From 3fc3c01ba614d6210e4cc7426aa278688c88e5d4 Mon Sep 17 00:00:00 2001
From: Julien Fortin <julien@cumulusnetworks.com>
Date: Tue, 27 Dec 2016 17:03:19 +0100
Subject: [PATCH] addons: address: purge ifalias when no alias keyword is
 provided

Ticket: CM-13044
Reviewed By: Roopa, Nikhil G, Daniel W,
Testing Done:

For some reason we can't simply write into a file when we want to purge the
ifalias, we have to exec a command. I wasn't able to make it work in any
other way.

add an alias to an interface, ifreload, ip link show interface
modify it, ifreload, ip link show interface
remove it, ifreload, ip link show interface

Signed-off-by: Julien Fortin <julien@cumulusnetworks.com>
---
 addons/address.py          | 11 ++++++++---
 ifupdownaddons/iproute2.py |  7 +++++--
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/addons/address.py b/addons/address.py
index aa86676..fc9fa89 100644
--- a/addons/address.py
+++ b/addons/address.py
@@ -446,6 +446,14 @@ class address(moduleBase):
     def _up(self, ifaceobj, ifaceobj_getfunc=None):
         if not self.ipcmd.link_exists(ifaceobj.name):
             return
+
+        alias = ifaceobj.get_attr_value_first('alias')
+        current_alias = self.ipcmd.link_get_alias(ifaceobj.name)
+        if alias and alias != current_alias:
+            self.ipcmd.link_set_alias(ifaceobj.name, alias)
+        elif not alias and current_alias:
+            self.ipcmd.link_set_alias(ifaceobj.name, '')
+
         addr_method = ifaceobj.addr_method
         force_reapply = False
         try:
@@ -472,9 +480,6 @@ class address(moduleBase):
                                       force_reapply)
         self._process_mtu_config(ifaceobj, ifaceobj_getfunc)
 
-        alias = ifaceobj.get_attr_value_first('alias')
-        if alias:
-           self.ipcmd.link_set_alias(ifaceobj.name, alias)
         try:
             self.ipcmd.batch_commit()
         except Exception as e:
diff --git a/ifupdownaddons/iproute2.py b/ifupdownaddons/iproute2.py
index a7aa8ac..72eda66 100644
--- a/ifupdownaddons/iproute2.py
+++ b/ifupdownaddons/iproute2.py
@@ -477,8 +477,11 @@ class iproute2(utilsBase):
         self._cache_update([ifacename, 'mtu'], mtu)
 
     def link_set_alias(self, ifacename, alias):
-        utils.exec_commandl(['ip', 'link', 'set', 'dev', ifacename,
-                             'alias', alias])
+        if not alias:
+            utils.exec_user_command('echo "" > /sys/class/net/%s/ifalias'
+                                    % ifacename)
+        else:
+            self.write_file('/sys/class/net/%s/ifalias' % ifacename, alias)
 
     def link_get_alias(self, ifacename):
         return self.read_file_oneline('/sys/class/net/%s/ifalias'