Re: Q: use vlan in container

[Serge Hallyn <serge.hallyn@ubuntu.com>]

Quoting Libo Chen (clbchenlibo.chen@huawei.com):
> On 2013/11/29 13:05, Serge Hallyn wrote:
> > Quoting Libo Chen (clbchenlibo.chen@huawei.com):
> >> Hello LXC experts,
> >>
> >> 	I meet a problem. When using vlan as network device in suse11 system container,
> >> I can not use halt to stop this container. It hung on "eth0 is still used from interfaces eth0" in cycle.
> >>
> >> The config file:
> >>
> >> lxc.network.type = vlan
> >> lxc.network.flags = up
> >> lxc.network.link = eth0
> >> lxc.network.name = eth0
> >> lxc.network.vlan.id = 1301
> >> lxc.network.ipv4 = 128.5.131.100/24
> >>
> >>
> >> The reason is in the shell command /sbin/ifdown, see below:
> >>
> >> ######################################################################
> >> # Shut down depending interfaces
> >> #
> >> # Check if there are interfaces which depend on this interface. If yes these
> >> # have to be shut down first.
> >> # For example these might be bonding or vlan interfaces. Note that we don't
> >> # catch all types of depending interfaces currently. See function
> >> # 'get_depending_ifaces' in file 'functions' for details.
> >> #
> >> test "$SCRIPTNAME" = ifdown && DEP_IFACES=`get_depending_ifaces $INTERFACE`
> >> if [ "$?" = 0 -a "$NODEPS" != yes ] ; then
> >>         message "`printf "    %-9s is still used from interfaces %s" \
> >>                          $INTERFACE "$DEP_IFACES"`"
> >>         for DI in $DEP_IFACES; do
> > 
> > Should the proper fix be to fix this script so that it doesn't call
> > ifdown recursively if $DI = $INTERFACE ?
> 
> Hi Serge,
> 
> yes, I had try this way before as below:
> 
>         for DI in $DEP_IFACES; do
> 	         if [ "$DI" != "$INTERFACE" ] ; then
>                        ifdown $DI -o $OPTIONS
> 	         fi
>         done
> 
> It works well, but I have no idea it is safe enough and no side effects?

It's safe enough and should have no side effects itself.  But
I recommend you first look up how get_depending_ifaces() is
implemented.  That's where this really should be fixed, and if
it turns out that the proper fix for *that* is in the kernel
then that's ok.

-serge