openstack/nova
Code Issues Proposed changes

Add instance_system_metadata modeling.

Browse Source 
Implements blueprint instance-system-metadata.

Adds a new table to store system-owned metadata tied to an instance. The
intent is to provide a key/value store that compute plugins can use to
persist state.

Change-Id: Ic446fea0f9c8a652f2ac6d554f4f85021ce34fb8
This commit is contained in:
Rick Harris 2012-05-02 21:40:14 +00:00
parent 7d8231a58c
commit 066d4c0bf2
6 changed files with 248 additions and 21 deletions
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19
nova/db/api.py
View File

@ -1488,6 +1488,25 @@ def instance_metadata_update(context, instance_id, metadata, delete):
####################
def instance_system_metadata_get(context, instance_uuid):
"""Get all system metadata for an instance."""
return IMPL.instance_system_metadata_get(context, instance_uuid)
def instance_system_metadata_delete(context, instance_uuid, key):
"""Delete the given system metadata item."""
IMPL.instance_system_metadata_delete(context, instance_uuid, key)
def instance_system_metadata_update(context, instance_uuid, metadata, delete):
"""Update metadata if it exists, otherwise create it."""
IMPL.instance_system_metadata_update(
context, instance_uuid, metadata, delete)
####################
def agent_build_create(context, values):
"""Create a new agent build entry."""
return IMPL.agent_build_create(context, values)

125
nova/db/sqlalchemy/api.py
View File

@ -136,11 +136,25 @@ def require_instance_exists(f):
Requires the wrapped function to use context and instance_id as
their first two arguments.
"""
@functools.wraps(f)
def wrapper(context, instance_id, *args, **kwargs):
db.instance_get(context, instance_id)
return f(context, instance_id, *args, **kwargs)
wrapper.__name__ = f.__name__
return wrapper
def require_instance_exists_using_uuid(f):
"""Decorator to require the specified instance to exist.
Requires the wrapped function to use context and instance_uuid as
their first two arguments.
"""
@functools.wraps(f)
def wrapper(context, instance_uuid, *args, **kwargs):
db.instance_get_by_uuid(context, instance_uuid)
return f(context, instance_uuid, *args, **kwargs)
return wrapper
@ -1259,8 +1273,12 @@ def instance_create(context, values):
values - dict containing column values.
"""
values = values.copy()
values['metadata'] = _metadata_refs(values.get('metadata'),
models.InstanceMetadata)
values['metadata'] = _metadata_refs(
values.get('metadata'), models.InstanceMetadata)
values['system_metadata'] = _metadata_refs(
values.get('system_metadata'), models.InstanceSystemMetadata)
instance_ref = models.Instance()
if not values.get('uuid'):
values['uuid'] = str(utils.gen_uuid())
@ -1620,10 +1638,15 @@ def instance_update(context, instance_id, values):
metadata = values.get('metadata')
if metadata is not None:
instance_metadata_update(context,
instance_ref['id'],
values.pop('metadata'),
delete=True)
instance_metadata_update(
context, instance_ref['id'], values.pop('metadata'), delete=True)
system_metadata = values.get('system_metadata')
if system_metadata is not None:
instance_system_metadata_update(
context, instance_ref['uuid'], values.pop('system_metadata'),
delete=True)
with session.begin():
instance_ref.update(values)
instance_ref.save(session=session)
@ -3682,8 +3705,8 @@ def cell_get_all(context):
return model_query(context, models.Cell, read_deleted="no").all()
####################
########################
# User-provided metadata
def _instance_metadata_get_query(context, instance_id, session=None):
return model_query(context, models.InstanceMetadata, session=session,
@ -3764,6 +3787,88 @@ def instance_metadata_update(context, instance_id, metadata, delete):
return metadata
#######################
# System-owned metadata
def _instance_system_metadata_get_query(context, instance_uuid, session=None):
return model_query(context, models.InstanceSystemMetadata, session=session,
read_deleted="no").\
filter_by(instance_uuid=instance_uuid)
@require_context
@require_instance_exists_using_uuid
def instance_system_metadata_get(context, instance_uuid):
rows = _instance_system_metadata_get_query(context, instance_uuid).all()
result = {}
for row in rows:
result[row['key']] = row['value']
return result
@require_context
@require_instance_exists_using_uuid
def instance_system_metadata_delete(context, instance_uuid, key):
_instance_system_metadata_get_query(context, instance_uuid).\
filter_by(key=key).\
update({'deleted': True,
'deleted_at': utils.utcnow(),
'updated_at': literal_column('updated_at')})
def _instance_system_metadata_get_item(context, instance_uuid, key,
session=None):
result = _instance_system_metadata_get_query(
context, instance_uuid, session=session).\
filter_by(key=key).\
first()
if not result:
raise exception.InstanceSystemMetadataNotFound(
metadata_key=key, instance_uuid=instance_uuid)
return result
@require_context
@require_instance_exists_using_uuid
def instance_system_metadata_update(context, instance_uuid, metadata, delete):
session = get_session()
# Set existing metadata to deleted if delete argument is True
if delete:
original_metadata = instance_system_metadata_get(
context, instance_uuid)
for meta_key, meta_value in original_metadata.iteritems():
if meta_key not in metadata:
meta_ref = _instance_system_metadata_get_item(
context, instance_uuid, meta_key, session)
meta_ref.update({'deleted': True})
meta_ref.save(session=session)
meta_ref = None
# Now update all existing items with new values, or create new meta objects
for meta_key, meta_value in metadata.iteritems():
# update the value whether it exists or not
item = {"value": meta_value}
try:
meta_ref = _instance_system_metadata_get_item(
context, instance_uuid, meta_key, session)
except exception.InstanceSystemMetadataNotFound, e:
meta_ref = models.InstanceSystemMetadata()
item.update({"key": meta_key, "instance_uuid": instance_uuid})
meta_ref.update(item)
meta_ref.save(session=session)
return metadata
####################

