Add support to change root password

Change the configured root's password in percona and update the leader
settings.

Change-Id: I7168a96cac7a3b4df7fcfa1afc6f35076748578b
Partial-Bug: 1436093

hooks/percona_hooks.py

@@ -105,6 +105,7 @@ from percona_utils import (
     pxc_installed,
     update_bootstrap_uuid,
     LeaderNoBootstrapUUIDError,
+    update_root_password,
 )
 
 
@@ -338,6 +339,11 @@ def config_changed():
 
     open_port(DEFAULT_MYSQL_PORT)
 
+    # the password needs to be updated only if the node was already
+    # bootstrapped
+    if bootstrapped:
+        update_root_password()
+
 
 @hooks.hook('cluster-relation-joined')
 def cluster_joined():

hooks/percona_utils.py

@@ -820,3 +820,30 @@ def pxc_installed():
     @returns: boolean: indicating installation
     '''
     return os.path.exists('/usr/sbin/mysqld')
+
+
+def update_root_password():
+    """Update root password if needed
+
+    :returns: `False` when configured password has not changed
+    """
+
+    cfg = config()
+    if not cfg.changed('root-password'):
+        return False
+
+    m_helper = get_db_helper()
+
+    # password that needs to be set
+    new_root_passwd = cfg['root-password']
+    m_helper.set_mysql_root_password(new_root_passwd)
+
+    # check the password was changed
+    try:
+        m_helper.connect(user='root', password=new_root_passwd)
+        m_helper.execute('select 1;')
+    except OperationalError as ex:
+        log("Error connecting using new passowrd: %s" % str(ex), level=DEBUG)
+        log(('Cannot connect using new password, not updating password in '
+             'the relation'), level=WARNING)
+        return

tests/basic_deployment.py

@@ -13,6 +13,9 @@ from charmhelpers.contrib.openstack.amulet.deployment import (
 from charmhelpers.contrib.amulet.utils import AmuletUtils
 
 
+PXC_ROOT_PASSWD = 'ubuntu'
+
+
 class BasicDeployment(OpenStackAmuletDeployment):
 
     utils = AmuletUtils()
@@ -73,7 +76,8 @@ class BasicDeployment(OpenStackAmuletDeployment):
     def _get_configs(self):
         """Configure all of the services."""
         cfg_percona = {'min-cluster-size': self.units,
-                       'vip': self.vip}
+                       'vip': self.vip,
+                       'root-password': PXC_ROOT_PASSWD}
 
         cfg_ha = {'debug': True,
                   'corosync_key': ('xZP7GDWV0e8Qs0GxWThXirNNYlScgi3sRTdZk/IXKD'
@@ -240,6 +244,31 @@ class BasicDeployment(OpenStackAmuletDeployment):
 
         assert self.is_port_open(address=self.vip), 'cannot connect to vip'
 
+    def test_change_root_password(self):
+        """
+        Change root password and verify the change was effectively applied.
+        """
+
+        new_root_passwd = 'openstack'
+
+        u = self.master_unit
+        root_password, _ = PXC_ROOT_PASSWD
+        cmd = "mysql -uroot -p{} -e\"select 1;\" ".format(root_password)
+        output, code = u.run(cmd)
+
+        assert code == 0, output
+
+        self.d.configure('percona-cluster', {'root-password': new_root_passwd})
+
+        time.sleep(5)  # give some time to the unit to start the hook
+        self.d.sentry.wait()  # wait until the hook finishes
+
+        # try to connect using the new root password
+        cmd = "mysql -uroot -p{} -e\"select 1;\" ".format(new_root_passwd)
+        output, code = u.run(cmd)
+
+        assert code == 0, output
+
     def find_master(self, ha=True):
         for unit in self.d.sentry['percona-cluster']:
             if not ha:

unit_tests/test_percona_utils.py

@@ -523,6 +523,8 @@ class TestUpdateBootstrapUUID(CharmTestCase):
         'relation_set',
         'is_leader',
         'leader_set',
+        'config',
+        'leader_get',
     ]
 
     def setUp(self):
@@ -583,3 +585,24 @@ class TestUpdateBootstrapUUID(CharmTestCase):
         self.get_wsrep_value.side_effect = fake_wsrep
         self.assertRaises(percona_utils.InconsistentUUIDError,
                           percona_utils.update_bootstrap_uuid)
+
+    @mock.patch('charmhelpers.contrib.database.mysql.leader_set')
+    @mock.patch('charmhelpers.contrib.database.mysql.is_leader')
+    @mock.patch('charmhelpers.contrib.database.mysql.leader_get')
+    def test_update_root_password(self, mock_leader_get, mock_is_leader,
+                                  mock_leader_set):
+        cur_password = 'openstack'
+        new_password = 'ubuntu'
+        leader_config = {'mysql.passwd': cur_password}
+        mock_leader_get.side_effect = lambda k: leader_config[k]
+        mock_is_leader.return_value = True
+
+        self.config.side_effect = self.test_config.get
+        self.assertFalse(percona_utils.update_root_password())
+
+        self.test_config.set_previous('root-password', cur_password)
+        self.test_config.set('root-password', new_password)
+        percona_utils.update_root_password()
+
+        mock_leader_set.assert_called_with(
+            settings={'mysql.passwd': new_password})

unit_tests/test_utils.py

@@ -70,10 +70,24 @@ class TestConfig(object):
 
     def __init__(self):
         self.config = get_default_config()
+        self.config_prev = {}
+
+    def previous(self, k):
+        return self.config_prev[k] if k in self.config_prev else self.config[k]
+
+    def set_previous(self, k, v):
+        self.config_prev[k] = v
+
+    def unset_previous(self, k):
+        if k in self.config_prev:
+            self.config_prev.pop(k)
+
+    def changed(self, k):
+        return self.get(k) != self.previous(k)
 
     def get(self, attr=None):
         if not attr:
-            return self.get_all()
+            return self
         try:
             return self.config[attr]
         except KeyError:
@@ -87,6 +101,9 @@ class TestConfig(object):
             raise KeyError
         self.config[attr] = value
 
+    def __getitem__(self, k):
+        return self.get(k)
+
 
 class TestRelation(object):