Merge lp:~freyes/charm-helpers/current-dc-none into lp:charm-helpers

[Felipe Reyes]

Dear Charmers,

This patch improves charmhelpers.contrib.hahelpers.cluster:is_crm_dc() to consider the case when the current DC is NONE.

To allow the @retry_on_exception() decorator work when current DC is NONE or when 'crm status' fails the exception CRMDCNotFound is raised.

Best,

[Liam Young (gnuoy)]

Approve

review: Approve

=== modified file 'charmhelpers/contrib/hahelpers/cluster.py'
--- charmhelpers/contrib/hahelpers/cluster.py	2015-06-03 08:15:41 +0000
+++ charmhelpers/contrib/hahelpers/cluster.py	2015-06-05 19:09:42 +0000
@@ -64,6 +64,10 @@
     pass
 
 
+class CRMDCNotFound(Exception):
+    pass
+
+
 def is_elected_leader(resource):
     """
     Returns True if the charm executing this is the elected cluster leader.
@@ -116,8 +120,9 @@
         status = subprocess.check_output(cmd, stderr=subprocess.STDOUT)
         if not isinstance(status, six.text_type):
             status = six.text_type(status, "utf-8")
-    except subprocess.CalledProcessError:
-        return False
+    except subprocess.CalledProcessError as ex:
+        raise CRMDCNotFound(str(ex))
+
     current_dc = ''
     for line in status.split('\n'):
         if line.startswith('Current DC'):
@@ -125,10 +130,14 @@
             current_dc = line.split(':')[1].split()[0]
     if current_dc == get_unit_hostname():
         return True
+    elif current_dc == 'NONE':
+        raise CRMDCNotFound('Current DC: NONE')
+
     return False
 
 
-@retry_on_exception(5, base_delay=2, exc_type=CRMResourceNotFound)
+@retry_on_exception(5, base_delay=2,
+                    exc_type=(CRMResourceNotFound, CRMDCNotFound))
 def is_crm_leader(resource, retry=False):
     """
     Returns True if the charm calling this is the elected corosync leader,

=== modified file 'tests/contrib/hahelpers/test_cluster_utils.py'
--- tests/contrib/hahelpers/test_cluster_utils.py	2015-05-20 22:56:01 +0000
+++ tests/contrib/hahelpers/test_cluster_utils.py	2015-06-05 19:09:42 +0000
@@ -1,4 +1,3 @@
-
 from mock import patch, MagicMock, call
 
 from subprocess import CalledProcessError
@@ -24,6 +23,18 @@
             Started: [ juju-trusty-machine-1 juju-trusty-machine-2 juju-trusty-machine-3 ]
 '''
 
+CRM_DC_NONE = b'''
+Last updated: Thu May 14 14:46:35 2015
+Last change: Thu May 14 14:43:51 2015 via crmd on juju-trusty-machine-1
+Stack: corosync
+Current DC: NONE
+1 Nodes configured, 2 expected votes
+0 Resources configured
+
+
+Node node1: UNCLEAN (offline)
+'''
+
 
 class ClusterUtilsTests(TestCase):
     def setUp(self):
@@ -68,8 +79,11 @@
     @patch('subprocess.check_output')
     def test_is_crm_dc_no_cluster(self, check_output):
         '''It is not leader if there is no cluster up'''
-        check_output.side_effect = CalledProcessError(1, 'crm')
-        self.assertFalse(cluster_utils.is_crm_dc())
+        def r(*args, **kwargs):
+            raise CalledProcessError(1, 'crm')
+
+        check_output.side_effect = r
+        self.assertRaises(cluster_utils.CRMDCNotFound, cluster_utils.is_crm_dc)
 
     @patch('subprocess.check_output')
     def test_is_crm_dc_false(self, check_output):
@@ -79,6 +93,13 @@
         self.assertFalse(cluster_utils.is_crm_dc())
 
     @patch('subprocess.check_output')
+    def test_is_crm_dc_current_none(self, check_output):
+        '''It determines its unit is leader'''
+        self.get_unit_hostname.return_value = 'juju-trusty-machine-1'
+        check_output.return_value = CRM_DC_NONE
+        self.assertRaises(cluster_utils.CRMDCNotFound, cluster_utils.is_crm_dc)
+
+    @patch('subprocess.check_output')
     def test_is_crm_leader(self, check_output):
         '''It determines its unit is leader'''
         self.get_unit_hostname.return_value = 'node1'