postfix warns about differing chroot files after package upgrades

[Martin Richtarsky]

postfix will warn when the chroot binaries (or certificate/settings files) differ, which happens when the system version was updated.

Could an updtae hook be added, so the chroot is also updated alongside any system udates?

Jan 14 09:00:02 mail postfix/postfix-script[1703958]: warning: /var/spool/postfix/lib/x86_64-linux-gnu/libnss_systemd.so.2 and /lib/x86_64-linux-gnu/libnss_systemd.so.2 differ

ProblemType: Bug
DistroRelease: Ubuntu 21.04
Package: postfix 3.5.6-1ubuntu0.2
ProcVersionSignature: Ubuntu 5.11.0-44.48-generic 5.11.22
Uname: Linux 5.11.0-44-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu65.4
Architecture: amd64
CasperMD5CheckResult: unknown
Date: Fri Jan 14 09:22:08 2022
RebootRequiredPkgs: Error: path contained symlinks.
SourcePackage: postfix
UpgradeStatus: Upgraded to hirsute on 2021-07-17 (180 days ago)

[Scott Kitterman (kitterman)]

Does restarting (not reloading) or stopping/starting postfix get things back in sync?

[Martin Richtarsky (mrichtarsky)]

@Scott: Yes it does (I did both and don't get the error anymore)

Could that be done automatically when the chroot file dependencies change?

[Scott Kitterman (kitterman)]

In theory, yes. In practice, it would be very complicated and it's not something that's likely to get done in the near-term.

[Amit (amit777)]

Hi, we are experiencing these warnings, and restarting postfix does not seem to resync the files. Using Ubuntu 22.04.2.

When restarting, which script is supposed to do the check and re-copy? Any guidance on where to look would be appreciated. I checked in postfix's IRC channel, and I'm told that postfix is not supposed to copy any files, so I'm confused if the files are copied by an Ubuntu/Debian specific script.

[Scott Kitterman (kitterman)]

The the copying is done by Debian/Ubuntu specific changes for better integration with the overall operating system. If you stop and then start postfix (not restart), does that solve it? If not, what specific files are the issue?

[Amit (amit777)]

Thanks for that clarification!

THe files we had warnings about were fixed with:

cp -p /etc/hosts /var/spool/postfix/etc/hosts
cp -p /lib/x86_64-linux-gnu/libnss3.so /var/spool/postfix/lib/x86_64-linux-gnu/libnss3.so
cp -p /lib/x86_64-linux-gnu/libnss_systemd.so.2 /var/spool/postfix/lib/x86_64-linux-gnu/libnss_systemd.so.2
cp -p /lib/x86_64-linux-gnu/libnssutil3.so /var/spool/postfix/lib/x86_64-linux-gnu/libnssutil3.so
cp -p /etc/localtime /var/spool/postfix/etc/localtime

Next time I see this, I will try to stop and start. If it doesn't work, I will report more details.
 Thanks again.