[Kimchi-devel] [PATCH V3 3/3] Issue #302: let 'create' attr of networks model to create default network

[shaohef at linux.vnet.ibm.com]

From: ShaoHe Feng <shaohef at linux.vnet.ibm.com>

Then the IP and Bridge name will not be hard coded.

Also in some scenarios, such as in nested KVM, the default network
created by kimchi on L2 guest can avoid the same network address of
L2.

https://github.com/kimchi-project/kimchi/issues/302

Test this patch:
1. change the IP address of default network to the subnet that one
of your host interface is in.
$ sudo virsh  net-destroy default
$ sudo virsh  net-edit default

2. restart kimchi.

3. check the ip address changes.
$ sudo virsh  net-dumpxml default

4. delete the default network.
$ sudo virsh  net-destroy default
$ sudo virsh  net-undefine default

5. restart kimchi.

6. check the ip address changes.
$ sudo virsh  net-dumpxml default

Signed-off-by: ShaoHe Feng <shaohef at linux.vnet.ibm.com>
---
 src/kimchi/model/networks.py | 53 ++++++++++++++++++++++++--------------------
 src/kimchi/network.py        |  3 +++
 2 files changed, 32 insertions(+), 24 deletions(-)

diff --git a/src/kimchi/model/networks.py b/src/kimchi/model/networks.py
index 300ed1c..764379f 100644
--- a/src/kimchi/model/networks.py
+++ b/src/kimchi/model/networks.py
@@ -17,6 +17,8 @@
 # License along with this library; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
 
+import sys
+
 import ipaddr
 import libvirt
 
@@ -27,6 +29,7 @@ from kimchi import xmlutils
 from kimchi.exception import InvalidOperation, InvalidParameter
 from kimchi.exception import MissingParameter, NotFoundError, OperationFailed
 from kimchi.rollbackcontext import RollbackContext
+from kimchi.utils import kimchi_log
 
 
 class NetworksModel(object):
@@ -36,38 +39,40 @@ class NetworksModel(object):
             self._default_network_check()
 
     def _default_network_check(self):
+        def create_defautl_network():
+            try:
+                subnet = self._get_available_address(knetwork.DefaultNetsPool)
+                params = {"name": "default", "connection": "nat",
+                          "subnet": subnet}
+                self.create(params)
+                return conn.networkLookupByName("default")
+            except Exception as e:
+                kimchi_log.error("Fatal: Cannot create default network "
+                                 "because of %s, exit kimchid", e.message)
+                sys.exit(1)
+
         conn = self.conn.get()
-        xml = """
-            <network>
-              <name>default</name>
-              <forward mode='nat'/>
-              <bridge name='virbr0' stp='on' delay='0' />
-              <ip address='192.168.122.1' netmask='255.255.255.0'>
-                <dhcp>
-                  <range start='192.168.122.2' end='192.168.122.254' />
-                </dhcp>
-              </ip>
-            </network>
-        """
         try:
             net = conn.networkLookupByName("default")
         except libvirt.libvirtError:
-            try:
-                net = conn.networkDefineXML(xml)
-            except libvirt.libvirtError, e:
-                cherrypy.log.error("Fatal: Cannot create default network "
-                                   "because of %s, exit kimchid" % e.message,
-                                   severity=logging.ERROR)
-                sys.exit(1)
+            net = create_defautl_network()
 
         if net.isActive() == 0:
             try:
                 net.create()
-            except libvirt.libvirtError, e:
-                cherrypy.log.error("Fatal: Cannot activate default network "
-                                   "because of %s, exit kimchid" % e.message,
-                                   severity=logging.ERROR)
-                sys.exit(1)
+            except libvirt.libvirtError as e:
+                # FIXME we can not distinguish this error from other internal
+                # error by error code.
+                if ("network is already in use by interface"
+                   in e.message.lower()):
+                    # libvirt do not support update IP element, so delete the
+                    # the network and create new one.
+                    net.undefine()
+                    create_defautl_network()
+                else:
+                    kimchi_log.error("Fatal: Cannot activate default network "
+                                     "because of %s, exit kimchid", e.message)
+                    sys.exit(1)
 
     def create(self, params):
         conn = self.conn.get()
diff --git a/src/kimchi/network.py b/src/kimchi/network.py
index 9ad95b4..9bf0c66 100644
--- a/src/kimchi/network.py
+++ b/src/kimchi/network.py
@@ -26,6 +26,9 @@ APrivateNets = ipaddr.IPNetwork("10.0.0.0/8")
 BPrivateNets = ipaddr.IPNetwork("172.16.0.0/12")
 CPrivateNets = ipaddr.IPNetwork('192.168.0.0/16')
 PrivateNets = [CPrivateNets, BPrivateNets, APrivateNets]
+DefaultNetsPool = [ipaddr.IPNetwork('192.168.122.0/23'),
+                   ipaddr.IPNetwork('192.168.124.0/22'),
+                   ipaddr.IPNetwork('192.168.128.0/17')]
 
 
 def get_dev_netaddr(dev):
-- 
1.8.4.2