Show HN: NSL – WSL for Linux

Show HN: NSL – WSL for Linux(frostyard.github.io)

43 points by bketelsen 3 hours ago | 32 comments

One of the things that Windows really got right is WSL2. I drive an atomic Linux distro for daily use, but wanted a way to develop with multiple different distros with that same WSL UX. NSL is my answer. It is a faithful reproduction of the developer experience, powered by a single VM that hosts one or more systemd-nspawn containers with your development instances. Host file edits and port sharing come along for the ride, just like WSL. Take a look and tell me what you think... It's yet another step in my long journey to keep my host installation free from all the changing and breaking dev dependencies that force a reinstall every few months.

rao-v 1 hour ago |

I have to say this is nice packaging. It is weirdly not obvious how nice it is to cleanly use a different “machine” inside your desktop.

I never thought I’d prefer WSL to even my MacBook for working with remote servers and dev but somehow I do.

I of course know the many ways to roll something like this for myself, yes dev containers are better for many things etc. but it’s wierd how good the ergonomics of a WSL like container are.

bketelsen 52 minutes ago | |

Thanks for saying so! That's exactly why I wrote this. The UX of wsl2 is just right. There are a lot of other ways to accomplish this, but none touch that same experience.

0x457 1 hour ago |

I'm confused why VM + systemd-nspawn? From my understaing WSL 2 runs a single VM + something like systemd-nspawn per "linux installation", but it runs a VM because it needs linux kernel. Why not just do systemd-nspawn if you alread on linux?

pkulak 41 minutes ago | |

Way better isolation, is my guess. Plus, you can use a different kernel this way.

I used to poo-poo when people said that containers aren't a _real_ security boundary, at least for personal stuff, and not a multi-tenant server. But I bet even mid-tier LLMs can break out of LXC/Docker/nspawn at this point.

fhn 6 minutes ago | | |

can they not break out of a VM?

bketelsen 54 minutes ago | |

you could, and if that's your preference https://nspawn.org is just right.

0x457 50 minutes ago | | |

Neat, I wasn't aware of this tool. I just either run nixosContainer in systemd-nspawn or OCI image in systemd-nspawn.

delusional 58 minutes ago | |

Claude told him to do it this way.

nateb2022 46 minutes ago | | |

I'd trust OP to make good architectural decisions/provide guidance even if AI mostly wrote the docs and UI. Looking into their GitHub, seems they are an engineering manager at Microsoft and contribute semi regularly to uBlue and Project Bluefin. Should be better quality than some random vibeslopper.

michaelastreiko 10 minutes ago |

Nice flip of the WSL idea the other way — simple interop like this keeps a one-person stack from turning into a VM zoo.

bee_rider 16 minutes ago |

The name WSL has always struck me as a bit back area (LSW would seem to make more sense, since it is a Linux subsystem for Windows). I guess they mean it as a Windows Subsystem for Linuxing.

Anyway, should this be called LSL or WSLL? Or maybe LSWSL.

thayne 1 hour ago |

How does this compare to distrobox?

bketelsen 1 hour ago | |

Distrobox mounts $HOME in the container at $HOME by default. WSL and NSL do not, and that's my preference. This means you can install tools that change your default path, change your dotfiles, etc, without affecting the host. The other obvious difference is that distrobox is powered by podman or docker, while NSL uses a VM that runs systemd-nspawn containers.

rpcope1 1 hour ago |

So you've just basically reimplemented LXC?

pkulak 1 hour ago | |

Nope. This is a VM, with containers inside. And the containers weren't "re-implemented", it uses existing systemd containers. That's what I was able to learn by skimming the site for 30 seconds. Did you not even do that? And why even be so condescending to someone else's project?

ktm5j 1 hour ago | | |

Because it does seem like we already have tools that skin this particular cat, it's valid to wonder what value this project provides over existing solutions.. even if they chose the wrong example to compare it to. Why do you think that's condescending?

nurettin 53 minutes ago | | |

LXC is a jail and qemu is an extra layer of emulation. Why pay that extra cost? Just because it serves a wsl image isn't really an answer. How is that worth the extra layer?

graemep 1 hour ago |

This is most useful to people who run Linux as their daily driver so rather than saying its like WSL can you explain what it offers that existing Linux containers do not?

Its also sounds different from WSL which I thought is a VM rather than a container.

> It's yet another step in my long journey to keep my host installation free from all the changing and breaking dev dependencies that force a reinstall every few months.

Something that also require a bit of explanation. What do you do that makes this such a common problem.

bketelsen 1 hour ago | |

WSL2 uses a shared VM that does host integration (networking, shared files, permanent storage for each instance). NSL uses the same model but with Linux native technical implementations.

As for keeping my host clean - it's the developer's curse that always gets me. Install libWhatever3.2-dev because you need it to compile something, then don't realize until next time you open Chrome that it broke your system in some subtle way. There are dozens of ways to solve this like devcontainers, docker, incus, fully separate or remote vms. I like the WSL2 model so I wanted that same UX.

dingaling911 1 hour ago |

Looks very cool.

Now all you have to do is run NSL under WSL.

bketelsen 1 hour ago | |

challenge accepted!

RandomGerm4n 1 hour ago |

There's already Distrobox, which does exactly the same thing but isn't slop.

KyleGospo 36 minutes ago | |

This handles use cases Distrobox can't, they both have a place.

varispeed 1 hour ago |

The project is cool, but please use human written text.

The website's Claudisms are unbearable.

the_real_cher 1 hour ago |

IS it LXC containers or docker? Or are you running a custom chroot namespace setup?

bketelsen 1 hour ago | |

none of the above. a single vm started by systemd-vmspawn which then starts one or more containers for your instances using systemd-nspawn. It ends up being fast and lightweight.

mhitza 1 hour ago | |

Haven't checked the actual project but he does state he uses systemd-nspawn. Which is it's own kind of container runtime.

smw 1 hour ago | |

He runs a systemd-nspawnd container in a "small vm", so neither really?