Activate interface before duplicate IP check

Runs ifconfig IFACE up before duplicate IP check
so that arping can work correctly in Fuel Setup.

Change-Id: If6336af9f260429db5e8889717554aa0bc325595
Closes-Bug: #1451811

fuelmenu/common/errors.py

@@ -14,5 +14,9 @@
 # under the License.
 
 
+class NetworkException(Exception):
+    pass
+
+
 class BadIPException(Exception):
     pass

fuelmenu/common/network.py

@@ -13,6 +13,7 @@
 # under the License.
 
 from fuelmenu.common.errors import BadIPException
+from fuelmenu.common.errors import NetworkException
 
 import netaddr
 import subprocess
@@ -83,7 +84,12 @@ def duplicateIPExists(ip, iface):
     noout = open('/dev/null', 'w')
     no_dupes = subprocess.call(["arping", "-D", "-c3", "-w1", "-I", iface,
                                ip], stdout=noout, stderr=noout)
-    if no_dupes == 0:
-        return False
-    else:
-        return True
+    return (no_dupes != 0)
+
+
+def upIface(iface):
+    noout = open('/dev/null', 'w')
+    result = subprocess.call(["ifconfig", iface, "up"], stdout=noout,
+                             stderr=noout)
+    if result != 0:
+        raise NetworkException("Failed to up interface {0}".format(iface))

fuelmenu/modules/interfaces.py

@@ -17,6 +17,7 @@ import dhcp_checker.api
 import dhcp_checker.utils
 from fuelmenu.common import dialog
 from fuelmenu.common.errors import BadIPException
+from fuelmenu.common.errors import NetworkException
 from fuelmenu.common.modulehelper import ModuleHelper
 from fuelmenu.common import network
 from fuelmenu.common import puppet
@@ -242,6 +243,12 @@ class interfaces(urwid.WidgetWrap):
                 errors.append(e)
             self.parent.footer.set_text("Scanning for duplicate IP address..")
             if len(responses["ipaddr"]) > 0:
+                if self.netsettings[self.activeiface]['link'].upper() != "UP":
+                    try:
+                        network.upIface(self.activeiface)
+                    except NetworkException as e:
+                        errors.append("Cannot activate {0} to check for "
+                                      "duplicate IP.".format(self.activeiface))
                 if network.duplicateIPExists(responses["ipaddr"],
                                              self.activeiface):
                     errors.append("Duplicate host found with IP {0}.".format(