Enable renaming of interfaces without reboot

When using persist_mapping to rename nics, you can either use
--no-activate then reboot, or with this patch, allow activation
and we'll take the device links down and rename on the fly avoiding
the need for a reboot.

Change-Id: Ife9486c9f5447e9c7a55f90ba075e22b6344ad67

3 files changed, 28 insertions, 2 deletions

diff --git a/os_net_config/__init__.py b/os_net_config/__init__.py
index 5e1d091..e1bee26 100644
--- a/os_net_config/__init__.py
+++ b/os_net_config/__init__.py
@@ -125,3 +125,17 @@ class NetConfig(object):
     def ifup(self, interface, iftype='interface'):
         msg = 'running ifup on %s: %s' % (iftype, interface)
         self.execute(msg, '/sbin/ifup', interface)
+
+    def ifrename(self, oldname, newname):
+        msg = 'renaming %s to %s: ' % (oldname, newname)
+        # ifdown isn't enough when renaming, we need the link down
+        for name in (oldname, newname):
+            if utils._is_active_nic(name):
+                self.execute(msg, '/sbin/ip',
+                             'link', 'set', 'dev', name, 'down')
+                self.execute(msg, '/sbin/ip',
+                             'link', 'set', 'dev', name, 'link', 'down')
+        self.execute(msg, '/sbin/ip',
+                     'link', 'set', 'dev', oldname, 'name', newname)
+        self.execute(msg, '/sbin/ip',
+                     'link', 'set', 'dev', newname, 'up')
diff --git a/os_net_config/impl_ifcfg.py b/os_net_config/impl_ifcfg.py
index 78433d8..47f32a6 100644
--- a/os_net_config/impl_ifcfg.py
+++ b/os_net_config/impl_ifcfg.py
@@ -51,6 +51,7 @@ class IfcfgNetConfig(os_net_config.NetConfig):
         self.route_data = {}
         self.bridge_data = {}
         self.member_names = {}
+        self.renamed_interfaces = {}
         logger.info('Ifcfg net config provider created.')
 
     def child_members(self, name):
@@ -172,6 +173,11 @@ class IfcfgNetConfig(os_net_config.NetConfig):
         if interface.routes:
             self._add_routes(interface.name, interface.routes)
 
+        if interface.renamed:
+            logger.info("Interface %s being renamed to %s"
+                        % (interface.hwname, interface.name))
+            self.renamed_interfaces[interface.hwname] = interface.name
+
     def add_vlan(self, vlan):
         """Add a Vlan object to the net config object.
 
@@ -275,6 +281,9 @@ class IfcfgNetConfig(os_net_config.NetConfig):
             for bridge in restart_bridges:
                 self.ifdown(bridge, iftype='bridge')
 
+            for oldname, newname in self.renamed_interfaces.iteritems():
+                self.ifrename(oldname, newname)
+
         for location, data in update_files.iteritems():
             self.write_config(location, data)
 
diff --git a/os_net_config/objects.py b/os_net_config/objects.py
index 8115b38..bb50f18 100644
--- a/os_net_config/objects.py
+++ b/os_net_config/objects.py
@@ -133,11 +133,14 @@ class _BaseOpts(object):
                  persist_mapping=False):
         numbered_nic_names = _numbered_nics(nic_mapping)
         self.hwaddr = None
+        self.hwname = None
+        self.renamed = False
         if name in numbered_nic_names:
             if persist_mapping:
                 self.name = name
-                hwname = numbered_nic_names[name]
-                self.hwaddr = utils.interface_mac(hwname)
+                self.hwname = numbered_nic_names[name]
+                self.hwaddr = utils.interface_mac(self.hwname)
+                self.renamed = True
             else:
                 self.name = numbered_nic_names[name]
         else: