On: Docker 0.9: introducing execution drivers and libc...

[philips]

There is a tool called nsenter which is part of util-linux which can be used to enter the namespace of another PID. You can find the manpage here: http://man7.org/linux/man-pages/man1/nsenter.1.html

This can be used for docker, lxc, libvirt-lxc or nspawn.

[FooBarWidget → philips]

That only works for the Docker backends that are based on Linux namespaces. What about backends like OpenVZ or FreeBSD jails? Even if I limit the scope to Linux namespaces, for arbitrary shell commands to work properly, I have to know exactly which namespaces Docker use, which may be version-specific or configuration-specific.