent versions with different default uaclient.conf files):
* 27.12 -> 27.14
* 27.13.6 -> 27.14
for the following Ubuntu releases:
* xenial
* bionic
* focal
* jammy
* kinetic
[Regression Potential]
This migration takes place at upgrade time. The logic is spread throughout preinst, postinst, and postrm. If we made mistakes here, any of the following could happen:
* failed apt upgrades
* loss of user-customized uaclient.conf settings
* unnecessary/confusing conffile prompts
[Discussion]
In theory, this migration should settle this concern for the foreseeable future. The settings that we are leaving in uaclient.conf make sense to be treated like a conffile. Future settings can be added in an appropriate place (either uaclient.conf or the new user-config) based on which category they fit in best.
We implemented several warning messages and documentation for them, even for very unlikely situations (such as if json serialization of a python dict fails or writing to a file in /var/lib fails).
We orgnanized the migration so that the user's backup file is only overwritten if everything else in the migration succeeds. This should make data loss very unlikely.
We are still supporting the settings if they are left in uaclient.conf, but there will be a warning in logs and on every future upgrade of u-a-t.
[Original Description]
In order to fix 2003977 and 2004279 we introduced a temporary solution in preinst/postinst/postrm to avoid unneeded conffile prompts. This solution was intended to be temporary.
The real solution will be to move settings that should not be tracked in a conffile somewhere else (notably apt_news, but some others as well).
This bug was fixed in the package ubuntu-
---------------
ubuntu-
* d/ubuntu-
- migrate certain settings out of uaclient.conf to a new file managed by
the pro config subcommand (LP: #2004280)
* d/ubuntu-
- refactor PREVIOUS_PKG_VER as a global variable
- simplify how we add notices
* New upstream release 27.14 (LP: #2011477)
- api: new u.unattended_
unattended upgrades
- apt:
+ remove legacy apt-hook
+ deliver json apt-hook for interim releases
+ fix cloud identification logic in json apt-hook
+ make all calls to esm-cache isolated from system configuration
(LP: #2008280)
+ only set up the esm cache on supported systems (LP: #2004018)
- fix:
+ format the output to be more readable (LP: #1926182)
+ add option to attach during a fix without a token
+ verify if fixed version can be installed before trying (LP: #2006705)
- livepatch: show warning if current kernel is not supported
- locks: alert user about corrupted lock files (LP: #1996931)
- logging: logs are now formatted as jsonlines
- motd: remove esm-apps announcement
- notices: new representation on disk as separate files (LP: #1987738)
- realtime: remove ubuntu-realtime package on disablement
- status:
+ removed contract info update check network call
+ no longer includes warnings about notices when non-root (LP: #2006138)
+ unattached status sends virt type to contract server for better
resource availability calculation
- timer jobs: add daily job to check for contract updates
- yaml: always import distro-provided pyyaml (LP: #2007234, LP: #2007241)
-- Grant Orndorff <email address hidden> Mon, 13 Mar 2023 15:28:33 -0400