[lxc-devel] [PATCH v2 1/2] Add option to lxc-attach to select specific namespaces

[Daniel Lezcano]

On 05/22/2012 05:58 PM, Christian Seiler wrote:
> Hi Serge,
>
>>>>> What about if we update the command interface to add an additional
>>>>> command along the lines of LXC_COMMAND_GET_NSFLAGS or similar,
>>> which
>>>>> returns the bitmask of CLONE_* used for starting the container?
>>> Then
>>>>> we would have the logic:
>>>>
>>>> That works fine for persistent containers which were started
>>> without
>>>> any command line changes.  But even with a persistent container
>>> with
>>>> no network section, I could add a network section on the lxc-start
>>>> command line with '-s' arguments, making the set of cloned
>>> namespaces
>>>> different from what you'd expect from the config file.  So there is
>>>> no good way I can think of, generally, to get that bitmask of
>>> CLONE_*
>>>> flags used for starting the container.
>>>
>>> You misunderstood me: I don't want to read the configuration file -
>>> I
>>> want to ask the still-running lxc-start process (that listens on the
>>> abstract socket for the container) to give me the flags it used when
>>> it was run. Just as it may be asked to return a file descriptor for
>>> the console or the PID of the init process. We don't have to
>>> generate
>>> any file or store anything, we can just keep the information in a
>>> simple variable that we return via the command interface in case
>>> lxc-attach (or somebody else) asks.
>>
>> That sounds good :)

Yep, +1.

   -- Daniel