container,inspect: convert Entrypoint to an array instead of a string

[flouthoc]

Convert container entrypoint from string to an array inorder to make
sure there is parity between podman inspect <ctr> and docker inspect <ctr>

Closes: #13803

[vrothberg]

LGTM
It's a breaking change but Docker-compat turns it into a fix :^)

[rhatdan]

/approve
/lgtm
/hold

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: flouthoc, rhatdan

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 [flouthoc,rhatdan]

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

[rhatdan]

/lgtm

[flouthoc]

@containers/podman-maintainers PTAL

[jwhonce]

/hold cancel

[Luap99]

I just noticed that this breaks our own libpod api while running @baude new machine test. The inspect struct is send over the wire, should we revert this?!

[flouthoc]

@Luap99 I'm okay if we revert this but shouldn't we fix the test then as this is needed for docker compatibility ? anyways I don't have a strict opinion on this so If this is blocker then no issues in reverting this but we might need this at some point and we will have to fix the tests then.

[Luap99]

docker compat vs podman comapt? At some point we should accept that there are also podman users who use this.
This breaks every 4.0 vs 4.1 compat via the remote api
Error: json: cannot unmarshal string into Go struct field InspectContainerConfig.Config.Entrypoint of type []string and this failed on a podman-remote run for some reason so this is very bad.

If we take semver seriously we cannot change this until 5.0

[flouthoc]

@Luap99 I think we should get this in 5.0 it would be better there if this breaking remote 4.0 vs 4.1 api as of now.

[rhatdan]

The question is what is more important Docker Compatibility or Podman compatibility.

[flouthoc]

@rhatdan I'm not sure what would be a priority here but it looks like this is breaking exisiting compat api users who are using 4.0 client against 4.1 server. Is that right @Luap99 ?

[flouthoc]

@rhatdan @Luap99 a PR here is we decide to revert this #13963

[rhatdan]

Can we do the newer change in just Docker API?

[flouthoc]

@rhatdan Original issue requested a fix on podman side so only fixing it for docker API might not be enough so I guess it should be good for 5.0.