Bootstrap action after a cold boot

After a cold boot, percona-cluster will require administrative
intervention. One node will need to bootstrap per upstream
Percona Cluster documentation:
https://www.percona.com/blog/2014/09/01/galera-replication-how-to-recover-a-pxc-cluster/

This change adds an action to bootstrap a single node. On the other
nodes systemd will be attempting to start percona. Once the bootstrapped
node is up the others will join automatically.

Change-Id: Id9a860edc343ee5dbd7fc8c5ce3b4420ec6e134e
Partial-Bug: #1744393

actions.yaml

@@ -24,3 +24,11 @@ complete-cluster-series-upgrade:
     peers for wsrep replication.
     This action should be performed on the current leader. Note the leader may
     have changed during the series upgrade process.
+bootstrap-pxc:
+  description: |
+    Bootstrap this unit of Percona.
+    *WARNING* This action will bootstrap this unit of Percona cluster. This
+    should only occur in a recovery scenario. Make sure this unit has the
+    highest sequence number in grstate.dat or data loss may occur.
+    See upstream Percona documentation for context
+    https://www.percona.com/blog/2014/09/01/galera-replication-how-to-recover-a-pxc-cluster/

actions/actions.py

@@ -15,6 +15,7 @@ def _add_path(path):
     if path not in sys.path:
         sys.path.insert(1, path)
 
+
 _add_path(_hooks)
 _add_path(_root)
 
@@ -32,13 +33,8 @@ from charmhelpers.core.host import (
     lsb_release,
 )
 
-from percona_utils import (
-    pause_unit_helper,
-    resume_unit_helper,
-    register_configs,
-    _get_password,
-)
-from percona_hooks import config_changed
+import percona_utils
+import percona_hooks
 
 
 def pause(args):
@@ -46,7 +42,7 @@ def pause(args):
 
     @raises Exception should the service fail to stop.
     """
-    pause_unit_helper(register_configs())
+    percona_utils.pause_unit_helper(percona_utils.register_configs())
 
 
 def resume(args):
@@ -54,10 +50,10 @@ def resume(args):
 
     @raises Exception should the service fail to start.
     """
-    resume_unit_helper(register_configs())
+    percona_utils.resume_unit_helper(percona_utils.register_configs())
     # NOTE(ajkavanagh) - we force a config_changed pseudo-hook to see if the
     # unit needs to bootstrap or restart it's services here.
-    config_changed()
+    percona_hooks.config_changed()
 
 
 def complete_cluster_series_upgrade(args):
@@ -71,14 +67,14 @@ def complete_cluster_series_upgrade(args):
         # Unset cluster_series_upgrading
         leader_set(cluster_series_upgrading="")
         leader_set(cluster_series_upgrade_leader="")
-    config_changed()
+    percona_hooks.config_changed()
 
 
 def backup(args):
     basedir = (action_get("basedir")).lower()
     compress = action_get("compress")
     incremental = action_get("incremental")
-    sstpw = _get_password("sst-password")
+    sstpw = percona_utils._get_password("sst-password")
     optionlist = []
 
     # innobackupex will not create recursive dirs that do not already exist,
@@ -115,10 +111,35 @@ def backup(args):
                     "and check the status of the database")
 
 
+def bootstrap_pxc(args):
+    try:
+        # Force safe to bootstrap
+        percona_utils.set_grstate_safe_to_bootstrap()
+        # Boostrap this node
+        percona_utils.bootstrap_pxc()
+    except (percona_utils.GRStateFileNotFound, OSError) as e:
+        action_set({
+            'output': e.output,
+            'return-code': e.returncode})
+        action_fail("The GRState file does not exist or cannot be written to.")
+    except (subprocess.CalledProcessError, Exception) as e:
+        action_set({
+            'output': e.output,
+            'return-code': e.returncode,
+            'traceback': traceback.format_exc()})
+        action_fail("The bootstrap-pxc failed. "
+                    "See traceback in show-action-output")
+    action_set({
+        'output': "Bootstrap succeded. "
+                  "Wait for the other units to run update-status"})
+    percona_utils.assess_status(percona_utils.register_configs())
+
+
 # A dictionary of all the defined actions to callables (which take
 # parsed arguments).
 ACTIONS = {"pause": pause, "resume": resume, "backup": backup,
-           "complete-cluster-series-upgrade": complete_cluster_series_upgrade}
+           "complete-cluster-series-upgrade": complete_cluster_series_upgrade,
+           "bootstrap-pxc": bootstrap_pxc}
 
