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

[Christian Seiler]

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 :)

Ok, then I'll update the patches and resend them to the list.

Regards,
Christian