[PATCH v2 39/47] add lnst.Devices.VirtNetCtl

From: Ondrej Lichtner

Moving the VirtNetCtl class to the lnst.Devices package since it is only
used by the VirtualDevice class.

Signed-off-by: Ondrej Lichtner 
---
 lnst/Devices/VirtNetCtl.py    | 85 +++++++++++++++++++++++++++++++++++++++++++
 lnst/Devices/VirtualDevice.py |  2 +-
 2 files changed, 86 insertions(+), 1 deletion(-)
 create mode 100644 lnst/Devices/VirtNetCtl.py

diff --git a/lnst/Devices/VirtNetCtl.py b/lnst/Devices/VirtNetCtl.py
new file mode 100644
index 0000000..2795baf
--- /dev/null
+++ b/lnst/Devices/VirtNetCtl.py
@@ -0,0 +1,85 @@
+"""
+Defines the VirtNetCtl class used for dynamically adding and removing network
+interface cards to libvirt guests.
+
+Copyright 2017 Red Hat, Inc.
+Licensed under the GNU General Public License, version 2 as
+published by the Free Software Foundation; see COPYING for details.
+"""
+
+__author__ = """
[e-mail] (Ondrej Lichtner)
+"""
+
+import logging
+import libvirt
+from libvirt import libvirtError
+from lnst.Common.LnstError import LnstError
+
+#this is a global object because opening the connection to libvirt in every
+#object instance that uses it sometimes fails - the libvirt server probably
+#can't handle that many connections at a time
+_libvirt_conn = None
+
+def init_libvirt_con():
+    global _libvirt_conn
+    if _libvirt_conn is None:
+        _libvirt_conn = libvirt.open(None)
+
+class VirtNetCtlError(LnstError):
+    pass
+
+class VirtNetCtl(object):
+    _network_template = """
+    <network ipv6='yes'>
+        <name>{0}</name>
+        <bridge name='virbr_{0}' stp='off' delay='0' />
+        <domain name='{0}'/>
+    </network>
+    """
+
+    def __init__(self, name=None):
+        init_libvirt_con()
+
+        if not name:
+            name = self._generate_name()
+        self._name = name
+
+    def _generate_name(self):
+        devs = _libvirt_conn.listNetworks()
+
+        index = 0
+        while True:
+            name = "lnst_net%d" % index
+            index += 1
+            if name not in devs:
+                return name
+
+    def get_name(self):
+        return self._name
+
+    def init(self):
+        try:
+            network_xml = self._network_template.format(self._name)
+            _libvirt_conn.networkCreateXML(network_xml)
+            logging.debug("libvirt network '%s' created" % self._name)
+            return True
+        except libvirtError as e:
+            raise VirtNetCtlError(str(e))
+
+    def cleanup(self):
+        try:
+            network = _libvirt_conn.networkLookupByName(self._name)
+            network.destroy()
+            logging.debug("libvirt network '%s' destroyed" % self._name)
+            return True
+        except libvirtError as e:
+            raise VirtNetCtlError(str(e))
+
+    @classmethod
+    def network_exist(cls, net_name):
+        try:
+            _libvirt_conn.networkLookupByName(net_name)
+            return True
+        except:
+            return False
diff --git a/lnst/Devices/VirtualDevice.py b/lnst/Devices/VirtualDevice.py
index 49fe088..5c41a12 100644
--- a/lnst/Devices/VirtualDevice.py
+++ b/lnst/Devices/VirtualDevice.py
@@ -19,7 +19,7 @@ from lnst.Devices.RemoteDevice import RemoteDevice

# conditional support for libvirt
 if check_process_running("libvirtd"):
-    from lnst.Controller.VirtUtils import VirtNetCtl
+    from lnst.Devices.VirtNetCtl import VirtNetCtl

class VirtualDevice(RemoteDevice):
     """Remote eth device created on the controller through libvirt