Add a new PowerDNS backend based on MiniDNS

This is stage one of phasing out the old PowerDNS driver, as we move
through the Kilo cycle and mDNS/pools become reality, the original driver
can be removed.

Implements-Blueprint: transition-powerdns-to-mdns
Change-Id: I7a3aa0a894e2c0a4fa565e8d58cccba3644e0cac

contrib/devstack/lib/designate_plugins/backend-powerdns_mdns

@@ -0,0 +1,115 @@
+# lib/designate_plugins/backend-powerdns_mdns
+# Configure the powerdns_mdns backend
+
+# Enable with:
+# DESIGNATE_BACKEND_DRIVER=powerdns_mdns
+
+# Dependencies:
+# ``functions`` file
+# ``designate`` configuration
+
+# install_designate_backend - install any external requirements
+# configure_designate_backend - make configuration changes, including those to other services
+# init_designate_backend - initialize databases, etc.
+# start_designate_backend - start any external services
+# stop_designate_backend - stop any external services
+# cleanup_designate_backend - remove transient data and cache
+
+# Save trace setting
+DP_PDNS_MDNS_XTRACE=$(set +o | grep xtrace)
+set +o xtrace
+
+# Defaults
+# --------
+if is_fedora; then
+    POWERDNS_CFG_DIR=/etc/pdns
+else
+    POWERDNS_CFG_DIR=/etc/powerdns
+fi
+
+# Entry Points
+# ------------
+
+# install_designate_backend - install any external requirements
+function install_designate_backend {
+    if is_ubuntu; then
+        PDNS=pdns-server
+    elif is_fedora || is_suse; then
+        PDNS=pdns
+    else
+        PDNS=pdns-server
+    fi
+
+    install_package $PDNS pdns-backend-mysql
+    sudo rm -rf $POWERDNS_CFG_DIR/pdns.d
+}
+
+# configure_designate_backend - make configuration changes, including those to other services
+function configure_designate_backend {
+    iniset $DESIGNATE_CONF backend:powerdns_mdns connection `database_connection_url designate_pdns_mdns`
+    iniset $DESIGNATE_CONF backend:powerdns_mdns masters "$DESIGNATE_SERVICE_HOST:$DESIGNATE_MDNS_PORT"
+    iniset $DESIGNATE_CONF service:mdns slave_nameserver_ips_and_ports "$DESIGNATE_SERVICE_HOST:$DESIGNATE_SERVICE_PORT_DNS"
+
+    sudo tee $POWERDNS_CFG_DIR/pdns.conf > /dev/null <<EOF
+# General Config
+setgid=pdns
+setuid=pdns
+config-dir=$POWERDNS_CFG_DIR
+socket-dir=/var/run
+guardian=yes
+daemon=yes
+disable-axfr=no
+local-address=$DESIGNATE_SERVICE_HOST
+local-port=$DESIGNATE_SERVICE_PORT_DNS
+master=no
+slave=yes
+cache-ttl=0
+query-cache-ttl=0
+negquery-cache-ttl=0
+EOF
+
+    if is_service_enabled mysql; then
+        sudo tee -a $POWERDNS_CFG_DIR/pdns.conf > /dev/null <<EOF
+# Launch gmysql backend
+launch=gmysql
+
+# gmysql parameters
+gmysql-host=$DATABASE_HOST
+gmysql-user=$DATABASE_USER
+gmysql-password=$DATABASE_PASSWORD
+gmysql-dbname=designate_pdns_mdns
+gmysql-dnssec=yes
+EOF
+    else
+        die $LINENO "PowerDNS mDNS backend only supports MySQL"
+    fi
+
+    restart_service pdns
+}
+
+# init_designate_backend - initialize databases, etc.
+function init_designate_backend {
+    # (Re)create designate_pdns database
+    recreate_database designate_pdns_mdns utf8
+
+    # Init and migrate designate_pdns database
+    designate-manage powerdns-mdns sync
+}
+
+# start_designate_backend - start any external services
+function start_designate_backend {
+    start_service pdns
+}
+
+# stop_designate_backend - stop any external services
+function stop_designate_backend {
+    stop_service pdns
+}
+
+# cleanup_designate_backend - remove transient data and cache
+function cleanup_designate_backend {
+    :
+}
+
+# Restore xtrace
+$DP_PDNS_MDNS_XTRACE

