Bottlerocket runs containers using containerd, so containers are visible as processes on the host, from its perspective, not currently isolated from each other via a hypervisor. Bottlerocket limits containers ability to interact with the host or each other via SELinux, among other things.

We do have firecracker-containerd (https://github.com/firecracker-microvm/firecracker-container...) which is designed to allow the containerd runtime to launch containers as microVMs via Firecracker, with that additional layer of isolation via the KVM hypervisor. This stack is not currently fully compatible with K8s or ECS though, so it is not implemented using that approach yet. Rather Bottlerocket is built as a progressive improvement on the current state of container hosts, which is that many people are running all their containers on their hosts without any strong security hardening at all.

I think from the similar naming scheme of Firecracker and Bottlerocket you can already see the pieces of the puzzle that are in progress and the future potential though.

Thanks, I was more wondering what the relationship was between something like Debian GNU/linux and bottlerocket. From gp description it sounds like there's no "GNU userland", just the Linux kernel and some utility functions in rust - enough to launch containerd.

So if I have a heterogeneous collection of servers - I could install Debian, and run docker on Debian. It sounds like bottlerocket would more comfortably run on top of a hypervisor abstracting away the actual hw a bit? Eg on top of xen, kvm or VMware?

Obviously the Linux kernel can be made to run on a toaster, but maybe bottlerocket isn't ideal for that purpose?

Answering your initial question and this one: Bottlerocket today only runs in EC2, but we've tried to make it flexible enough to run outside of a hypervisor on bare metal in the future (in fact, a few engineers on the team are really excited to get it running on their RaspberryPi's at home; toasters haven't been added to our roadmap yet ;) ).

Bottlerocket has a GNU userland like many other distros. It is just one that is stripped down of many things including removal of interpreters, shells, and package managers.

If you want to explore more deeply, you can enable the admin container and jump into a shell on the host[1] to look at the filesystem and see what Bottlerocket's userspace looks like up close and personal. You can also see a bit more of this debugging/exploration tooling explained in an AWS Partner Blog[2].

[1] https://github.com/bottlerocket-os/bottlerocket#admin-contai... [2] https://aws.amazon.com/blogs/apn/getting-started-with-bottle...