 
 def main(args):

actions/bootstrap-pxc

@@ -0,0 +1 @@
+actions.py

unit_tests/test_actions.py

@@ -6,11 +6,9 @@ from test_utils import CharmTestCase
 # we have to patch out harden decorator because hooks/percona_hooks.py gets
 # imported via actions.py and will freak out if it trys to run in the context
 # of a test.
-with patch('percona_utils.register_configs') as configs, \
-        patch('charmhelpers.contrib.hardening.harden.harden') as mock_dec:
+with patch('charmhelpers.contrib.hardening.harden.harden') as mock_dec:
     mock_dec.side_effect = (lambda *dargs, **dkwargs: lambda f:
                             lambda *args, **kwargs: f(*args, **kwargs))
-    configs.return_value = 'test-config'
     from actions import actions
 
 
@@ -18,9 +16,10 @@ class PauseTestCase(CharmTestCase):
 
     def setUp(self):
         super(PauseTestCase, self).setUp(
-            actions, ["pause_unit_helper"])
+            actions.percona_utils, ["pause_unit_helper", "register_configs"])
 
     def test_pauses_services(self):
+        self.register_configs.return_value = "test-config"
         actions.pause([])
         self.pause_unit_helper.assert_called_once_with('test-config')
 
@@ -29,10 +28,12 @@ class ResumeTestCase(CharmTestCase):
 
     def setUp(self):
         super(ResumeTestCase, self).setUp(
-            actions, ["resume_unit_helper"])
+            actions.percona_utils, ["resume_unit_helper", "register_configs"])
 
     def test_pauses_services(self):
-        with patch('actions.actions.config_changed') as config_changed:
+        self.register_configs.return_value = "test-config"
+        with patch('actions.actions.percona_hooks.config_changed'
+                   ) as config_changed:
             actions.resume([])
             self.resume_unit_helper.assert_called_once_with('test-config')
             config_changed.assert_called_once_with()
@@ -42,22 +43,25 @@ class CompleteClusterSeriesUpgrade(CharmTestCase):
 
     def setUp(self):
         super(CompleteClusterSeriesUpgrade, self).setUp(
-            actions, ["config_changed", "is_leader", "leader_set"])
+            actions, ["is_leader", "leader_set"])
 
     def test_leader_complete_series_upgrade(self):
         self.is_leader.return_value = True
-
         calls = [mock.call(cluster_series_upgrading=""),
                  mock.call(cluster_series_upgrade_leader="")]
-        actions.complete_cluster_series_upgrade([])
-        self.leader_set.assert_has_calls(calls)
-        self.config_changed.assert_called_once_with()
+        with patch('actions.actions.percona_hooks.config_changed'
+                   ) as config_changed:
+            actions.complete_cluster_series_upgrade([])
+            self.leader_set.assert_has_calls(calls)
+            config_changed.assert_called_once_with()
 
     def test_non_leader_complete_series_upgrade(self):
         self.is_leader.return_value = False
-        actions.complete_cluster_series_upgrade([])
-        self.leader_set.assert_not_called()
-        self.config_changed.assert_called_once_with()
+        with patch('actions.actions.percona_hooks.config_changed'
+                   ) as config_changed:
+            actions.complete_cluster_series_upgrade([])
+            self.leader_set.assert_not_called()
+            config_changed.assert_called_once_with()
 
 
 class MainTestCase(CharmTestCase):