Add an on-demand single-target sync method

- Adds `target_sync`, a method invoked only via RPC (probably)
by an admin API call. That somewhat intelligently replays all
the changes from a specific timestamp (serial #) on a given target.
- This came about from the following situation:
I run N number of nameservers, and I don't want all my zones going
to ERROR if I have to take one out of rotation of an emergency.
I want to be able to set my threshold percentage at N-1/100,
and sync back up all the changes that have happened while I was
doing maintenance. Unfortunately, Designate's periodic_recovery,
nor periodic_sync would work well for this method. Recovery only
fixes ERRORs, and sync simply sends NOTIFYs (and is too deeply
entombed in spaghetti code to be dug out) and is run automatically
on a set time interval, for a specific number of seconds, for all
targets.
- Includes a very simple Admin API call that looks like:
```json
POST /admin/target_sync

{
    "target_id": "f02a0c72-c701-4ec2-85d7-197b30992ce9",
    "timestamp": 1454071711
}

{
    "message": "Syncing 79 zones on f02a0c72-c701-4ec2-85d7-197b30992ce9"
}
```

Change-Id: I3e3b608049a67b2258cd05d208af46f19df8cbdb

designate/api/admin/controllers/extensions/target_sync.py

@@ -0,0 +1,54 @@
+# COPYRIGHT 2015 Rackspace Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import pecan
+from oslo_log import log as logging
+from oslo_config import cfg
+
+from designate.api.v2.controllers import rest
+from designate import exceptions
+
+LOG = logging.getLogger(__name__)
+CONF = cfg.CONF
+
+
+class TargetSyncController(rest.RestController):
+
+    @staticmethod
+    def get_path():
+        return '.target_sync'
+
+    @pecan.expose(template='json:', content_type='application/json')
+    def post_all(self):
+        """Initialize a Target Syncing"""
+        request = pecan.request
+        context = request.environ['context']
+
+        body = request.body_dict
+
+        fields = ['target_id', 'timestamp']
+        for f in fields:
+            if f not in body:
+                raise exceptions.BadRequest('Failed to supply correct fields')
+
+        if (not isinstance(body['timestamp'], int) or body['timestamp'] < 0):
+            raise exceptions.BadRequest(
+                'Timestamp should be a positive integer')
+
+        pool_id = CONF['service:pool_manager'].pool_id
+
+        return {
+            'message': self.pool_mgr_api.target_sync(context, pool_id,
+            body['target_id'], body['timestamp'])
+        }

designate/api/admin/controllers/root.py

@@ -16,6 +16,7 @@
 from oslo_log import log as logging
 from stevedore import named
 
+from designate.i18n import _LI
 from designate.api.v2.controllers import errors
 
 
@@ -38,6 +39,7 @@ def __init__(self):
             for ext in self._mgr:
                 controller = self
                 path = ext.obj.get_path()
+                LOG.info(_LI("Registering an API extension at path %s"), path)
                 for p in path.split('.')[:-1]:
                     if p != '':
                         controller = getattr(controller, p)

designate/api/v2/controllers/rest.py

@@ -33,6 +33,7 @@
 
 from designate import exceptions
 from designate.central import rpcapi as central_rpcapi
+from designate.pool_manager import rpcapi as pool_mgr_rpcapi
 from designate.zone_manager import rpcapi as zone_manager_rpcapi
 from designate.i18n import _
 
@@ -55,6 +56,10 @@ class RestController(pecan.rest.RestController):
     def central_api(self):
         return central_rpcapi.CentralAPI.get_instance()
 
+    @property
+    def pool_mgr_api(self):
+        return pool_mgr_rpcapi.PoolManagerAPI.get_instance()
+
     @property
     def zone_manager_api(self):
         return zone_manager_rpcapi.ZoneManagerAPI.get_instance()

designate/pool_manager/rpcapi.py

@@ -36,15 +36,16 @@ class PoolManagerAPI(object):
 
         1.0 - Initial version
         2.0 - Rename domains to zones
+        2.1 - Add target_sync
     """
-    RPC_API_VERSION = '2.0'
+    RPC_API_VERSION = '2.1'
 
     def __init__(self, topic=None):
         self.topic = topic if topic else cfg.CONF.pool_manager_topic
 
         target = messaging.Target(topic=self.topic,
                                   version=self.RPC_API_VERSION)
-        self.client = rpc.get_client(target, version_cap='2.0')
+        self.client = rpc.get_client(target, version_cap='2.1')
 
     @classmethod
     def get_instance(cls):
@@ -60,6 +61,18 @@ def get_instance(cls):
             MNGR_API = cls()
         return MNGR_API
 
