Does a live ISO with no embedded Ignition config have a hidden Ignition file?

[erik@fedora32 ~]$ coreos-installer iso show fedora-coreos-32.20200625.1.0-live.x86_64.iso
Error: No embedded Ignition config.
[erik@fedora32 ~]$ 

Behind the scenes, is there any Ignition file that represents the default behavior?
Is it available somewhere?
(Preferably in the format of a human readable Fedora CoreOS Config that could be
translated by /usr/bin/fcct)
Such a file would be a good starting point, if you just want to make a minimal modification of the default behavior.

Yes…but it’s much more minimal than you might expect: https://github.com/coreos/fedora-coreos-config/blob/testing-devel/overlay.d/10coreuser/usr/lib/dracut/modules.d/40ignition-conf/base.ign

Doesn’t the existing documentation in e.g. fcct address the use case of examples?

I see different behaviors between an unmodified fedora-coreos-32.20200625.1.0-live.x86_64.iso
and one where the Ignition file

https://github.com/coreos/fedora-coreos-config/blob/testing-devel/overlay.d/10coreuser/usr/lib/dracut/modules.d/40ignition-conf/base.ign

has been embedded. The unmodified one boots up into a shell but the modified one boots up to a login prompt.

The scenario I am thinking about is when a user is happy with the default behavior of the live ISO but just wants to make a small adjustment. In such a situation it would be convenient to be able to start editing from an Ignition file that represents the default behavior.

I see there is an example about autologin. Yes, that will probably help me get autologin back.

Autologin is intentionally only enabled if you don’t specify an Ignition config. It’s intended for casual experimentation with a Fedora CoreOS system. If you’re explicitly provisioning the machine and want autologin, you can enable it using an Ignition config, as you found.