Rootless: k3s-upgrade

[MikaelElkiaer]

Would it be possible for k3s-upgrade to support rootless k3s instances?

[brandond]

Maybe? Give it a try.

Might be hard to replace the host's k3s binary from within the unprivileged user namespace, though. Allowing it to do that (access and overwrite a file outside the isolated mount namespace) might kind of miss the point of running it rootless in the first place.

[MikaelElkiaer]

Sorry for the sparse description.
It does not work for rootless as it is right now, which is why I figured it was a missing feature.

I don't think it goes against the point of running as rootless.
Similarly to other extra permissions - e.g. access to a USB device or disk volume - it is still a matter of keeping permissions to a minimum and only add as needed.

[brandond]

It may seem that way, but I suspect that if you look into it you'll find its actually more complicated than that, given how the rootless namespace is isolated from the host filesystem.

Please do investigate though; if you get it working a PR would be welcome.