Implement method in openstack metadata service

- Implement `get_kms_host` method

Change-Id: I62fdfbd3f99bdcad096911bd34bb363cfc15d4ef

cloudbaseinit/metadata/services/baseopenstackservice.py

@@ -308,3 +308,16 @@ class BaseOpenStackService(base.BaseMetadataService):
                 LOG.debug("user_data metadata not present")
 
         return list(set((cert.strip() for cert in certs)))
+
+    def get_kms_host(self):
+        meta_data = self._get_meta_data()
+        meta = meta_data.get("meta")
+
+        if meta and "kms_host" in meta:
+            kms_host = meta["kms_host"]
+        elif "kms_host" in meta_data:
+            kms_host = meta_data["kms_host"]
+        else:
+            kms_host = None
+
+        return kms_host

cloudbaseinit/tests/metadata/services/test_baseopenstackservice.py

@@ -528,3 +528,26 @@ class TestBaseOpenStackService(unittest.TestCase):
 
         self.assertIsNone(network_details)
         self.assertTrue(mock_log_exception.called)
+
+    @mock.patch(MODPATH +
+                ".BaseOpenStackService._get_meta_data")
+    def _test_get_kms_host(self, mock_get_meta_data, meta_data):
+        mock_get_meta_data.return_value = meta_data
+        response = self._service.get_kms_host()
+        mock_get_meta_data.assert_called_once_with()
+        if meta_data and 'kms_host' in meta_data:
+            self.assertEqual(meta_data['kms_host'], response)
+        elif meta_data and 'kms_host' in meta_data.get('meta'):
+            self.assertEqual(meta_data.get('meta')['kms_host'], response)
+        else:
+            self.assertIsNone(response)
+
+    def test_get_kms_host(self):
+        self._test_get_kms_host(meta_data={'kms_host': 'fake host'})
+
+    def test_get_kms_host_in_meta(self):
+        self._test_get_kms_host(
+            meta_data={'meta': {'kms_host': 'fake host'}})
+
+    def test_get_kms_host_no_pass(self):
+        self._test_get_kms_host(meta_data={})

doc/source/services.rst

@@ -53,6 +53,7 @@ Capabilities:
     * admin user password
     * post admin user password (only once)
     * user data
+    * kms host
 
 Config options for `openstack` section:
 
@@ -105,6 +106,7 @@ Capabilities:
     * admin user name
     * admin user password
     * user data
+    * kms host
 
 Config options for `config_drive` section: