Add support for notifications with zmq

charm-helpers-hooks.yaml

@@ -1,4 +1,4 @@
-branch: lp:charm-helpers
+branch: lp:~openstack-charmers/charm-helpers/0mq
 destination: hooks/charmhelpers
 include:
     - core

hooks/charmhelpers/contrib/openstack/context.py

@@ -21,6 +21,7 @@ from charmhelpers.core.hookenv import (
     relation_get,
     relation_ids,
     related_units,
+    is_relation_made,
     relation_set,
     unit_get,
     unit_private_ip,
@@ -49,6 +50,9 @@ from charmhelpers.contrib.network.ip import (
     get_ipv6_addr,
 )
 
+from charmhelpers.contrib.openstack.utils import (
+    get_matchmaker_map,
+)
 CA_CERT_PATH = '/usr/local/share/ca-certificates/keystone_juju_ca_cert.crt'
 
 
@@ -787,3 +791,37 @@ class SyslogContext(OSContextGenerator):
             'use_syslog': config('use-syslog')
         }
         return ctxt
+
+
+class ZeroMQContext(OSContextGenerator):
+    interfaces = ['zeromq-configuration']
+
+    def __call__(self):
+        ctxt = {}
+        if is_relation_made('zeromq-configuration', 'host'):
+            for rid in relation_ids('zeromq-configuration'):
+                    for unit in related_units(rid):
+                        ctxt['zmq_nonce'] = relation_get('nonce', unit, rid)
+                        ctxt['zmq_host'] = relation_get('host', unit, rid)
+        return ctxt
+
+class NotificationDriverContext(OSContextGenerator):
+
+    def __init__(self, zmq_relation='zeromq-configuration', amqp_relation='amqp'):
+        """
+        :param zmq_relation   : Name of Zeromq relation to check
+        """
+        self.zmq_relation = zmq_relation
+        self.amqp_relation = amqp_relation
+
+    def __call__(self):
+        ctxt = {
+            'notifications': "False",
+        }
+        if is_relation_made(self.zmq_relation):
+            matchmaker_data = get_matchmaker_map()
+            if 'notifications-info' in matchmaker_data:
+                ctxt['notifications'] = "True"
+        elif is_relation_made(self.amqp_relation):
+            ctxt['notifications'] = "True"
+        return ctxt

hooks/charmhelpers/contrib/openstack/utils.py

@@ -3,15 +3,17 @@
 # Common python helper functions used for OpenStack charms.
 from collections import OrderedDict
 
-import subprocess
+import json
 import os
 import socket
+import subprocess
 import sys
 
 from charmhelpers.core.hookenv import (
     config,
     log as juju_log,
     charm_dir,
+    is_relation_made,
     ERROR,
     INFO
 )
@@ -70,6 +72,7 @@ SWIFT_CODENAMES = OrderedDict([
     ('1.13.0', 'icehouse'),
     ('1.12.0', 'icehouse'),
     ('1.11.0', 'icehouse'),
+    ('2.0.0', 'juno'),
 ])
 
 DEFAULT_LOOPBACK_SIZE = '5G'
@@ -456,3 +459,11 @@ def get_hostname(address, fqdn=True):
             return result
     else:
         return result.split('.')[0]
+
+
+def get_matchmaker_map(mm_file='/etc/oslo/matchmaker_ring.json'):
+    mm_map = {}
+    if os.path.isfile(mm_file):
+        with open(mm_file, 'r') as f:
+            mm_map = json.load(f)
+    return mm_map

hooks/charmhelpers/core/hookenv.py

@@ -156,12 +156,15 @@ def hook_name():
 
 
 class Config(dict):
-    """A Juju charm config dictionary that can write itself to
-    disk (as json) and track which values have changed since
-    the previous hook invocation.
+    """A dictionary representation of the charm's config.yaml, with some
+    extra features:
 
-    Do not instantiate this object directly - instead call
-    ``hookenv.config()``
+    - See which values in the dictionary have changed since the previous hook.
+    - For values that have changed, see what the previous value was.
+    - Store arbitrary data for use in a later hook.
+
+    NOTE: Do not instantiate this object directly - instead call
+    ``hookenv.config()``, which will return an instance of :class:`Config`.
 