71
nova/db/sqlalchemy/migrate_repo/versions/092_add_instance_system_metadata.py Normal file
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@ -0,0 +1,71 @@
# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2012 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.
from sqlalchemy import Boolean, Column, DateTime, ForeignKey, Integer
from sqlalchemy import MetaData, String, Table
from nova import log as logging
LOG = logging.getLogger(__name__)
def upgrade(migrate_engine):
# Upgrade operations go here. Don't create your own engine;
# bind migrate_engine to your metadata
meta = MetaData()
meta.bind = migrate_engine
# load tables for fk
instances = Table('instances', meta, autoload=True)
instance_system_metadata = Table('instance_system_metadata', meta,
Column('created_at', DateTime(timezone=False)),
Column('updated_at', DateTime(timezone=False)),
Column('deleted_at', DateTime(timezone=False)),
Column('deleted', Boolean(create_constraint=True, name=None)),
Column('id', Integer(), primary_key=True, nullable=False),
Column('instance_uuid',
String(36),
ForeignKey('instances.uuid'),
nullable=False),
Column('key',
String(length=255, convert_unicode=True,
assert_unicode=None,
unicode_error=None, _warn_on_bytestring=False),
nullable=False),
Column('value',
String(length=255, convert_unicode=True,
assert_unicode=None,
unicode_error=None, _warn_on_bytestring=False)),
mysql_engine='InnoDB')
try:
instance_system_metadata.create()
except Exception:
LOG.error(_("Table |%s| not created!"), repr(instance_system_metadata))
raise
def downgrade(migrate_engine):
meta = MetaData()
meta.bind = migrate_engine
# load tables for fk
instances = Table('instances', meta, autoload=True)
instance_system_metadata = Table(
'instance_system_metadata', meta, autoload=True)
instance_system_metadata.drop()

19
nova/db/sqlalchemy/models.py
View File

@ -831,7 +831,7 @@ class Console(BASE, NovaBase):
class InstanceMetadata(BASE, NovaBase):
"""Represents a metadata key/value pair for an instance"""
"""Represents a user-provided metadata key/value pair for an instance"""
__tablename__ = 'instance_metadata'
id = Column(Integer, primary_key=True)
key = Column(String(255))
@ -844,6 +844,23 @@ class InstanceMetadata(BASE, NovaBase):
'InstanceMetadata.deleted == False)')
class InstanceSystemMetadata(BASE, NovaBase):
"""Represents a system-owned metadata key/value pair for an instance"""
__tablename__ = 'instance_system_metadata'
id = Column(Integer, primary_key=True)
key = Column(String(255))
value = Column(String(255))
instance_uuid = Column(String(36),
ForeignKey('instances.uuid'),
nullable=False)
primary_join = ('and_(InstanceSystemMetadata.instance_uuid == '
'Instance.uuid, InstanceSystemMetadata.deleted == False)')
instance = relationship(Instance, backref="system_metadata",
foreign_keys=instance_uuid,
primaryjoin=primary_join)
class InstanceTypeExtraSpecs(BASE, NovaBase):
"""Represents additional specs as key/value pairs for an instance_type"""
__tablename__ = 'instance_type_extra_specs'

5
nova/exception.py
View File

@ -811,6 +811,11 @@ class InstanceMetadataNotFound(NotFound):
"key %(metadata_key)s.")
class InstanceSystemMetadataNotFound(NotFound):
message = _("Instance %(instance_uuid)s has no system metadata with "
"key %(metadata_key)s.")
class InstanceTypeExtraSpecsNotFound(NotFound):
message = _("Instance Type %(instance_type_id)s has no extra specs with "
"key %(extra_specs_key)s.")

30
nova/tests/test_db_api.py
View File

@ -168,37 +168,47 @@ class DbApiTestCase(test.TestCase):
ctxt = context.get_admin_context()
# Create an instance with some metadata
metadata = {'host': 'foo'}
values = {'metadata': metadata}
values = {'metadata': {'host': 'foo'},
'system_metadata': {'original_image_ref': 'blah'}}
instance = db.instance_create(ctxt, values)
# Update the metadata
metadata = {'host': 'bar'}
values = {'metadata': metadata}
values = {'metadata': {'host': 'bar'},
'system_metadata': {'original_image_ref': 'baz'}}
db.instance_update(ctxt, instance.id, values)
# Retrieve the metadata to ensure it was successfully updated
# Retrieve the user-provided metadata to ensure it was successfully
# updated
instance_meta = db.instance_metadata_get(ctxt, instance.id)
self.assertEqual('bar', instance_meta['host'])
# