Firecracker MicroVMs • Hacker News Board

Re: Firecracker MicroVMs

#21

Post by hinkley » Mon, Oct 18, 2021, 8:24 PM UTC

staticassertion wrote: post #20

imachine1980_ wrote: post #14

what is the advantage of server-less if you have to have to manage the servers?

If you're hosting someone else's code.

If you work at a large enough company it all starts to look like someone else’s code.

The malicious person can always find the worst way to break everything, but dumb luck can get you pretty close.

Re: Firecracker MicroVMs

#22

Post by mikepurvis » Mon, Oct 18, 2021, 8:32 PM UTC

lgierth wrote: post #18

staticassertion wrote: post #2

For those using firecracker, what's your method for building a rootfs?

I build them using Buildah, then mkfs.ext4, mount, cp, umount. It's a little bit annoying that I'm still using root at least for the mount part. OpenWrt's build system has a method of building rootfs ext4 and squashfs images without any root, it's somewhere in that large Makefile mess. (sorry, reposting this as I first replied to the wrong parent)

I similarly have built bootable disk images with various tools including buildah and have never been able to fully get away from needing root for various chrooty/loopbacky parts of the process. In principle, it should be very possible to point grub at a filesystem-in-a-file and be like "install to that", but I could never make it happen; it always wanted to be trying to infer things about how to configure itself from examining the host system.

And yes, I've studied the OpenWRT build to no avail. I would be delighted for someone to dissect whatever it is that goes on in there and write it up.

Re: Firecracker MicroVMs

#23

Post by gnufx » Mon, Oct 18, 2021, 8:48 PM UTC

paxys wrote: post #8

Does anyone know of any good orchestrators for Firecracker VMs? While the technology is great, the CLI and API are still a bit too complex and low-level to implement some basic use cases in production.

Depending on what you want, OpenNebula (opennebula.io) has been making a thing of Firecracker.

Re: Firecracker MicroVMs

#24

Post by bminor13 » Mon, Oct 18, 2021, 8:50 PM UTC

lgierth wrote: post #18

staticassertion wrote: post #2

For those using firecracker, what's your method for building a rootfs?

I build them using Buildah, then mkfs.ext4, mount, cp, umount. It's a little bit annoying that I'm still using root at least for the mount part. OpenWrt's build system has a method of building rootfs ext4 and squashfs images without any root, it's somewhere in that large Makefile mess. (sorry, reposting this as I first replied to the wrong parent)

No experience with Firecracker specifically, but if squashfs images are sufficient, one should be able to build a tar archive of the filesystem without root (where all the files have the correct owners, mode, etc.) and then convert it to squashfs using `tar2sqfs` in https://github.com/AgentD/squashfs-tools-ng, also without root - I've done something like this to create squashfs images in constrained build environments, which worked well.

Re: Firecracker MicroVMs

#25

Post by adolph » Mon, Oct 18, 2021, 9:07 PM UTC

badLiveware wrote: post #9

paxys wrote: post #8

Does anyone know of any good orchestrators for Firecracker VMs? While the technology is great, the CLI and API are still a bit too complex and low-level to implement some basic use cases in production.

Kubernetes using Kata containers[1] as a containerd[2] backend [1] https://aws.amazon.com/blogs/opensource/kata-containers-1-5-... [2] https://github.com/kata-containers/kata-containers/blob/main...

How does that compare to firecracker-containerd?

https://github.com/firecracker-microvm/firecracker-container...

This repository enables the use of a container runtime, containerd, to manage Firecracker microVMs. Like traditional containers, Firecracker microVMs offer fast start-up and shut-down and minimal overhead. Unlike traditional containers, however, they can provide an additional layer of isolation via the KVM hypervisor.

Re: Firecracker MicroVMs

#26

Post by wmf » Mon, Oct 18, 2021, 9:09 PM UTC

m00dy wrote: post #5

anyone knows this can create gpu-enabled microvms ?

Maybe try Cloud Hypervisor instead. https://www.phoronix.com/scan.php?page=news_item&px=Cloud-Hy...

Re: Firecracker MicroVMs

#27

Post by gizdan » Mon, Oct 18, 2021, 9:09 PM UTC

Anyone any thought on using this in a homelab (just random servers such as laptops and microservers) with K8s vs normal containers?

Re: Firecracker MicroVMs

#28

Post by tough » Mon, Oct 18, 2021, 9:20 PM UTC

I bookmarked this about firecracker's internals in HN in the past https://www.talhoffman.com/2021/07/18/firecracker-internals/

Re: Firecracker MicroVMs

#29

Post by andrewstuart » Mon, Oct 18, 2021, 9:24 PM UTC

Note that this Amazon developed technology does not work on Amazon Web Services instances.

It does however work on Google, Azure and Digital Ocean instances where you can configure nested virtualisation.

Re: Firecracker MicroVMs

#30

Post by cptnntsoobv » Mon, Oct 18, 2021, 9:36 PM UTC

andrewstuart wrote: post #29

Note that this Amazon developed technology does not work on Amazon Web Services instances. It does however work on Google, Azure and Digital Ocean instances where you can configure nested virtualisation.

It works on AWS's metal instances, doesn't it?

That is definitely a constraint though, as the smallest available metal instances are pretty large, hence costly on a per instance basis.