     Example usage::
 
@@ -170,8 +173,8 @@ class Config(dict):
         >>> config = hookenv.config()
         >>> config['foo']
         'bar'
+        >>> # store a new key/value for later use
         >>> config['mykey'] = 'myval'
-        >>> config.save()
 
 
         >>> # user runs `juju set mycharm foo=baz`
@@ -188,22 +191,23 @@ class Config(dict):
         >>> # keys/values that we add are preserved across hooks
         >>> config['mykey']
         'myval'
-        >>> # don't forget to save at the end of hook!
-        >>> config.save()
 
     """
     CONFIG_FILE_NAME = '.juju-persistent-config'
 
     def __init__(self, *args, **kw):
         super(Config, self).__init__(*args, **kw)
+        self.implicit_save = True
         self._prev_dict = None
         self.path = os.path.join(charm_dir(), Config.CONFIG_FILE_NAME)
         if os.path.exists(self.path):
             self.load_previous()
 
     def load_previous(self, path=None):
-        """Load previous copy of config from disk so that current values
-        can be compared to previous values.
+        """Load previous copy of config from disk.
+
+        In normal usage you don't need to call this method directly - it
+        is called automatically at object initialization.
 
         :param path:
 
@@ -218,8 +222,8 @@ class Config(dict):
             self._prev_dict = json.load(f)
 
     def changed(self, key):
-        """Return true if the value for this key has changed since
-        the last save.
+        """Return True if the current value for this key is different from
+        the previous value.
 
         """
         if self._prev_dict is None:
@@ -228,7 +232,7 @@ class Config(dict):
 
     def previous(self, key):
         """Return previous value for this key, or None if there
-        is no "previous" value.
+        is no previous value.
 
         """
         if self._prev_dict:
@@ -238,7 +242,13 @@ class Config(dict):
     def save(self):
         """Save this config to disk.
 
-        Preserves items in _prev_dict that do not exist in self.
+        If the charm is using the :mod:`Services Framework <services.base>`
+        or :meth:'@hook <Hooks.hook>' decorator, this
+        is called automatically at the end of successful hook execution.
+        Otherwise, it should be called directly by user code.
+
+        To disable automatic saves, set ``implicit_save=False`` on this
+        instance.
 
         """
         if self._prev_dict:
@@ -478,6 +488,9 @@ class Hooks(object):
         hook_name = os.path.basename(args[0])
         if hook_name in self._hooks:
             self._hooks[hook_name]()
+            cfg = config()
+            if cfg.implicit_save:
+                cfg.save()
         else:
             raise UnregisteredHookError(hook_name)
 

hooks/charmhelpers/core/services/base.py

@@ -118,6 +118,9 @@ class ServiceManager(object):
         else:
             self.provide_data()
             self.reconfigure_services()
+        cfg = hookenv.config()
+        if cfg.implicit_save:
+            cfg.save()
 
     def provide_data(self):
         """

hooks/glance_utils.py

@@ -92,7 +92,9 @@ CONFIG_FILES = OrderedDict([
                           glance_contexts.ObjectStoreContext(),
                           glance_contexts.HAProxyContext(),
                           context.SyslogContext(),
-                          glance_contexts.LoggingConfigContext()],
+                          glance_contexts.LoggingConfigContext(),
+                          context.ZeroMQContext(),
+                          context.NotificationDriverContext(),],
         'services': ['glance-api']
     }),
     (GLANCE_API_PASTE_INI, {

metadata.yaml

@@ -27,6 +27,9 @@ requires:
   ha:
     interface: hacluster
     scope: container
+  zeromq-configuration:
+    interface: zeromq-configuration
+    scope: container
 peers:
   cluster:
     interface: glance-ha

templates/icehouse/glance-api.conf

@@ -32,9 +32,7 @@ registry_client_protocol = http
 
 {% include "parts/rabbitmq" %}
 
-{% if rabbitmq_host or rabbitmq_hosts -%}
-notification_driver = rabbit
-{% endif -%}
+{% include "parts/zeromq" %}
 
 filesystem_store_datadir = /var/lib/glance/images/
 

templates/parts/rabbitmq

@@ -18,4 +18,6 @@ rabbit_port = {{ rabbit_ssl_port }}
 kombu_ssl_ca_certs = {{ rabbit_ssl_ca }}
 {% endif -%}
 {% endif -%}
-{% endif -%}
+{% if notifications == 'True' -%}                                                                                                                notification_driver = rabbit                                                                                                                     
+{% endif -%} 
+{% endif -%}

templates/parts/zeromq

@@ -0,0 +1,9 @@
+{% if zmq_host -%}
+# ZeroMQ configuration (restart-nonce: {{ zmq_nonce }})
+rpc_backend = zmq
+rpc_zmq_matchmaker = oslo.messaging._drivers.matchmaker_ring.MatchMakerRing
+rpc_zmq_host = {{ zmq_host }}
+{% if notifications == 'True' -%}
+notification_driver = zmq
+{% endif -%}
+{% endif -%}