Allow to pass more than two DNS while putting 2 DNS

Until now, when we pass more than 2 DNS, only the first one is added in
the ifcg-* config files.

This patch-set proves the issue, and proves the correction actually works.

Change-Id: I70a779782ab87cd4f74f3c50b0e649f503b386e3
Closes-Bug: #1716171
(cherry picked from commit 8ddab87c6ee2e80025e9340d806f93921779198b)

2 files changed, 19 insertions, 3 deletions

diff --git a/os_net_config/impl_ifcfg.py b/os_net_config/impl_ifcfg.py
index 3a82597..4f9e0c3 100644
--- a/os_net_config/impl_ifcfg.py
+++ b/os_net_config/impl_ifcfg.py
@@ -398,10 +398,10 @@ class IfcfgNetConfig(os_net_config.NetConfig):
             data += "DHCLIENTARGS=%s\n" % base_opt.dhclient_args
         if base_opt.dns_servers:
             data += "DNS1=%s\n" % base_opt.dns_servers[0]
-            if len(base_opt.dns_servers) == 2:
+            if len(base_opt.dns_servers) >= 2:
                 data += "DNS2=%s\n" % base_opt.dns_servers[1]
-            elif len(base_opt.dns_servers) > 2:
-                logger.warning('ifcfg format supports a max of 2 dns servers.')
+                if len(base_opt.dns_servers) > 2:
+                    logger.warning('ifcfg format supports max 2 resolvers.')
         return data
 
     def _add_routes(self, interface_name, routes=[]):
diff --git a/os_net_config/tests/test_impl_ifcfg.py b/os_net_config/tests/test_impl_ifcfg.py
index 337eeb3..4b91448 100644
--- a/os_net_config/tests/test_impl_ifcfg.py
+++ b/os_net_config/tests/test_impl_ifcfg.py
@@ -876,6 +876,22 @@ DNS2=5.6.7.8
 """
         self.assertEqual(em1_config, self.get_interface_config('em1'))
 
+    def test_interface_more_dns_servers(self):
+        interface1 = objects.Interface('em1', dns_servers=['1.2.3.4',
+                                                           '5.6.7.8',
+                                                           '9.10.11.12'])
+        self.provider.add_interface(interface1)
+        em1_config = """# This file is autogenerated by os-net-config
+DEVICE=em1
+ONBOOT=yes
+HOTPLUG=no
+NM_CONTROLLED=no
+BOOTPROTO=none
+DNS1=1.2.3.4
+DNS2=5.6.7.8
+"""
+        self.assertEqual(em1_config, self.get_interface_config('em1'))
+
     def test_nm_controlled(self):
         interface1 = objects.Interface('em1', nm_controlled=True)
         interface2 = objects.Interface('em2', nm_controlled=True)