More code-review related fixes

- Add missing delete_cluster.
- Simplify parts of the code by removing exception handlers where
  they are not needed.
- Fix typos.

patroni/ctl.py

@@ -661,11 +661,8 @@ def touch_member(config, dcs):
         'state': p.state,
         'role': p.role
     }
-    try:
-        dcs.touch_member(json.dumps(data, separators=(',', ':')), permanent=True)
-    except DCSError:
-        return False
-    return True
+
+    return dcs.touch_member(json.dumps(data, separators=(',', ':')), permanent=True)
 
 
 def set_defaults(config, cluster_name):
@@ -694,11 +691,9 @@ def scaffold(cluster_name, config_file, dcs, sysid):
 
     set_defaults(config, cluster_name)
 
-    try:
-        # make sure the leader keys will never expire
-        if not (touch_member(config, dcs) and dcs.attempt_to_acquire_leader(permanent=True)):
-            # we did initialize this cluster, but failed to write the leader or member keys, wipe it down completely.
-            raise PatroniCtlException("Unable to install permanent leader for cluster {0}".format(cluster_name))
-    except:
-        raise
+    # make sure the leader keys will never expire
+    if not (touch_member(config, dcs) and dcs.attempt_to_acquire_leader(permanent=True)):
+        # we did initialize this cluster, but failed to write the leader or member keys, wipe it down completely.
+        dcs.delete_cluster()
+        raise PatroniCtlException("Unable to install permanent leader for cluster {0}".format(cluster_name))
     click.echo("Cluster {0} has been created successfully".format(cluster_name))

patroni/dcs/__init__.py

@@ -316,7 +316,7 @@ class AbstractDCS(object):
     def attempt_to_acquire_leader(self, permanent=False):
         """Attempt to acquire leader lock
         This method should create `/leader` key with value=`~self._name`
-        :param permanent: if set to `!True`, the leader key will never expie. Used in patronictl for the external master
+        :param permanent: if set to `!True`, the leader key will never expire. Used in patronictl for the external master
         :returns: `!True` if key has been created successfully.
 
         Key must be created atomically. In case if key already exists it should not be

tests/test_ctl.py

@@ -10,8 +10,7 @@ from six.moves import BaseHTTPServer
 from click.testing import CliRunner
 from mock import patch, Mock
 from patroni.ctl import ctl, members, store_config, load_config, output_members, post_patroni, get_dcs, parse_dcs, \
-    wait_for_leader, get_all_members, get_any_member, get_cursor, query_member, configure, touch_member, set_defaults,\
-    PatroniCtlException
+    wait_for_leader, get_all_members, get_any_member, get_cursor, query_member, configure, PatroniCtlException
 
 from patroni.exceptions import DCSError
 from psycopg2 import OperationalError
@@ -316,9 +315,9 @@ class TestCtl(unittest.TestCase):
 
         with patch.object(self.e, 'initialize', return_value=False):
             result = self.runner.invoke(ctl, ['scaffold', 'alpha'])
-            assert result.exit_code == 1
+            assert result.exception
 
-        with patch.object(mock_get_dcs.return_value, 'touch_member', Mock(side_effect=DCSError("foo"))):
+        with patch.object(mock_get_dcs.return_value, 'touch_member', Mock(return_value=False)):
             result = self.runner.invoke(ctl, ['scaffold', 'alpha'])
             assert result.exception
 
@@ -327,4 +326,4 @@ class TestCtl(unittest.TestCase):
 
         mock_get_dcs.return_value.get_cluster = get_cluster_initialized_with_leader
         result = self.runner.invoke(ctl, ['scaffold', 'alpha'])
-        assert result.exit_code == 1
+        assert result.exception