python: Various fixes to the python scripts

src/lxc/lxc-start-ephemeral.in

@@ -134,7 +134,9 @@ dest = lxc.Container(os.path.basename(dest_path), args.lxcpath)
 dest.load_config(orig.config_file_name)
 dest.set_config_item("lxc.utsname", dest.name)
 dest.set_config_item("lxc.rootfs", os.path.join(dest_path, "rootfs"))
-dest.set_config_item("lxc.network.hwaddr", randomMAC())
+for nic in dest.network:
+    if hasattr(nic, 'hwaddr'):
+        nic.hwaddr = randomMAC()
 
 overlay_dirs = [(orig.get_config_item("lxc.rootfs"), "%s/rootfs/" % dest_path)]
 

src/python-lxc/lxc/__init__.py

@@ -412,7 +412,10 @@ class Container(_lxc.Container):
             Set a config key to a provided value.
             The value can be a list for the keys supporting multiple values.
         """
-        old_value = self.get_config_item(key)
+        try:
+            old_value = self.get_config_item(key)
+        except KeyError:
+            old_value = None
 
         # Check if it's a list
         def set_key(key, value):