Re: [PATCH] sys-tools: Add setns utility to sys-tools

[Karel Zak <kzak@redhat.com>]

On Wed, Dec 19, 2012 at 02:06:46PM -0500, Neil Horman wrote:
> Like the unshare command, which lets a user from the command line detach from
> specific namespaces of the parent process, and execute a command, setns provides
> a frontend to the setns(2) syscall, which allows a user to migrate a process to
> the namespaces of other processes, prior to calling exec on a command.

Do we really need a new command? Can't we extend unshare(1)?

 create a new namespace:

    unshare --{mount,ipc,...} <program> [<args>]
    
 move to already existing namespace:

    unshare --namespace <pid> --{ipc,...} <program> [<args>]


>From user's point of view in both cases the <program> will be unshared
from the current namespace so the util name seems OK.

IMHO it seems better then add a new command.


If you really want to support direct namespace paths (/proc/<pid>/ns/<nsname>)
then we can use

    unshare --namespace <path> <program> [<args>]

anyway this way should be optional and not required. It's naive to
expect that everyone remembers and understands all the /proc tricks.

    Karel

-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com