How and why?
You're being condescending. I like Docker and if anything you make me not want to try systemd-nspawn with this attitude.
"Go on, try it" doesn't help me in any way. I believe that Docker has more attention, you might call it hype. I'd say "eyes" instead. We have here a way to shown to run everything in Docker, parent link of thread (RancherOS.) That's great, I already went ahead and tried it. I'm still waiting to be convinced that I should try nspawn instead.
Without your help, I won't even know what OS Distro I can download to try it, let alone why it's better.
I just read the ArchWiki page on systemd-nspawn[1] and I fail to see how it is any better by the way. It just looks way harder to use (Docker images vs packages, scripts and per distro instructions ; docker create, docker start, docker ps, docker logs vs pacstrap, systemd-nspawn, machinectl, journalctl) and honestly not very different technically. systemd-nspawn just looks like a less user-friendly Docker to me.
You're seeing condescension where there is none. I'm just pointing out facts. It's okay, Docker runs on hype, and apparently so do you. But then, I can't expect Red Hat to invest into advertising for a core system component, because developers ought to be aware of it.
nspawn also offers faster startup time, better integration with cgroups and chroot jails, etc.
