Adds network model and network info cache.

The next merge will prepopulate the cache, and use the model to keep the
cache up to date.
I realize "cache" is a bit of a stretch for what this is doing.

blueprint network-info-model
blueprint compute-network-info

Change-Id: I0f0f4ba3de1310e1ff89239dab6ea8e24c85f2c8

4 files changed, 196 insertions, 0 deletions

diff --git a/nova/db/api.py b/nova/db/api.py
index 4af79b13c..bc413319e 100644
--- a/nova/db/api.py
+++ b/nova/db/api.py
@@ -649,6 +649,48 @@ def instance_get_id_to_uuid_mapping(context, ids):
 ###################
 
 
+def instance_info_cache_create(context, values):
+    """Create a new instance cache record in the table.
+
+    :param context: = request context object
+    :param values: = dict containing column values
+    """
+    return IMPL.instance_info_cache_create(context, values)
+
+
+def instance_info_cache_get(context, instance_id, session=None):
+    """Gets an instance info cache from the table.
+
+    :param instance_id: = id of the info cache's instance
+    :param session: = optional session object
+    """
+    return IMPL.instance_info_cache_get(context, instance_id, session=None)
+
+
+def instance_info_cache_update(context, instance_id, values,
+                               session=None):
+    """Update an instance info cache record in the table.
+
+    :param instance_id: = id of info cache's instance
+    :param values: = dict containing column values to update
+    """
+    return IMPL.instance_info_cache_update(context, instance_id, values,
+                                           session)
+
+
+def instance_info_cache_delete_by_instance_id(context, instance_id,
+                                              session=None):
+    """Deletes an existing instance_info_cache record
+
+    :param instance_id: = id of the instance tied to the cache record
+    """
+    return IMPL.instance_info_cache_delete_by_instance_id(context, instance_id,
+                                                          session)
+
+
+###################
+
+
 def key_pair_create(context, values):
     """Create a key_pair from the values dictionary."""
     return IMPL.key_pair_create(context, values)
diff --git a/nova/db/sqlalchemy/api.py b/nova/db/sqlalchemy/api.py
index a8424686f..2619c247f 100644
--- a/nova/db/sqlalchemy/api.py
+++ b/nova/db/sqlalchemy/api.py
@@ -1132,6 +1132,8 @@ def instance_destroy(context, instance_id):
                 update({'deleted': True,
                         'deleted_at': utils.utcnow(),
                         'updated_at': literal_column('updated_at')})
+        instance_info_cache_delete_by_instance_id(context, instance_id,
+                                                  session=session)
 
 
 @require_context
@@ -1558,6 +1560,75 @@ def instance_get_id_to_uuid_mapping(context, ids):
 
