obs-build mangles entrypoint/cmd breaking podman's systemd recognition when building from Dockerfiles

[dcermak]

If you build a container from a Dockerfile in the Open Build Service and specify systemd as the CMD or ENTRYPOINT as follows:

CMD /usr/lib/systemd/systemd

then you obtain the following entry in the container inspect:

        "Config": {
            "Cmd": [
                "/bin/sh",
                "-c",
                "/usr/lib/systemd/systemd"
            ]
         }

Unfortunately, this breaks podman's systemd detection, which relies on the config looking like this:

        "Config": {
            "Cmd": [
                "/usr/lib/systemd/systemd"
            ]
         }

So in a nutshell, if you create a systemd-container from a Dockerfile, then you have to always add --systemd=always, otherwise the image will fail to start with the rather unhelpful message:

🕙[ 16:43:33 ] ❯ podman run --rm -it localhost/me/init:latest
Failed to mount tmpfs at /run: Operation not permitted
[!!!!!!] Failed to mount API filesystems.
Exiting PID 1...

[dcermak]

Nevermind, my bad. This is an upstream issue containers/podman#13324