The chroot Technique – a Swiss army multitool for Linux systems • Hacker News Board

Re: The chroot Technique – a Swiss army multitool for Linux systems

#11

Post by mystified5016 » Wed, Apr 09, 2025, 2:55 PM UTC

smallpipe wrote: post #2

The arch linux install has a little wrapper around chroot, used to configure the installed system without booting it. https://wiki.archlinux.org/title/Installation_guide#Chroot

Manjaro has the same, I'd assume inherited from arch and modified.

I just wish the script could figure out a BTRFS drive without me manually mounting volumes :(

Re: The chroot Technique – a Swiss army multitool for Linux systems

#12

Post by bigpeopleareold » Wed, Apr 09, 2025, 2:55 PM UTC

Ah - my attempt at doing this was almost there, except for the few bits that kept erroring out because I didn't mount the proc,dev,etc. mountpoints correctly :) Something to give another whirl on. At the time, I wanted something simple without docker to store everything development-related using different libraries. This is where debootstrap+chroot comes in - to build against various versions of libraries in Debian (if I remember correctly - it's been awhile.)

Re: The chroot Technique – a Swiss army multitool for Linux systems

#13

Post by SuperNinKenDo » Wed, Apr 09, 2025, 2:56 PM UTC

dicroce wrote: post #4

I actually wish that instead of docker & etc we had just gotten a better chroot... Or maybe just a new kernel syscall that is chroot()++.

systemd-nspawn is probably what you want.

Re: The chroot Technique – a Swiss army multitool for Linux systems

#14

Post by a_t48 » Wed, Apr 09, 2025, 2:57 PM UTC

Currently working on scripts to provision a drive outside of the machine it’s meant to go on using chroot. I’ve so far accidentally unmounted /dev/pts several times from the host system and running docker inside the chroot caused a hard lock. Fun stuff.

Re: The chroot Technique – a Swiss army multitool for Linux systems

#15

Post by duped » Wed, Apr 09, 2025, 2:58 PM UTC

dicroce wrote: post #4

I actually wish that instead of docker & etc we had just gotten a better chroot... Or maybe just a new kernel syscall that is chroot()++.

what would "better chroot" do?

Re: The chroot Technique – a Swiss army multitool for Linux systems

#16

Post by miftassirri » Wed, Apr 09, 2025, 2:59 PM UTC

Haha, learned this technique while installing Void Linux

Re: The chroot Technique – a Swiss army multitool for Linux systems

#17

Post by ddoolin » Wed, Apr 09, 2025, 3:03 PM UTC

Chroot has saved my system more times than I care to admit. I didn't really understand how it worked though, interesting.

Re: The chroot Technique – a Swiss army multitool for Linux systems

#18

Post by andreareina » Wed, Apr 09, 2025, 3:05 PM UTC

This is how Linux From Scratch is done, and I've used the same technique to install missing video drivers that the Ubuntu install didn't include for whatever reason.

Re: The chroot Technique – a Swiss army multitool for Linux systems

#19

Post by zokier » Wed, Apr 09, 2025, 3:08 PM UTC

Sure, chroot can be useful in a pinch, but it would not be the first thing I'd reach to. If you got the partitions mounted, you can already do quite a lot of things without needing to chroot.

Re: The chroot Technique – a Swiss army multitool for Linux systems

#20

Post by paulddraper » Wed, Apr 09, 2025, 3:13 PM UTC

dicroce wrote: post #4

I actually wish that instead of docker & etc we had just gotten a better chroot... Or maybe just a new kernel syscall that is chroot()++.

Apples and oranges.

Among many other things, Docker (and Podman etc) has

1. Images and OverlayFS

2. Networking

3. User namespace mappings

4. Resource management

---

If all you want is file system isolation, then docker (and postman, etc) is massive overkill chroot is correct.