Change utils.get_ipmi_address(node) to always return IPv4 address

It is possible for ipmi_address, ilo_address, or drac_host to be
hostnames. However, we need an IPv4 address.

Closes-Bug: #1415040
Change-Id: I221e63ffe8881ad26f512fb29328ffcad8e26b45

ironic_discoverd/test/test_utils.py

@@ -44,6 +44,29 @@ class TestCheckIsAdmin(base.BaseTest):
                           utils.check_is_admin, 'token')
 
 
+@mock.patch('ironic_discoverd.node_cache.NodeInfo')
+class TestGetIpmiAddress(base.BaseTest):
+    def test_ipv4_in_resolves(self, mock_node):
+        node = mock_node.return_value
+        node.driver_info.get.return_value = '192.168.1.1'
+        ip = utils.get_ipmi_address(node)
+        self.assertEqual(ip, '192.168.1.1')
+
+    @mock.patch('socket.gethostbyname')
+    def test_good_hostname_resolves(self, mock_socket, mock_node):
+        node = mock_node.return_value
+        node.driver_info.get.return_value = 'www.example.com'
+        mock_socket.return_value = '192.168.1.1'
+        ip = utils.get_ipmi_address(node)
+        mock_socket.assert_called_once_with('www.example.com')
+        self.assertEqual(ip, '192.168.1.1')
+
+    def test_bad_hostname_errors(self, mock_node):
+        node = mock_node.return_value
+        node.driver_info.get.return_value = 'meow'
+        self.assertRaises(utils.Error, utils.get_ipmi_address, node)
+
+
 @mock.patch.object(eventlet.greenthread, 'sleep', lambda _: None)
 class TestRetryOnConflict(unittest.TestCase):
     def test_retry_on_conflict(self):

ironic_discoverd/utils.py

@@ -13,6 +13,7 @@
 
 import logging
 import re
+import socket
 
 import eventlet
 from ironicclient import client
@@ -76,7 +77,12 @@ def get_ipmi_address(node):
     for name in ('ipmi_address', 'ilo_address', 'drac_host'):
         value = node.driver_info.get(name)
         if value:
-            return value
+            try:
+                ip = socket.gethostbyname(value)
+                return ip
+            except socket.gaierror:
+                msg = ('Failed to resolve the hostname (%s) for node %s')
+                raise Error(msg % (value, node.uuid))
 
 
 def retry_on_conflict(call, *args, **kwargs):