Add implement of comparing host status

This patch adds implementation of comparing if host status
changed.

Change-Id: Ibd009a27765acd4673ff75ffb097088c091f101b
Implements: bp pythonize-host-and-process-monitor

masakarimonitors/hostmonitor/host_handler/handle_host.py

@@ -19,8 +19,10 @@ from oslo_log import log as oslo_logging
 
 import masakarimonitors.conf
 import masakarimonitors.hostmonitor.host_handler.driver as driver
+from masakarimonitors.hostmonitor.host_handler import hold_host_status
 from masakarimonitors.hostmonitor.host_handler import parse_cib_xml
 from masakarimonitors.i18n import _LE
+from masakarimonitors.i18n import _LI
 from masakarimonitors.i18n import _LW
 from masakarimonitors import utils
 
@@ -38,6 +40,7 @@ class HandleHost(driver.DriverBase):
         super(HandleHost, self).__init__()
         self.my_hostname = socket.gethostname()
         self.xml_parser = parse_cib_xml.ParseCibXml()
+        self.status_holder = hold_host_status.HostHoldStatus()
 
     def _check_host_status_by_crmadmin(self):
         try:
@@ -78,6 +81,43 @@ class HandleHost(driver.DriverBase):
 
         return out
 
+    def _check_if_status_changed(self, node_state_tag_list):
+
+        # Check if host status changed.
+        for node_state_tag in node_state_tag_list:
+
+            # hostmonitor doesn't monitor itself.
+            if node_state_tag.get('uname') == self.my_hostname:
+                continue
+
+            # Get current status and old status.
+            current_status = node_state_tag.get('crmd')
+            old_status = self.status_holder.get_host_status(
+                node_state_tag.get('uname'))
+
+            # If old_status is None, This is first get of host status.
+            if old_status is None:
+                msg = ("Recognized '%s' as a new member of cluster."
+                       " Host status is '%s'.") \
+                    % (node_state_tag.get('uname'), current_status)
+                LOG.info(_LI("%s"), msg)
+                self.status_holder.set_host_status(node_state_tag)
+                continue
+
+            # Output host status.
+            msg = ("'%s' is '%s'.") % (node_state_tag.get('uname'),
+                                       current_status)
+            LOG.info(_LI("%s"), msg)
+
+            # If host status changed, send a notification.
+            if current_status != old_status:
+                # TODO(takahara.kengo)
+                # Implement the notification processing.
+                pass
+
+            # Update host status.
+            self.status_holder.set_host_status(node_state_tag)
+
     def _check_host_status_by_cibadmin(self):
         # Get xml of cib info.
         cib_xml = self._get_cib_xml()
@@ -101,6 +141,9 @@ class HandleHost(driver.DriverBase):
             raise Exception(
                 "Failed to get node_state tag from cib xml.")
 
+        # Check if status changed.
+        self._check_if_status_changed(node_state_tag_list)
+
         return 0
 
     def stop(self):

masakarimonitors/hostmonitor/host_handler/hold_host_status.py

@@ -0,0 +1,46 @@
+# Copyright(c) 2016 Nippon Telegraph and Telephone Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+class HostHoldStatus(object):
+    """Hold host status.
+
+    This class holds the host status.
+    """
+
+    def __init__(self):
+        # host_status is dictionary like {'hostname': 'online'}.
+        self.host_status = {}
+
+    def set_host_status(self, node_state_tag):
+        """Setter method.
+
+        This method set host status by node_state tag of cib xml.
+
+        :params node_state_tag: node_state tag of cib xml.
+        """
+        self.host_status[node_state_tag.get('uname')] = \
+            node_state_tag.get('crmd')
+
+    def get_host_status(self, hostname):
+        """Getter method.
+
+        This method returns the requested host status.
+        host status is 'online' or 'offline'.
+
+        :params hostname: Hostname to get status.
+
+        :returns: Host status.
+        """
+        return self.host_status.get(hostname)

masakarimonitors/tests/unit/hostmonitor/host_handler/test_hold_host_status.py

@@ -0,0 +1,43 @@
+# Copyright(c) 2016 Nippon Telegraph and Telephone Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import testtools
+from xml.etree import ElementTree
+
+import eventlet
+
+from masakarimonitors.hostmonitor.host_handler import hold_host_status
+
+eventlet.monkey_patch(os=False)
+
+NODE_STATE_XML = '<node_state uname="masakari-node" crmd="online">' \
+                 '  <test hoge="hoge"/>' \
+                 '</node_state>'
+NODE_STATE_TAG = ElementTree.fromstring(NODE_STATE_XML)
+
+
+class TestHostHoldStatus(testtools.TestCase):
+
+    def setUp(self):
+        super(TestHostHoldStatus, self).setUp()
+
+    def test_set_host_status(self):
+        obj = hold_host_status.HostHoldStatus()
+        obj.set_host_status(NODE_STATE_TAG)
+        self.assertEqual('online', obj.get_host_status('masakari-node'))
+
+    def test_get_host_status(self):
+        obj = hold_host_status.HostHoldStatus()
+        obj.set_host_status(NODE_STATE_TAG)
+        self.assertEqual('online', obj.get_host_status('masakari-node'))