On Running systemd-nspawn Containers (2022)

#1

Post by cautious-fly » Fri, Feb 21, 2025, 8:00 AM UTC

On Running systemd-nspawn Containers (2022)
benjamintoll.com

Re: On Running systemd-nspawn Containers (2022)

#2

Post by nesarkvechnep » Fri, Feb 21, 2025, 9:06 AM UTC

systemd-nspawn is great! It's well integrated with the init system, works as expected.

Re: On Running systemd-nspawn Containers (2022)

#3

Post by letters90 » Fri, Feb 21, 2025, 9:14 AM UTC

I used nspawn to get a system running in the most ridiculous way.

A debian aarch64 vm on kvm starting a systemd-nspawn for an unpacked raspberry pi 3 iso.

It works way too well judging by how ridiculous it was.

Still saved me a few days instead of setting things up myself.

I actually liked how easy it is to spin up nspawn as a systemd service

  [Unit]
  Description=Raspberry Image Machine
  After=multi-user.target

  [Service]
  Type=simple
  User=root

  ExecStart=/usr/bin/systemd-nspawn -D /mnt/ /sbin/init

  [Install]
  WantedBy=multi-user.target

Re: On Running systemd-nspawn Containers (2022)

#4

Post by Imustaskforhelp » Fri, Feb 21, 2025, 9:31 AM UTC

letters90 wrote: post #3

I used nspawn to get a system running in the most ridiculous way. A debian aarch64 vm on kvm starting a systemd-nspawn for an unpacked raspberry pi 3 iso. It works way too well judging by how ridiculous it was. Still saved me a few days instead of setting things up myself. I actually liked how easy it is to spin up nspawn as a systemd service [Unit] Description=Raspberry Image Machine After=multi-user.target [Service…

hmm this is very interesting.

I am wondering though? Is there something like systemd-nspawn that doesn't require root?

Re: On Running systemd-nspawn Containers (2022)

#5

Post by i_v » Fri, Feb 21, 2025, 9:36 AM UTC

letters90 wrote: post #3

I used nspawn to get a system running in the most ridiculous way. A debian aarch64 vm on kvm starting a systemd-nspawn for an unpacked raspberry pi 3 iso. It works way too well judging by how ridiculous it was. Still saved me a few days instead of setting things up myself. I actually liked how easy it is to spin up nspawn as a systemd service [Unit] Description=Raspberry Image Machine After=multi-user.target [Service…

I used to use qemu-user-static to run ARM Linux distros like Buildroot, Yocto, and Raspbian on x88_64. It worked surprisingly well! Outside of some minor bugs here and there, it was perfect for local development, emulating an embedded system I was working on.

Re: On Running systemd-nspawn Containers (2022)

#6

Post by derobert » Fri, Feb 21, 2025, 9:44 AM UTC

Imustaskforhelp wrote: post #4

letters90 wrote: post #3

I used nspawn to get a system running in the most ridiculous way. A debian aarch64 vm on kvm starting a systemd-nspawn for an unpacked raspberry pi 3 iso. It works way too well judging by how ridiculous it was. Still saved me a few days instead of setting things up myself. I actually liked how easy it is to spin up nspawn as a systemd service [Unit] Description=Raspberry Image Machine After=multi-user.target [Service…

hmm this is very interesting. I am wondering though? Is there something like systemd-nspawn that doesn't require root?

It looks like systemd-nspawn is gaining rootless support, see https://github.com/systemd/systemd/issues/30239

Until then, I'm not sure if there is anything lightweight. If you don't need lightweight, there is Podman.

Re: On Running systemd-nspawn Containers (2022)

#7

Post by egorfine » Fri, Feb 21, 2025, 9:45 AM UTC

On an unrelated note, is there a way to share some negative feedback on systemd projects without incurring significant hit to karma?

Re: On Running systemd-nspawn Containers (2022)

#8

Post by trurl42 » Fri, Feb 21, 2025, 9:47 AM UTC

> Unfortunately, though, most developers don’t even know that there are options outside of Docker, or that they’re not as “convenient”.

> Hopefully, this article has disabused some of that notion.

If that was the goal, it seems terribly complicated when compared with podman.

Re: On Running systemd-nspawn Containers (2022)

#9

Post by proxysna » Fri, Feb 21, 2025, 9:48 AM UTC

Used nomad in my homelab to run nspawn containers with nspawn driver[1]

Surprisingly simple and low footprint solution and genuinely pleasant to work with, since it is very similiar to managing a Systemd service.

[1]https://github.com/JanMa/nomad-driver-nspawn

Re: On Running systemd-nspawn Containers (2022)

#10

Post by vaylian » Fri, Feb 21, 2025, 9:55 AM UTC

letters90 wrote: post #3

I used nspawn to get a system running in the most ridiculous way. A debian aarch64 vm on kvm starting a systemd-nspawn for an unpacked raspberry pi 3 iso. It works way too well judging by how ridiculous it was. Still saved me a few days instead of setting things up myself. I actually liked how easy it is to spin up nspawn as a systemd service [Unit] Description=Raspberry Image Machine After=multi-user.target [Service…

You might want to look into .nspawn files instead. Then you can also manage your nspawn-containers with the machinectl command.

See man 5 systemd.nspawn

And many command like systemctl and journalctl accept the -M parameter, which allows you to query systemd units inside your nspawn-containers from the host.

edit: The article actually explains all of these things in more detail.