document --service-container on podman-kube-play

[erdnaxeli]

This flag was added on Podman v4.4.0 but was not documented.

Does this PR introduce a user-facing change?

Document `--service-container` on podman-kube-play

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[erdnaxeli]

I just read this:

  // Below flags are local-only and hidden since they are used in
  // kube-play's systemd integration only and hence hidden from
  // users.

As this flag can be seen with systemctl status (example below) I think it should be documented anyway.

× someservice.service - Some Service
     Loaded: loaded (/home/podman/.config/containers/systemd/someservice.kube; generated)
     Active: failed (Result: exit-code) since Thu 2025-03-27 14:19:38 UTC; 48min ago
    Process: 2361448 ExecStart=/usr/bin/podman kube play --replace --service-container=true /home/podman/someservice/kube.yaml (code=exited, status=125)
    Process: 2361838 ExecStopPost=/usr/bin/podman kube down /home/podman/someservice/kube.yaml (code=exited, status=0/SUCCESS)
   Main PID: 2361448 (code=exited, status=125)
        CPU: 1.292s

[Luap99]

The reason we hide because we only use it for the systemd integration and don't expect users to use that directly as such it is hidden.

It is not stable as we can change it anytime what it does internally. As such I don't think it should be documented. If it would be it would have to sat it is not stable and not supposed to be used outside of systemd.

[erdnaxeli]

I understand why it is hidden, but I saw it in the output of systemctl status and I was wondering what it does. I found no documentation in the manpage, and I finally found the changelog which is the only mention of it.

[github-actions]

A friendly reminder that this PR had no activity for 30 days.

[danishprakash]

It'd be a good idea to document it, even if it's a flag not intended for end users. But as @Luap99 suggested, if we choose to document this, we should mention the fact that it's meant for systemd integration and perhaps that it's subject to changes as well.