Require maintenance mode for setting IPMI credentials

Otherwise Ironic power sync loop is going to make us cry.
Implements: blueprint setup-ipmi-credentials-take2

Change-Id: I2796ba2d74ba328605e7133139b1b3ebfba7ce36

ironic_discoverd/introspect.py

@@ -38,6 +38,11 @@ def _validate_ipmi_credentials(node, new_ipmi_credentials):
         raise utils.Error(
             'IPMI credentials setup is disabled in configuration')
 
+    if not node.maintenance:
+        # Otherwise Ironic is going to interfer
+        raise utils.Error('Node should be in maintenance mode to set '
+                          'IPMI credentials on it')
+
     new_username, new_password = new_ipmi_credentials
     if not new_username:
         new_username = node.driver_info.get('ipmi_username')

ironic_discoverd/test/test_introspect.py

@@ -285,6 +285,7 @@ class TestSetIpmiCredentials(BaseTest):
         conf.CONF.set('discoverd', 'enable_setting_ipmi_credentials', 'true')
         self.new_creds = ('user', 'password')
         self.cached_node.options['new_ipmi_credentials'] = self.new_creds
+        self.node.maintenance = True
 
     def test_ok(self, client_mock, add_mock, filters_mock):
         cli = self._prepare(client_mock)
@@ -347,3 +348,10 @@ class TestSetIpmiCredentials(BaseTest):
 
         self.assertRaises(utils.Error, introspect.introspect, self.uuid,
                           new_ipmi_credentials=self.new_creds)
+
+    def test_require_maintenance(self, client_mock, add_mock, filters_mock):
+        self.node.maintenance = False
+        self._prepare(client_mock)
+
+        self.assertRaises(utils.Error, introspect.introspect, self.uuid,
+                          new_ipmi_credentials=self.new_creds)