designate/backend/impl_powerdns_mdns/__init__.py

@@ -0,0 +1,198 @@
+# Copyright 2014 Hewlett-Packard Development Company, L.P.
+#
+# Author: Kiall Mac Innes <kiall@hp.com>
+#
+# 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 threading
+
+from oslo.config import cfg
+from oslo.db import options
+from oslo.utils import excutils
+from sqlalchemy.sql import select
+
+from designate.openstack.common import log as logging
+from designate import exceptions
+from designate.i18n import _LC
+from designate.backend import base
+from designate.backend.impl_powerdns_mdns import tables
+from designate.sqlalchemy import session
+
+LOG = logging.getLogger(__name__)
+CONF = cfg.CONF
+
+OPTS = [
+    cfg.ListOpt('masters', help="Master servers from which to transfer from."),
+]
+
+CONF.register_group(cfg.OptGroup(
+    name='backend:powerdns_mdns',
+    title="Configuration for PowerDNS MDNS Backend"
+))
+
+CONF.register_opts(OPTS + options.database_opts, group='backend:powerdns_mdns')
+
+# Overide the default DB connection registered above, to avoid name conflicts
+# between the Designate and PowerDNS databases.
+CONF.set_default('connection', 'sqlite:///$state_path/powerdns_mdns.sqlite',
+                 group='backend:powerdns_mdns')
+
+
+def _map_col(keys, col):
+    return dict([(keys[i], col[i]) for i in range(len(keys))])
+
+
+class PowerDNSMDNSBackend(base.Backend):
+    __plugin_name__ = 'powerdns_mdns'
+
+    def __init__(self, *args, **kwargs):
+        super(PowerDNSMDNSBackend, self).__init__(*args, **kwargs)
+
+        self.local_store = threading.local()
+
+    @property
+    def session(self):
+        # NOTE: This uses a thread local store, allowing each greenthread to
+        #       have it's own session stored correctly. Without this, each
+        #       greenthread may end up using a single global session, which
+        #       leads to bad things happening.
+        global LOCAL_STORE
+
+        if not hasattr(self.local_store, 'session'):
+            self.local_store.session = session.get_session(self.name)
+
+        return self.local_store.session
+
+    def _create(self, table, values):
+        query = table.insert()
+
+        resultproxy = self.session.execute(query, values)
+
+        # Refetch the row, for generated columns etc
+        query = select([table])\
+            .where(table.c.id == resultproxy.inserted_primary_key[0])
+        resultproxy = self.session.execute(query)
+
+        return _map_col(query.columns.keys(), resultproxy.fetchone())
+
+    def _get(self, table, id_, exc_notfound, id_col=None):
+        if id_col is None:
+            id_col = table.c.id
+
+        query = select([table])\
+            .where(id_col == id_)
+
+        resultproxy = self.session.execute(query)
+
+        results = resultproxy.fetchall()
+
+        if len(results) != 1:
+            raise exc_notfound()
+
+        # Map col keys to values in result
+        return _map_col(query.columns.keys(), results[0])
+
+    def _delete(self, table, id_, exc_notfound, id_col=None):
+        if id_col is None:
+            id_col = table.c.id
+
+        query = table.delete()\
+            .where(id_col == id_)
+
+        resultproxy = self.session.execute(query)
+
+        if resultproxy.rowcount != 1:
+            raise exc_notfound()
+
+    def create_tsigkey(self, context, tsigkey):
+        pass
+
+    def update_tsigkey(self, context, tsigkey):
+        pass
+
+    def delete_tsigkey(self, context, tsigkey):
+        pass
+
+    def create_server(self, context, server):
+        pass
+
+    def update_server(self, context, server):
+        pass
+
+    def delete_server(self, context, server):
+        pass
+
+    # Domain Methods
+    def create_domain(self, context, domain):
+        try:
+            self.session.begin()
+
+            domain_values = {
+                'designate_id': domain['id'],
+                'name': domain['name'].rstrip('.'),
+                'master': ','.join(CONF['backend:powerdns_mdns'].masters),
+                'type': 'SLAVE',
+                'account': context.tenant
+            }
+
+            self._create(tables.domains, domain_values)
+        except Exception:
+            with excutils.save_and_reraise_exception():
+                self.session.rollback()
+        else:
+            self.session.commit()
+
+    def update_domain(self, context, domain):
+        pass
+
+    def delete_domain(self, context, domain):
+        try:
+            self._get(tables.domains, domain['id'], exceptions.DomainNotFound,
+                      id_col=tables.domains.c.designate_id)
+        except exceptions.DomainNotFound:
+            # If the Domain is already gone, that's ok. We're deleting it
+            # anyway, so just log and continue.
+            LOG.critical(_LC('Attempted to delete a domain which is '
+                             'not present in the backend. ID: %s') %
+                         domain['id'])
+            return
+
+        self._delete(tables.domains, domain['id'],
+                     exceptions.DomainNotFound,
+                     id_col=tables.domains.c.designate_id)
+
+    def create_recordset(self, context, domain, recordset):
+        pass
+
+    def update_recordset(self, context, domain, recordset):
+        pass
+
+    def delete_recordset(self, context, domain, recordset):
+        pass
+
+    def create_record(self, context, domain, recordset, record):
+        pass
+
+    def update_record(self, context, domain, recordset, record):
+        pass
+
+    def delete_record(self, context, domain, recordset, record):
+        pass
+
+    def sync_domain(self, context, domain, records):
+        pass
+
+    def sync_record(self, context, domain, record):
+        pass
+
+    def ping(self, context):
+        pass

