podman machine: Adjust Chrony makestep config

[xordspar0]

This allows Chrony to update the system time when it has drifted far from NTP time. By default Chrony only makes slight adjustments, but in the case where a user's laptop lid has been shut for a while and then the machine is resumed, the VM system time could be hours or days behind real time, and it my never catch up if Chrony only makes slight changes.

Fixes #11541

Does this PR introduce a user-facing change?

Fixed a bug where podman machine VMs could have their system time drift behind real time. New machines will no longer be affected by this.

[xordspar0]

What would a test for this look like? Can you do something like podman machine init and then check that the new files are there? That's what I did in my manual testing, but I don't know if that's possible in the automated test suite.

[TomSweeneyRedHat]

@xordspar0 IDK if a test is possible, @n1hility would probably have the best answer for that. If a test isn't possible, you can use the tag [NO NEW TESTS NEEDED] in your commit description to avoid the test errors you're seeing currently.

The code LGTM, but it's way out of my wheelhouse.

[xordspar0]

I should have included a link the chrony.conf docs to make it easier on reviewers. I'm using confdir to set up a directory where I can drop a file, and in another file I setting makestep, which sets how many and how large adjustments chrony can make to the clock. The main config file already has a makestep directive, but the last one wins. I would comment out or replace the original makestep, but I don't see a way to do that with the Ignition DSL.

https://chrony.tuxfamily.org/doc/3.4/chrony.conf.html

[n1hility]

I think testing the actual time sync would be pretty complicated and likely would lead to flakes. If you do it I would definitely blow away the podman machine instance afterwords. Verifying the configs exist would be straight forward, just an enhancement to the machine tests that perhaps uses podman machine ssh to cat / Grep the files. Not sure how valuable that test would be. I’d probably just do [NO NEW TESTS NEEDED]. The change LGTM. Wdyt @baude ?

[baude]

/approve
/lgtm
/hold

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: baude, xordspar0

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[rhatdan]

/hold cancel

[ashley-cui]

/cherry-pick v4.4

[openshift-cherrypick-robot]

@ashley-cui: new pull request created: #17871

In response to this:

/cherry-pick v4.4

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