The zombie reaping problem is fixed in Docker. You can simply use `docker run --init` with no argument, and it will spawn a tiny init that will reap children processes correctly. We don't enable the flag by default to respect backwards compatibility.

Sidenote: this Docker native implementation uses Tini (https://github.com/krallin/tini#using-tini)

Could you explain a bit further?

What does backwards compatibility mean in this context. The API?

In this context it means preserving the default behavior of running the command specified in the image as PID 1, and not injecting any extra processes in the namespace. The difference in the runtime environment is subtle, but some applications rely on it. If we changed this default those applications would behave differently after upgrading to Docker 1.13 or later.

This would require Kubernetes to do the same, which I don't think it does?

It's up to the Kubernetes developers to decide if they want to use that feature of Docker, yes.

I believe shared pid namespaces are landing in kubernetes 1.7.0 and therefore should be available relatively soon, no?

Not sure. The changelog doesn't include PID namespaces yet, not sure if it will be merged: https://github.com/kubernetes/kubernetes/blob/master/CHANGEL...

It's in there, under "Changelog since v1.7.0-alpha.3"

Oops, I was on mobile and didn't see that the list wasn't linear with respect to version numbers. That's awesome.

I hope GKE is planning to migrate to a newer Docker version soon (they've been on 1.11.2 for a long time) so we can benefit from this.

The zombie problem is solved by reaping children?

I guess Craster was right after all.

:)