

FWIW, your domain will most likely eventually get used by spammers and then it’ll be an endless string of somewhat expected but unpredictable failures from there on onwards, with no actions you can take to reduce it. It’s good to keep an eye on what comes in but I wouldn’t invest too much effort into failure alerting.
PUID
is indeed handled inside the container itself, it’ll run a container-provided script as whatever the container’s UID 0 happens to be first which then drops to whatever$PUID
happens to be inside the container.user=
is enforced by Podman itself before the container starts, but Podman will still run as root in that setup. That means Podman is running “rootful”, while if you started the container manually as $uid using the regular Podman CLI, it would be “rootless”. That is a major difference in a lot of respects, including security, and you can find quite a bit of documentation on the differences between those operating modes online; it wouldn’t fit in a comment. Rootless is generally considered the better mode, though there are some things that still require a rootful container.In the upcoming NixOS 25.05 or current unstable, there are some tools you can use to run containers rootless as another user more easily using a new
$name.podman.user = "";
setting. From what I understand they’ll still be root-managed systemd system services that require sudo to operate, but that means privileges get dropped by systemd before running Podman, instead of dropped by Podman before running the container. This stuff is recent and I haven’t used it, I just happen to know it exists, relevant nixpkgs commit if you wanna dig into it yourself: https://github.com/NixOS/nixpkgs/commit/7d443d378b07ad55686e9ba68faf16802c030025