ustcweizhou 3729511c37 kvm: Fix three issues with Ubuntu 16.04 hosts (#3227)
* ubuntu16: fix unable to add host if cloudbrX is not configured

while add a ubuntu16.04 host with native eth0 (cloudbrX is not configured),
the operation failed and I got the following error in /var/log/cloudstack/agent/setup.log

```
DEBUG:root:execute:ifconfig eth0
DEBUG:root:[Errno 2] No such file or directory
  File "/usr/lib/python2.7/dist-packages/cloudutils/serviceConfig.py", line 38, in configration
    result = self.config()
  File "/usr/lib/python2.7/dist-packages/cloudutils/serviceConfig.py", line 211, in config
    super(networkConfigUbuntu, self).cfgNetwork()
  File "/usr/lib/python2.7/dist-packages/cloudutils/serviceConfig.py", line 108, in cfgNetwork
    device = self.netcfg.getDefaultNetwork()
  File "/usr/lib/python2.7/dist-packages/cloudutils/networkConfig.py", line 53, in getDefaultNetwork
    pdi = networkConfig.getDevInfo(dev)
  File "/usr/lib/python2.7/dist-packages/cloudutils/networkConfig.py", line 157, in getDevInfo
    elif networkConfig.isBridge(dev) or networkConfig.isOvsBridge(dev):
```

The issue is caused by commit 9c7cd8c2485412bc847b2c2473b962fa01435b24
2017-09-19 16:45 Sigert Goeminne ● CLOUDSTACK-10081: CloudUtils getDevInfo function will now return "bridge" instead o

* ubuntu16: Stop service libvirt-bin.socket while add a host

service libvirt-bin.socket will be started when add a ubuntu 16.04 host
DEBUG:root:execute:sudo /usr/sbin/service libvirt-bin start

However, libvirt-bin service will be broken by it after restarting
Stopping service libvirt-bin.socket will fix the issue.

An example is given as below.

```
root@node32:~# /etc/init.d/libvirt-bin restart
[ ok ] Restarting libvirt-bin (via systemctl): libvirt-bin.service.
root@node32:~# virsh list
error: failed to connect to the hypervisor
error: no valid connection
error: Failed to connect socket to '/var/run/libvirt/libvirt-sock': No such file or directory

root@node32:~# systemctl stop libvirt-bin.socket

root@node32:~# /etc/init.d/libvirt-bin restart
[ ok ] Restarting libvirt-bin (via systemctl): libvirt-bin.service.
root@node32:~# virsh list
 Id    Name                           State
----------------------------------------------------

```

* ubuntu16: Diable libvirt default network

By default, libvirt will create default network virbr0 on kvm hypervisors.
If vm uses the same ip range 192.168.122.0/24, there will be some issues.

In some cases, if we run tcpdump inside vm, we will see the ip of kvm hypervisor as source ip.
2019-05-05 13:57:58 +05:30
..