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Comment by iampims | Hacker News Reader

Not OP but most public cloud need stronger isolation than what Docker provides. GKE uses gVisor, AWS uses Firecracker now. When they started, lambda code was scheduled on a different EC2 instance per customer. VM isolation is just so much stronger. Firecracker hopes to make launching VMs as quick as launching containers while retaining the great isolation benefits of a VM.

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> ...GKE uses gVisor

Another commentator on this thread points out that GKE uses trimmed-down Chromium OS? https://news.ycombinator.com/item?id=25884851

Edit: I guess container-optimized Chromium OS and gVisor are complementary (that is, you're welcome to run your app in gVisor sandboxed containers on a guest VM running Google's container-optimized OS). Ref: https://go-review.googlesource.com/c/playground/+/195983

See, for instance, https://cloud.google.com/blog/products/containers-kubernetes...

Thanks. I remember mrkurt say fly.io evaluated gVisor but settled on Firecracker eventually, though, I must ask: can gVisor on its own achieve same level of protection as micro-VMs? Even if not, can the protection offered by application kernels like gVisor and Kata be considered enough for multi-tenant workloads (like the one fly.io runs) inside the same guest (VM)?

Also, if I may, in what cases would one prefer to use Firecracker managed micro-VM running gVisor sandboxed containers? I'd imagine gVisor slows things down, so it might not be for everyone, but I'm curious as to what value-add might make gVisor worth that.

That's a tough question to answer! I spent some time on it in the blog post, and a lot more time that I didn't write about hacking on little bits of gVisor while researching that post. My take is, no, I don't think gVisor is as secure as Firecracker; it's way more ambitious and has a larger attack surface. But I buy that it is substantially better than OS-sandboxed container runtimes, and I would probably trust it for multitenant workloads.

(Kata, as I understand it, is mostly about microvm containers; I like Firecracker almost as much for its implementation, which I think is pretty gorgeous, as for the microvm design choice, but I like 'em both fine I guess. Also, there's a Firecracker-based Kata that people use, right?)

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