 
 @require_context
+def instance_info_cache_create(context, values):
+    """Create a new instance cache record in the table.
+
+    :param context: = request context object
+    :param values: = dict containing column values
+    """
+    info_cache = models.InstanceInfoCache()
+    info_cache['id'] = str(utils.gen_uuid())
+    info_cache.update(values)
+
+    session = get_session()
+    with session.begin():
+        info_cache.save(session=session)
+    return info_cache
+
+
+@require_context
+def instance_info_cache_get(context, instance_id, session=None):
+    """Gets an instance info cache from the table.
+
+    :param instance_id: = id of the info cache's instance
+    :param session: = optional session object
+    """
+    session = session or get_session()
+
+    info_cache = session.query(models.InstanceInfoCache).\
+                         filter_by(instance_id=instance_id).\
+                         first()
+    return info_cache
+
+
+@require_context
+def instance_info_cache_update(context, instance_id, values,
+                               session=None):
+    """Update an instance info cache record in the table.
+
+    :param instance_id: = id of info cache's instance
+    :param values: = dict containing column values to update
+    :param session: = optional session object
+    """
+    session = session or get_session()
+    info_cache = instance_info_cache_get(context, instance_id,
+                                         session=session)
+
+    values['updated_at'] = literal_column('updated_at')
+
+    if info_cache:
+        info_cache.update(values)
+        info_cache.save(session=session)
+    return info_cache
+
+
+@require_context
+def instance_info_cache_delete_by_instance_id(context, instance_id,
+                                              session=None):
+    """Deletes an existing instance_info_cache record
+
+    :param instance_id: = id of the instance tied to the cache record
+    :param session: = optional session object
+    """
+    values = {'deleted': True,
+              'deleted_at': utils.utcnow()}
+    instance_info_cache_update(context, instance_id, values, session)
+
+
+###################
+
+
+@require_context
 def key_pair_create(context, values):
     key_pair_ref = models.KeyPair()
     key_pair_ref.update(values)
diff --git a/nova/db/sqlalchemy/migrate_repo/versions/062_add_instance_info_cache_table.py b/nova/db/sqlalchemy/migrate_repo/versions/062_add_instance_info_cache_table.py
new file mode 100644
index 000000000..99479bbf9
--- /dev/null
+++ b/nova/db/sqlalchemy/migrate_repo/versions/062_add_instance_info_cache_table.py
@@ -0,0 +1,62 @@
+# Copyright 2011 OpenStack LLC.
+# All Rights Reserved.
+#
+#    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 datetime
+
+from sqlalchemy import *
+from migrate import *
+
+from nova import log as logging
+from nova import utils
+
+meta = MetaData()
+
+# instance info cache table to add to DB
+instance_info_caches = Table('instance_info_caches', meta,
+        Column('created_at', DateTime(timezone=False),
+               default=utils.utcnow()),
+        Column('updated_at', DateTime(timezone=False),
+               onupdate=utils.utcnow()),
+        Column('deleted_at', DateTime(timezone=False)),
+        Column('deleted', Boolean(create_constraint=True, name=None)),
+        Column('id', Integer(), primary_key=True),
+        Column('network_info', Text()),
+        Column('instance_id', String(36),
+               ForeignKey('instances.uuid'),
+               nullable=False,
+               unique=True),
+        mysql_engine='InnoDB')
+
+
+def upgrade(migrate_engine):
+    meta.bind = migrate_engine
+
+    # load instances for fk
+    instances = Table('instances', meta, autoload=True)
+
+    # create instance_info_caches table
+    try:
+        instance_info_caches.create()
+    except Exception:
+        logging.error(_("Table |%s| not created!"), repr(instance_info_caches))
+        raise
+
+
+def downgrade(migrate_engine):
+    try:
+        instance_info_caches.drop()
+    except Exception:
+        logging.error(_("instance_info_caches tables not dropped"))
+        raise
diff --git a/nova/db/sqlalchemy/models.py b/nova/db/sqlalchemy/models.py
index 407c9e2e7..1774e9ea8 100644
--- a/nova/db/sqlalchemy/models.py
+++ b/nova/db/sqlalchemy/models.py
@@ -257,6 +257,27 @@ class Instance(BASE, NovaBase):
     progress = Column(Integer)
 
 
+class InstanceInfoCache(BASE, NovaBase):
+    """
+    Represents a cache of information about an instance
+    """
+    __tablename__ = 'instance_info_caches'
+    id = Column(String(36), primary_key=True)
+
+    # text column used for storing a json object of network data for api
+    network_info = Column(Text)
+
+    # this is all uuid based, we have them might as well start using them
+    instance_id = Column(String(36), ForeignKey('instances.uuid'),
+                                     nullable=False, unique=True)
+    instance = relationship(Instance,
+                            backref=backref('info_cache', uselist=False),
+                            foreign_keys=instance_id,
+                            primaryjoin='and_('
+                              'InstanceInfoCache.instance_id == Instance.uuid,'
+                              'InstanceInfoCache.deleted == False)')
+
+
 class VirtualStorageArray(BASE, NovaBase):
     """
     Represents a virtual storage array supplying block storage to instances.