Merge lp:~stub/charm-helpers/status-set into lp:charm-helpers

[Stuart Bishop]

Wrap the new status-set and status-get hook tools, with fallback when running with versions of Juju that do not support the service status feature.

[Stuart Bishop (stub)]

The implicit termination causes trouble with the Config persistence feature, so that will need to be fixed. Or scrap this and go with https://code.launchpad.net/~gnuoy/charm-helpers/status-set/+merge/258533 which I just found.

[Stuart Bishop (stub)]

review: Disapprove

Unmerged revisions

370. By Stuart Bishop on 2015-05-08

Wrap status-set and status-get, with fallback behavior for pre-service-status Juju

=== modified file 'charmhelpers/core/hookenv.py'
--- charmhelpers/core/hookenv.py	2015-04-07 16:12:51 +0000
+++ charmhelpers/core/hookenv.py	2015-05-08 12:54:37 +0000
@@ -1,4 +1,4 @@
-# Copyright 2014-2015 Canonical Limited.
+# Copyright 2013-2015 Canonical Limited.
 #
 # This file is part of charm-helpers.
 #
@@ -13,14 +13,13 @@
 #
 # You should have received a copy of the GNU Lesser General Public License
 # along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
-
-"Interactions with the Juju environment"
-# Copyright 2013 Canonical Ltd.
 #
 # Authors:
 #  Charm Helpers Developers <[e-mail]>
+"Interactions with the Juju environment"
 
 from __future__ import print_function
+from distutils.spawn import find_executable
 import os
 import json
 import yaml
@@ -605,3 +604,68 @@
 
     The results set by action_set are preserved."""
     subprocess.check_call(['action-fail', message])
+
+
+@cached
+def _has_status_feature():
+    return find_executable('status-set') is not None
+
+
+MAINTENANCE = 'MAINTENANCE'
+BLOCKED = 'BLOCKED'
+WAITING = 'WAITING'
+ACTIVE = 'ACTIVE'
+
+
+def status_set(status, message):
+    """Sets the unit's service status. If waiting or blocked, terminate.
+
+    `status` must be one of 'maintenance', 'blocked', 'waiting' or 'active'.
+
+    If the service status feature is unavailable, logs the message and
+    puts the unit into an error state if blocked, or terminates cleanly
+    if waiting.
+
+    This API is subject to change until the Juju service status feature
+    is available in a stable release (est. Juju 1.24).
+    """
+    status = str(status).lower()
+    assert status in ('maintenance', 'blocked', 'waiting', 'active'), \
+        'Invalid status code {!r}'.format(status)
+
+    if _has_status_feature():
+        subprocess.check_call(['status-set', status, str(message)])
+        if status in ('waiting', 'blocked'):
+            sys.exit(0)  # Exit cleanly.
+    else:
+        message = '{}: {}'.format(status, message)
+        if status == 'waiting':
+            log(message, WARNING)
+            sys.exit(0)  # Exit cleanly.
+        elif status == 'blocked':
+            log(message, CRITICAL)
+            sys.exit(1)  # Exit uncleanly. Signal manual intervention required.
+        else:
+            log(message, INFO)
+
+
+def status_get():
+    """Return the unit's service status."""
+    if _has_status_feature():
+        s = subprocess.check_output(['status-get'], universal_newlines=True)
+        return s.strip()
+    else:
+        return "unknown"
+
+
+def status_get_details():
+    """Return the unit's service status and any associated data as a dict.
+
+    The format is as defined by the 'status-get --include-data' hook tool.
+    """
+    if _has_status_feature():
+        raw = subprocess.check_output(['status-get', '--include-data'],
+                                      universal_newlines=True)
+        return yaml.safe_load(raw)
+    else:
+        return {}

