LXC with Open vSwitch

Question

I want to try OVS (software Linux switch) http://openvswitch.org/ with my LXC container with Ubuntu as host and guest. So I have installed it:

# apt-get install openvswitch-switch

Configured according this doc https://infologs.wordpress.com/2015/06/19/how-to-attach-lxc-container-to-ovs-openvswitch/

Created test container:

# lxc-create -t ubuntu -n veth03-ovs -- -r trusty

Created ovs bridge and assigned IP to it:

# ovs-vsctl add-br switch0
# ip add add 192.168.100.1/24 dev switch0

Let it be new network 192.168.100.0/24 and switch0 (according to my understanding) will be first address (gateway) there.

Looks fine:

# ip a
...
4: ovs-system: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default 
    link/ether 52:9d:e1:60:1d:56 brd ff:ff:ff:ff:ff:ff
5: switch0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default 
    link/ether 16:63:eb:47:13:41 brd ff:ff:ff:ff:ff:ff
    inet 192.168.100.1/24 scope global switch0
       valid_lft forever preferred_lft forever

Bridge interface status:

# ovs-vsctl show
1b236728-4637-42a5-8b81-53d4c93a6803
    Bridge "switch0"
        Port "switch0"
            Interface "switch0"
                type: internal
    ovs_version: "2.3.2"

Edited LXC config for veth03-ovs container for using this bridge:

# vim /var/lib/lxc/veth03-ovs/config
...
lxc.network.type = veth
lxc.network.flags = up

lxc.network.script.up = /etc/lxc/ifup
lxc.network.script.down = /etc/lxc/ifdown
# lxc.network.veth.pair = lxc0
lxc.network.hwaddr = 00:16:3e:15:b3:62
lxc.network.ipv4 = 192.168.100.10

So I want to point 192.168.100.10 for internal interface of container.

/etc/lxc/ifup and /etc/lxc/ifdown add/remove ports for this bridge after start/stop of container.

# cat /etc/lxc/ifup
#!/bin/bash

BRIDGE=”switch0″
ovs-vsctl –may-exist add-br $BRIDGE
ovs-vsctl –if-exists del-port $BRIDGE $5
ovs-vsctl –may-exist add-port $BRIDGE $5

# cat /etc/lxc/ifdown 
#!/bin/bash
ovsBr=’switch0′
ovs-vsctl –if-exists del-port ${ovsBr} $5

So now I want to start container but getting:

# lxc-start -n veth03-ovs --logfile /tmp/log
lxc-start: lxc_start.c: main: 344 The container failed to start.
lxc-start: lxc_start.c: main: 346 To get more details, run the container in foreground mode.
lxc-start: lxc_start.c: main: 348 Additional information can be obtained by setting the --logfile and --logpriority options.

# cat /tmp/log
  lxc-start 1448974395.199 ERROR    lxc_conf - conf.c:run_buffer:342 - Script exited with status 1
  lxc-start 1448974395.225 ERROR    lxc_conf - conf.c:lxc_create_network:3079 - failed to create netdev
  lxc-start 1448974395.225 ERROR    lxc_start - start.c:lxc_spawn:950 - failed to create the network
  lxc-start 1448974395.225 ERROR    lxc_start - start.c:__lxc_start:1213 - failed to spawn 'veth03-ovs'
  lxc-start 1448974400.730 ERROR    lxc_start_ui - lxc_start.c:main:344 - The container failed to start.
  lxc-start 1448974400.730 ERROR    lxc_start_ui - lxc_start.c:main:346 - To get more details, run the container in foreground mode.
  lxc-start 1448974400.730 ERROR    lxc_start_ui - lxc_start.c:main:348 - Additional information can be obtained by setting the --logfile and --logpriority options.

I suppose that error in lxc.network.script.up / lxc.network.script.down scripts and its are not getting $5 parameter, which should be intermediate interface passed by LXC to OVS. But I am not sure.

Is LXC supports Open vSwitch? https://github.com/lxc/lxc/issues/256

ipeacocks ipeacocks · Accepted Answer · 2015-12-02T09:16:52

It was my bad. I've just copied ifup/ifdown scripts from Wordpress blog. But there were typos:

ovs-vsctl –may-exist add-br $BRIDGE

but should be:

ovs-vsctl --may-exist add-br $BRIDGE

--, not just - before may. The same everywhere in ifup/ifdown scripts. So they should look as these:

# cat /etc/lxc/ifup
#!/bin/bash

BRIDGE=switch0
ovs-vsctl --may-exist add-br $BRIDGE
ovs-vsctl --if-exists del-port $BRIDGE $5
ovs-vsctl --may-exist add-port $BRIDGE $5

# cat /etc/lxc/ifdown
#!/bin/bash
ovsBr=switch0
ovs-vsctl --if-exists del-port ${ovsBr} $5

LXC with Open vSwitch

1 Answers