designate/backend/impl_powerdns_mdns/tables.py

@@ -0,0 +1,23 @@
+# Copyright 2012-2014 Hewlett-Packard Development Company, L.P.
+#
+# Author: Kiall Mac Innes <kiall@hp.com>
+#
+# 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.
+from designate.backend.impl_powerdns import tables
+
+
+# NOTE(kiall): We import the domains table object here in order to ensure
+#              the PowerDNS mDNS based driver uses only this one table. When
+#              the original PowerDNS driver is removed, we'll move the domains
+#              table definition here.
+domains = tables.domains

designate/manage/powerdns_mdns.py

@@ -0,0 +1,59 @@
+# Copyright 2014 Hewlett-Packard Development Company, L.P.
+#
+# Author: Kiall Mac Innes <kiall@hp.com>
+#
+# 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 os
+
+from migrate.versioning import api as versioning_api
+from oslo.config import cfg
+from oslo.db.sqlalchemy.migration_cli import manager as migration_manager
+
+from designate.openstack.common import log as logging
+from designate.manage import base
+
+
+LOG = logging.getLogger(__name__)
+
+REPOSITORY = os.path.abspath(os.path.join(os.path.dirname(__file__), '..',
+                                          'backend', 'impl_powerdns',
+                                          'migrate_repo'))
+cfg.CONF.import_opt('connection', 'designate.backend.impl_powerdns_mdns',
+                    group='backend:powerdns_mdns')
+
+CONF = cfg.CONF
+
+
+def get_manager():
+    migration_config = {
+        'migration_repo_path': REPOSITORY,
+        'db_url': CONF['backend:powerdns_mdns'].connection}
+    return migration_manager.MigrationManager(migration_config)
+
+
+class DatabaseCommands(base.Commands):
+    def version(self):
+        current = get_manager().version()
+        latest = versioning_api.version(repository=REPOSITORY).value
+        print("Current: %s Latest: %s" % (current, latest))
+
+    def sync(self):
+        get_manager().upgrade(None)
+
+    @base.args('revision', nargs='?')
+    def upgrade(self, revision):
+        get_manager().upgrade(revision)
+
+    @base.args('revision', nargs='?')
+    def downgrade(self, revision):
+        get_manager().downgrade(revision)

setup.cfg

@@ -66,6 +66,7 @@ designate.notification.handler =
 designate.backend =
     bind9 = designate.backend.impl_bind9:Bind9Backend
     powerdns = designate.backend.impl_powerdns:PowerDNSBackend
+    powerdns_mdns = designate.backend.impl_powerdns_mdns:PowerDNSMDNSBackend
     rpc = designate.backend.impl_rpc:RPCBackend
     fake = designate.backend.impl_fake:FakeBackend
     nsd4slave = designate.backend.impl_nsd4slave:NSD4SlaveBackend
@@ -84,6 +85,7 @@ designate.quota =
 designate.manage =
     database = designate.manage.database:DatabaseCommands
     powerdns = designate.manage.powerdns:DatabaseCommands
+    powerdns-mdns = designate.manage.powerdns_mdns:DatabaseCommands
     tlds = designate.manage.tlds:TLDCommands