Merge lp:~niedbalski/charm-helpers/fix-lp-1489053 into lp:charm-helpers

[Jorge Niedbalski]

This is the charm-helpers fix required to fix LP: #1489053

[Felipe Reyes (freyes)]

Jorge, there is a minor detail in your change.

review: Needs Fixing

[lp:~niedbalski/charm-helpers/fix-lp-1489053]

435. By Jorge Niedbalski on 2015-08-26

addressing freyes comment

[Felipe Reyes (freyes)]

LGTM, all tests pass

review: Approve

=== modified file 'charmhelpers/contrib/network/ip.py'
--- charmhelpers/contrib/network/ip.py	2015-03-03 02:16:13 +0000
+++ charmhelpers/contrib/network/ip.py	2015-08-26 18:44:08 +0000
@@ -435,8 +435,12 @@
 
         rev = dns.reversename.from_address(address)
         result = ns_query(rev)
+
         if not result:
-            return None
+            try:
+                result = socket.gethostbyaddr(address)[0]
+            except:
+                return None
     else:
         result = address
 

=== modified file 'tests/contrib/network/test_ip.py'
--- tests/contrib/network/test_ip.py	2015-03-03 02:16:13 +0000
+++ tests/contrib/network/test_ip.py	2015-08-26 18:44:08 +0000
@@ -670,11 +670,25 @@
             apt_install.assert_called_with('python-dnspython')
         self.assertEquals(hn, 'www.ubuntu.com')
 
+    @patch('charmhelpers.contrib.network.ip.socket.gethostbyaddr')
     @patch('charmhelpers.contrib.network.ip.ns_query')
     @patch('charmhelpers.contrib.network.ip.apt_install')
-    def test_get_hostname_lookup_fail(self, apt_install, ns_query):
+    def test_get_hostname_lookup_fail(self, apt_install, ns_query, socket):
         fake_dns = FakeDNS('www.ubuntu.com')
         ns_query.return_value = []
+        socket.return_value = ()
         with patch(builtin_import, side_effect=[fake_dns, fake_dns]):
             hn = net_ip.get_hostname('4.2.2.1')
         self.assertEquals(hn, None)
+
+    @patch('charmhelpers.contrib.network.ip.socket.gethostbyaddr')
+    @patch('charmhelpers.contrib.network.ip.ns_query')
+    @patch('charmhelpers.contrib.network.ip.apt_install')
+    def test_get_hostname_lookup_fail_gethostbyaddr_fallback(
+            self, apt_install, ns_query, socket):
+        fake_dns = FakeDNS('www.ubuntu.com')
+        ns_query.return_value = []
+        socket.return_value = ("www.ubuntu.com", "", "")
+        with patch(builtin_import, side_effect=[fake_dns]):
+            hn = net_ip.get_hostname('4.2.2.1')
+        self.assertEquals(hn, "www.ubuntu.com")