Bug in /etc/update-motd.d/50-landscape-sysinfo script - incorrect variable used for load threshold calculation

[Markus]

[ Impact ]

 * The CPU load is incorrectly calculated, and users won't get system info in
the message-of-the-day (motd).

 * The `cores` variable was misnamed; it should be `CORES` since bash variables are case-sensitive

* Affects landscape-client on noble, mantic, jammy, and focal.

[ Test Plan ]

Steps to Reproduce:

    1. Open the /etc/update-motd.d/50-landscape-sysinfo script.
    2. Notice the line where THRESHOLD is set: THRESHOLD="${cores:-1}.0".
    3. The correct variable should be CORES instead of cores.

To trigger MOTD and view incorrect calculation:

sudo run-parts /etc/update-motd.d/
Notice message: " System information disabled due to load higher than 1.0" even on systems with multiple cores.

[ Where problems could occur ]

 * This fix will necessarily run the system process info on more systems during MOTD. If the CPU load threshold was poorly chosen, then overly-loaded systems might be slow during MOTD while landscape-sysinfo runs

[Spencer Runde (spencerrunde)]

Hi Markus,

Thank you for your bug report. We have an SRU in progress for this, and it should land shortly.

[Spencer Runde (spencerrunde)]

Original bug report:

===

There is a bug in the /etc/update-motd.d/50-landscape-sysinfo (Symlink to /usr/share/landscape/landscape-sysinfo.wrapper) script in Ubuntu. The script incorrectly sets the load threshold due to a typo, causing the system information to be disabled unnecessarily when the system load is actually within acceptable limits.

Steps to Reproduce:

    1. Open the /etc/update-motd.d/50-landscape-sysinfo script.
    2. Notice the line where THRESHOLD is set: THRESHOLD="${cores:-1}.0".
    3. The correct variable should be CORES instead of cores.

Expected Behavior:
The threshold should be calculated based on the number of CPU cores, e.g., THRESHOLD="${CORES:-1}.0", and system information should be displayed correctly when the load is below this threshold.

Actual Behavior:
The threshold is incorrectly set to 1.0 due to the typo, causing system information to be disabled unnecessarily.

Version Information:

    Ubuntu 24.04 LTS: landscape-common 24.02-0ubuntu5
    Ubuntu 22.04.4 LTS: landscape-common 23.02-0ubuntu1~22.04.2

[Simon Chopin (schopin)]

Hi!

Whats the status on the Oracular fix? The MP has the 'Superseded' status but I don't see anything regarding this issue in the changelog.

[Spencer Runde (spencerrunde)]

Hi Simon,

It doesn't look like the relevant change is present in ubuntu/devel: https://git.launchpad.net/ubuntu/+source/landscape-client/tree/debian/landscape-sysinfo.wrapper

I'm not sure why that MP got marked as 'superseded'. We will want this fix in Oracular as well.

[Dan Bungert (dbungert)]

Hi Spencer, thanks for SRUing this fix.

I have elected to upload to f/j/m/n/o series with the following corrections:
* ubuntu/devel targetted branch needed series updated for oracular, and a
  simple merge
* all the rest needed version number corrections - I suggest having a look at
  https://wiki.ubuntu.com/SecurityTeam/UpdatePreparation#Update_the_packaging
  which outlines the version number scheme and the reasons. In the case of
  your mantic/noble proposals, those uploads would have been rejected because
  landscape-client version 23.08-0ubuntu2 and 24.02-0ubuntu6 have been uploaded
  previously. The focal / jammy ones had plausible version numbers but I have
  updated them to more closely match what's suggested on the wiki.
* the format of debian/changelog wants a certain date stamp format (month and
  day were flipped), consider using `dch -i` to add the entry, or `date -R` can
  also help. `dch` will also help with the version number increment.

[Launchpad Janitor (janitor)]

This bug was fixed in the package landscape-client - 24.02-0ubuntu9

---------------
landscape-client (24.02-0ubuntu9) oracular; urgency=medium

  * d/landscape-sysinfo.wrapper: fix 'cores' variable to CORES in message-
    of-the-day load threshold calculation (LP: #2066983)

 -- Spencer Runde <email address hidden> Tue, 28 May 2024 14:19:00 -0500

[Timo Aaltonen (tjaalton)]

Hello Markus, or anyone else affected,

Accepted landscape-client into noble-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/landscape-client/24.02-0ubuntu5.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-noble to verification-done-noble. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-noble. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Timo Aaltonen (tjaalton)]

Hello Markus, or anyone else affected,

Accepted landscape-client into jammy-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/landscape-client/23.02-0ubuntu1~22.04.3 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-jammy to verification-done-jammy. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-jammy. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Timo Aaltonen (tjaalton)]

Hello Markus, or anyone else affected,

Accepted landscape-client into focal-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/landscape-client/23.02-0ubuntu1~20.04.3 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-focal to verification-done-focal. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-focal. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Markus (the-markus)]

Hi Timo,

thank you very much and also thank you Spencer for fixing the bug!

I have tested the proposed package on Ubuntu Noble, Jammy & Focal using the `stress` tool to simulate high load and can confirm that the bug is fixed.