[lxc-devel] [PATCH] Add option to lxc-attach to select specific namespaces

[Christian Seiler]

>> +	int flags[] = { CLONE_NEWPID, CLONE_NEWNS, CLONE_NEWNET, CLONE_NEWIPC, CLONE_NEWUTS };
> ...
>> -static char *namespaces_list[] = {
>> -	"MOUNT", "PID", "UTSNAME", "IPC",
>> -	"USER", "NETWORK"
>> -};
>> -static int cloneflags_list[] = {
>> -	CLONE_NEWNS, CLONE_NEWPID, CLONE_NEWUTS, CLONE_NEWIPC,
>> -	CLONE_NEWUSER, CLONE_NEWNET
>> -};
> 
> These should be commonized.  I'm surprised this patch worked for you, as
> the indices for network don't match up.

Yes, they do, but you have to see which one matches against which:

namespaces_list <-> cloneflags_list

but in the lxc_attach_to_pid there's

char *ns[] = { "pid", "mnt", "net", "ipc", "uts" };

so we have

flags <-> ns. In the end, those are totally different arrays.

I've blacklisten USER because I don't know to which file in
/proc/$pid/ns it will map to once the feature is inside the kernel (I
only see the 5 in the char *ns[] list on my system) - I'll happily
rearrange them and add CLONE_NEWUSER to the flags and ns lists in the
attach to pid function.

Regards,
Christian