Docker has always used microVMs (well since 2016)

cr125rider

Is all of docker one “micro” VM though? Or does each container get a clean, fresh one?

sudb

One reason I think a distinction is made is that native Docker-in-Docker can be a real pain, but Docker in a Firecracker microVM "just works".

yjftsjthsd-h

> What if I told you that Docker Desktop has always used microVMs? Then I would say your title is wildly misleading.

unsnap_biceps

Article title is a bit click-baity. The article is only talking about Docker Desktop on Mac or Windows. Docker Linux have not been using microVMs for a decade.

rvz

...*on macOS only and runs qemu as the emulator. We know. But of course the hype of "microVMs" is just a rebranding of existing technologies with some modifications, macOS needed extra virtualization technologies just for containers for years: Docker Desktop macOS (until 2025): QEMU + Virtualization.framework + Linux kernel (without extra drivers) = "microVM". Now they use the native Apple virtualization libraries instead of QEMU for both containers and microVMs. [0] Linux never needed to use KVM for containers, but requires it for microVMs: Linux: KVM + Linux kernel (without extra drivers) = Firecracker "microVM". In reality, it is different depending on the OS that you are using. [0] https://www.docker.com/blog/docker-desktop-for-mac-qemu-virt...

garypdx

Yawn. IBM/AIX's WPARs & LPARs, Sun/Solaris' dynamic system domains & zones, BSD jails. How many times are we going to pat ourselves on the back for reinventing the wheel?

kj4ips

I often wonder what would have happened if rkt had been more successful.

Betelbuddy

Its bending history to call what before were Linux Vms inside Mac or Windows to have containers to that is a real MicroVM. And the current Sandboxes dont offer the same security model - See Docker Sandboxes 0.42.0 security update: CVE-2026-77179 and CVE-2026-79994 https://docs.docker.com/security/security-announcements/

davoneus

I wonder if this is due to Microsoft pushing forward with wslc in the past week or so. I tried pure wslc for a project or two this past week. It got me 90% of the way but not all the way. Still pretty impressive, even if it is another example of extend and extinguish.

screm

And yet it's never picked by coding agents for sandboxes -> https://armature.tech/leaderboards#app/sandboxes

segmondy

I was just exploring the new docker sandbox and saw that they could retain all your data in/out of the sandbox for 30 days. I wash my hand of docker, use with care. Data is gold and lots of companies are now going to be giving their "free" products as a sort of trojan horse to steal your data.

otterley

Docker *Desktop*, not Docker Engine. Most uses of Docker, at least until Kubernetes shifted to containerd, were the latter. The reality is that most running production containers today share a kernel.

jeswin

Dynamic memory hot-plugging is still not as efficient. So if you don't want strict isolation between containers or individual sandboxes around each one of them, avoid VMs to achieve the highest density per box.