Dran

You’re correct that nesting namespaces is unlikely to introduce measurable performance degradation. For performance, I was thinking mostly in the nested virtual network stack adding latency. Both docker and lxc run their own virtual interfaces.

There’s also the issue of running nested apparmor, selinux, and/or seccomp checks on processes in the child containers. I know that single instances of those are often enough to kill performance on highly latency sensitive applications (SAP netweaver is the example that comes to mind) so I would imagine two instances of those checks would exacerbate those concerns.

There are security performance and capability concerns with that approach, apparmor on the first layer lxc probably being the most annoying.

If you want to isolate your docker sandbox from your main host, you should use a vm not a container.

This is the way