+    def target_sync(self, context, pool_id, target_id, timestamp):
+        LOG.info(_LI("target_sync: Syncing target %(target) since "
+                     "%(timestamp)d."),
+            {'target': target_id, 'timestamp': timestamp})
+
+        # Modifying the topic so it is pool manager instance specific.
+        topic = '%s.%s' % (self.topic, pool_id)
+        cctxt = self.client.prepare(topic=topic)
+        return cctxt.call(
+            context, 'target_sync', pool_id=pool_id, target_id=target_id,
+            timestamp=timestamp)
+
     def create_zone(self, context, zone):
         LOG.info(_LI("create_zone: Calling pool manager for %(zone)s, "
                      "serial:%(serial)s"),

designate/pool_manager/service.py

@@ -16,6 +16,7 @@
 from contextlib import contextmanager
 from decimal import Decimal
 import time
+from datetime import datetime
 
 from oslo_config import cfg
 import oslo_messaging as messaging
@@ -86,8 +87,10 @@ class Service(service.RPCService, coordination.CoordinationMixin,
     API version history:
 
         1.0 - Initial version
+        2.0 - The Big Rename
+        2.1 - Add target_sync
     """
-    RPC_API_VERSION = '2.0'
+    RPC_API_VERSION = '2.1'
 
     target = messaging.Target(version=RPC_API_VERSION)
 
@@ -276,6 +279,79 @@ def periodic_sync(self):
             self.central_api.update_status(context, zone.id, ERROR_STATUS,
                                            zone.serial)
 
+    def target_sync(self, context, pool_id, target_id, timestamp):
+        """
+        Replay all the events that we can since a certain timestamp
+        """
+        context = self._get_admin_context_all_tenants()
+        context.show_deleted = True
+
+        target = None
+        for tar in self.pool.targets:
+            if tar.id == target_id:
+                target = tar
+        if target is None:
+            raise exceptions.BadRequest('Please supply a valid target id.')
+
+        LOG.info(_LI('Starting Target Sync'))
+
+        criterion = {
+            'pool_id': pool_id,
+            'updated_at': '>%s' % datetime.fromtimestamp(timestamp).
+            isoformat(),
+        }
+
+        zones = self.central_api.find_zones(context, criterion=criterion,
+            sort_key='updated_at', sort_dir='asc')
+
+        self.tg.add_thread(self._target_sync,
+            context, zones, target, timestamp)
+
+        return 'Syncing %(len)s zones on %(target)s' % {'len': len(zones),
+                                                        'target': target_id}
+
+    def _target_sync(self, context, zones, target, timestamp):
+        zone_ops = []
+        timestamp_dt = datetime.fromtimestamp(timestamp)
+
+        for zone in zones:
+            if zone.status == 'DELETED':
+                # Remove any other ops for this zone
+                for zone_op in zone_ops:
+                    if zone.name == zone_op[0].name:
+                        zone_ops.remove(zone_op)
+                # If the zone was created before the timestamp delete it,
+                # otherwise, it will just never be created
+                if (datetime.strptime(zone.created_at, "%Y-%m-%dT%H:%M:%S.%f")
+                        <= timestamp_dt):
+                    zone_ops.append((zone, 'DELETE'))
+            elif (datetime.strptime(zone.created_at, "%Y-%m-%dT%H:%M:%S.%f") >
+                  timestamp_dt):
+                # If the zone was created after the timestamp
+                for zone_op in zone_ops:
+                    if (
+                        zone.name == zone_op[0].name and
+                        zone_op[1] == 'DELETE'
+                    ):
+                        zone_ops.remove(zone_op)
+
+                zone_ops.append((zone, 'CREATE'))
+            else:
+                zone_ops.append((zone, 'UPDATE'))
+
+        for zone, action in zone_ops:
+            if action == 'CREATE':
+                self._create_zone_on_target(context, target, zone)
+            elif action == 'UPDATE':
+                self._update_zone_on_target(context, target, zone)
+            elif action == 'DELETE':
+                self._delete_zone_on_target(context, target, zone)
+                zone.serial = 0
+            for nameserver in self.pool.nameservers:
+                self.mdns_api.poll_for_serial_number(
+                    context, zone, nameserver, self.timeout,
+                    self.retry_interval, self.max_retries, self.delay)
+
     # Standard Create/Update/Delete Methods
 
     def create_zone(self, context, zone):

etc/designate/designate.conf.sample

@@ -134,7 +134,7 @@ debug = False
 #enable_api_admin = False
 
 # Enabled Admin API extensions
-# Can be one or more of : reports, quotas, counts, tenants, zones
+# Can be one or more of : reports, quotas, counts, tenants, target_sync
 # zone export is in zones extension
 #enabled_extensions_admin =
 

setup.cfg

@@ -64,6 +64,7 @@ designate.api.admin.extensions =
     reports = designate.api.admin.controllers.extensions.reports:ReportsController
     quotas = designate.api.admin.controllers.extensions.quotas:QuotasController
     zones = designate.api.admin.controllers.extensions.zones:ZonesController
+    target_sync = designate.api.admin.controllers.extensions.target_sync:TargetSyncController
 
 designate.storage =
     sqlalchemy = designate.storage.impl_sqlalchemy:SQLAlchemyStorage