[trivial] charm-helpers sync

hooks/charmhelpers/core/hookenv.py

@@ -28,7 +28,6 @@ import yaml
 import subprocess
 import sys
 import errno
-import tempfile
 from subprocess import CalledProcessError
 
 import six
@@ -363,33 +362,29 @@ def relation_set(relation_id=None, relation_settings=None, **kwargs):
     """Set relation information for the current unit"""
     relation_settings = relation_settings if relation_settings else {}
     relation_cmd_line = ['relation-set']
-    accepts_file = "--file" in subprocess.check_output(
-        relation_cmd_line + ["--help"])
     if relation_id is not None:
         relation_cmd_line.extend(('-r', relation_id))
-    settings = relation_settings.copy()
+    for k, v in (list(relation_settings.items()) + list(kwargs.items())):
-    settings.update(kwargs)
+        if v is None:
-    if accepts_file:
+            relation_cmd_line.append('{}='.format(k))
-        # --file was introduced in Juju 1.23.2. Use it by default if
+        else:
-        # available, since otherwise we'll break if the relation data is
+            relation_cmd_line.append('{}={}'.format(k, v))
-        # too big. Ideally we should tell relation-set to read the data from
+    subprocess.check_call(relation_cmd_line)
-        # stdin, but that feature is broken in 1.23.2: Bug #1454678.
-        with tempfile.NamedTemporaryFile(delete=False) as settings_file:
-            settings_file.write(yaml.safe_dump(settings).encode("utf-8"))
-        subprocess.check_call(
-            relation_cmd_line + ["--file", settings_file.name])
-        os.remove(settings_file.name)
-    else:
-        for key, value in settings.items():
-            if value is None:
-                relation_cmd_line.append('{}='.format(key))
-            else:
-                relation_cmd_line.append('{}={}'.format(key, value))
-        subprocess.check_call(relation_cmd_line)
     # Flush cache of any relation-gets for local unit
     flush(local_unit())
 
 
+def relation_clear(r_id=None):
+    ''' Clears any relation data already set on relation r_id '''
+    settings = relation_get(rid=r_id,
+                            unit=local_unit())
+    for setting in settings:
+        if setting not in ['public-address', 'private-address']:
+            settings[setting] = None
+    relation_set(relation_id=r_id,
+                 **settings)
+
+
 @cached
 def relation_ids(reltype=None):
     """A list of relation_ids"""
@@ -681,3 +676,48 @@ def status_get():
             return 'unknown'
         else:
             raise
+
+
+def translate_exc(from_exc, to_exc):
+    def inner_translate_exc1(f):
+        def inner_translate_exc2(*args, **kwargs):
+            try:
+                return f(*args, **kwargs)
+            except from_exc:
+                raise to_exc
+
+        return inner_translate_exc2
+
+    return inner_translate_exc1
+
+
+@translate_exc(from_exc=OSError, to_exc=NotImplementedError)
+def is_leader():
+    """Does the current unit hold the juju leadership
+
+    Uses juju to determine whether the current unit is the leader of its peers
+    """
+    cmd = ['is-leader', '--format=json']
+    return json.loads(subprocess.check_output(cmd).decode('UTF-8'))
+
+
+@translate_exc(from_exc=OSError, to_exc=NotImplementedError)
+def leader_get(attribute=None):
+    """Juju leader get value(s)"""
+    cmd = ['leader-get', '--format=json'] + [attribute or '-']
+    return json.loads(subprocess.check_output(cmd).decode('UTF-8'))
+
+
+@translate_exc(from_exc=OSError, to_exc=NotImplementedError)
+def leader_set(settings=None, **kwargs):
+    """Juju leader set value(s)"""
+    log("Juju leader-set '%s'" % (settings), level=DEBUG)
+    cmd = ['leader-set']
+    settings = settings or {}
+    settings.update(kwargs)
+    for k, v in settings.iteritems():
+        if v is None:
+            cmd.append('{}='.format(k))
+        else:
+            cmd.append('{}={}'.format(k, v))
+    subprocess.check_call(cmd)

hooks/charmhelpers/core/services/base.py

@@ -15,8 +15,8 @@
 # along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
 
 import os
-import re
 import json
+from inspect import getargspec
 from collections import Iterable, OrderedDict
 
 from charmhelpers.core import host
@@ -132,8 +132,8 @@ class ServiceManager(object):
         if hook_name == 'stop':
             self.stop_services()
         else:
-            self.provide_data()
             self.reconfigure_services()
+            self.provide_data()
         cfg = hookenv.config()
         if cfg.implicit_save:
             cfg.save()
@@ -145,15 +145,36 @@ class ServiceManager(object):
         A provider must have a `name` attribute, which indicates which relation
         to set data on, and a `provide_data()` method, which returns a dict of
         data to set.
+
+        The `provide_data()` method can optionally accept two parameters:
+
+          * ``remote_service`` The name of the remote service that the data will
+            be provided to.  The `provide_data()` method will be called once
+            for each connected service (not unit).  This allows the method to
+            tailor its data to the given service.
+          * ``service_ready`` Whether or not the service definition had all of
+            its requirements met, and thus the ``data_ready`` callbacks run.
+
+        Note that the ``provided_data`` methods are now called **after** the
+        ``data_ready`` callbacks are run.  This gives the ``data_ready`` callbacks
+        a chance to generate any data necessary for the providing to the remote
+        services.
         """
-        hook_name = hookenv.hook_name()
+        for service_name, service in self.services.items():
-        for service in self.services.values():
+            service_ready = self.is_ready(service_name)
             for provider in service.get('provided_data', []):
-                if re.match(r'{}-relation-(joined|changed)'.format(provider.name), hook_name):
+                for relid in hookenv.relation_ids(provider.name):
-                    data = provider.provide_data()
+                    units = hookenv.related_units(relid)
-                    _ready = provider._is_ready(data) if hasattr(provider, '_is_ready') else data
+                    if not units:
-                    if _ready:
+                        continue
-                        hookenv.relation_set(None, data)
+                    remote_service = units[0].split('/')[0]
+                    argspec = getargspec(provider.provide_data)
+                    if len(argspec.args) > 1:
+                        data = provider.provide_data(remote_service, service_ready)
+                    else:
+                        data = provider.provide_data()
+                    if data:
+                        hookenv.relation_set(relid, data)
 
     def reconfigure_services(self, *service_names):
         """