=== modified file 'tests/core/test_hookenv.py'
--- tests/core/test_hookenv.py	2015-03-12 10:31:22 +0000
+++ tests/core/test_hookenv.py	2015-05-08 12:54:37 +0000
@@ -1115,3 +1115,121 @@
         message = "Ooops, the action failed"
         hookenv.action_fail(message)
         check_call.assert_called_with(['action-fail', message])
+
+    @patch('charmhelpers.core.hookenv.find_executable')
+    def test_has_status_feature(self, find_executable):
+        hookenv.cache.clear()
+        find_executable.return_value = '/bin/status-set'
+        self.assertTrue(hookenv._has_status_feature())
+        find_executable.assert_called_once_with('status-set')
+        hookenv.cache.clear()
+        find_executable.return_value = None
+        self.assertFalse(hookenv._has_status_feature())
+
+    @patch('subprocess.check_call')
+    @patch('charmhelpers.core.hookenv._has_status_feature')
+    @patch('sys.exit')
+    def test_status_set_maintenance(self, exit, hasf, check_call):
+        hasf.return_value = True
+        hookenv.status_set(hookenv.MAINTENANCE, 'mincing kittens')
+        check_call.assert_called_once_with(['status-set', 'maintenance',
+                                            'mincing kittens'])
+        self.assertFalse(exit.called)
+
+    @patch('subprocess.check_call')
+    @patch('charmhelpers.core.hookenv._has_status_feature')
+    @patch('sys.exit')
+    def test_status_set_waiting(self, exit, hasf, check_call):
+        hasf.return_value = True
+        hookenv.status_set(hookenv.WAITING, 'kitten delivery')
+        check_call.assert_called_once_with(['status-set', 'waiting',
+                                            'kitten delivery'])
+        exit.assert_called_once_with(0)
+
+    @patch('subprocess.check_call')
+    @patch('charmhelpers.core.hookenv._has_status_feature')
+    @patch('sys.exit')
+    def test_status_set_blocked(self, exit, hasf, check_call):
+        hasf.return_value = True
+        hookenv.status_set(hookenv.BLOCKED, 'feed moar kittens')
+        check_call.assert_called_once_with(['status-set', 'blocked',
+                                            'feed moar kittens'])
+        exit.assert_called_once_with(0)
+
+    @patch('subprocess.check_call')
+    @patch('charmhelpers.core.hookenv._has_status_feature')
+    @patch('sys.exit')
+    def test_status_set_active(self, exit, hasf, check_call):
+        hasf.return_value = True
+        hookenv.status_set(hookenv.ACTIVE, 'serving kittens')
+        check_call.assert_called_once_with(['status-set', 'active',
+                                            'serving kittens'])
+        self.assertFalse(exit.called)
+
+    @patch('charmhelpers.core.hookenv.log')
+    @patch('charmhelpers.core.hookenv._has_status_feature')
+    @patch('sys.exit')
+    def test_status_set_maintenance_fallback(self, exit, hasf, log):
+        hasf.return_value = False
+        hookenv.status_set(hookenv.MAINTENANCE, 'mincing kittens')
+        log.assert_called_once_with('maintenance: mincing kittens',
+                                    hookenv.INFO)
+        self.assertFalse(exit.called)
+
+    @patch('charmhelpers.core.hookenv.log')
+    @patch('charmhelpers.core.hookenv._has_status_feature')
+    @patch('sys.exit')
+    def test_status_set_waiting_fallback(self, exit, hasf, log):
+        hasf.return_value = False
+        hookenv.status_set(hookenv.WAITING, 'kitten delivery')
+        log.assert_called_once_with('waiting: kitten delivery',
+                                    hookenv.WARNING)
+        exit.assert_called_once_with(0)  # No unit error state.
+
+    @patch('charmhelpers.core.hookenv.log')
+    @patch('charmhelpers.core.hookenv._has_status_feature')
+    @patch('sys.exit')
+    def test_status_set_blocked_fallback(self, exit, hasf, log):
+        hasf.return_value = False
+        hookenv.status_set(hookenv.BLOCKED, 'feed me kittens')
+        log.assert_called_once_with('blocked: feed me kittens',
+                                    hookenv.CRITICAL)
+        exit.assert_called_once_with(1)  # Force unit error state
+
+    @patch('charmhelpers.core.hookenv.log')
+    @patch('charmhelpers.core.hookenv._has_status_feature')
+    @patch('sys.exit')
+    def test_status_set_active_fallback(self, exit, hasf, log):
+        hasf.return_value = False
+        hookenv.status_set(hookenv.ACTIVE, 'serving kittens')
+        log.assert_called_once_with('active: serving kittens',
+                                    hookenv.INFO)
+        self.assertFalse(exit.called)
+
+    @patch('subprocess.check_output')
+    @patch('charmhelpers.core.hookenv._has_status_feature')
+    def test_status_get(self, hasf, check_output):
+        hasf.return_value = True
+        check_output.return_value = 'whatever'
+        self.assertEqual(hookenv.status_get(), 'whatever')
+        check_output.assert_called_once_with(['status-get'],
+                                             universal_newlines=True)
+
+    @patch('subprocess.check_output')
+    @patch('charmhelpers.core.hookenv._has_status_feature')
+    def test_status_get_details(self, hasf, check_output):
+        hasf.return_value = True
+        check_output.return_value = 'some_yaml: true'
+        self.assertEqual(hookenv.status_get_details(), dict(some_yaml=True))
+        check_output.assert_called_once_with(['status-get', '--include-data'],
+                                             universal_newlines=True)
+
+    @patch('charmhelpers.core.hookenv._has_status_feature')
+    def test_status_get_fallback(self, hasf):
+        hasf.return_value = False
+        self.assertEqual(hookenv.status_get(), 'unknown')
+
+    @patch('charmhelpers.core.hookenv._has_status_feature')
+    def test_status_get_details_fallback(self, hasf):
+        hasf.return_value = False
+        self.assertDictEqual(hookenv.status_get_details(), {})