libpod: fix healthchecks not executing every interval on linux

[winterqt]

By default, systemd sets a limit of how many times a service can start, which means that if you have a healthcheck that runs more often than the limits, systemd will refuse to start it with a message like "Start request repeated too quickly." emitted to the journal.

I'm not familiar enough with the e2e test suite to confidently write a test for this -- hints appreciated! :)

Does this PR introduce a user-facing change?

Fixed a bug that prevented healthchecks from running consistently on time on Linux.

[mheon]

Good change, code LGTM
/approve

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: mheon, winterqt

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [mheon]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[mheon]

For testing, I would recommend doing something like https://github.com/containers/podman/blob/main/test/e2e/healthcheck_run_test.go#L59-L76 with a shorter interval and a runtime long enough to convince systemd to fail (or, with your patch, not fail)

[Luap99]

For testing, I would recommend doing something like https://github.com/containers/podman/blob/main/test/e2e/healthcheck_run_test.go#L59-L76 with a shorter interval and a runtime long enough to convince systemd to fail (or, with your patch, not fail)

test/e2e does never run healtchecks via systemd timers, they get disabled there via env var.
This would need to go into test/system/220-healthcheck.bats. But keep in mind any timing related test will be flaky so it would need to be done in a way that it doesn't depend on timings, i.e. sleep or other waiting commands ideally.

[winterqt]

Unfortunately having some trouble running the system tests on my work machine :(

Can try to write a test and run it through CI if y'all would be fine with that?

[packit-as-a-service]

Cockpit tests failed for commit 191bbff. @martinpitt, @jelly, @mvollmer please check.

[packit-as-a-service]

[NON-BLOCKING] Packit jobs failed. @containers/packit-build please check. Everyone else, feel free to ignore.

[mheon]

Sure, if you can't get the tests to run