I do this on the minimal Debian release which is essentially coming from the same place, you’re left to get things configured with a root user or maybe a privileged user after install. There’s a few things to tweak for rootless podman and it will vary based on the distro. The gist for me and Debian is:

1. make an unprivileged account for running podman containers
2. enable linger so i can use systemd with this account and the running of the containers
3. allow lower ports for podman rootless in sysctl (for example, 80 if you’re running basic http services rootless), net.ipv4.ip_unprivileged_port_start=<start of lower range of ports rootless containers will use>
4. run containers with the appropriate --userns flags. This can vary a lot depending on the container. Some maintainers are nice and ensure the internal uid/gid is something expected like 1000, sometimes not and you have to fire it up and figure out the app account name, uid/gid. An example I’ll put here is a podman run snippet for running jenkins (official image from cloudbees) rootless:

podman run --name jenkins --user jenkins --userns=keep-id:uid=1000,gid=1000 …

Again, that’s just Debian, never tried MicroOS, but if MicroOS isn’t doing anything special to accommodate rootless podman I imagine these steps are somewhat applicable. One issue I ran into was with an older version of Podman, whatever comes with Ubuntu 22: That version of podman requires you to set the namespace mappings; Debian 12’s version does not and the --userns=keep… flag just works.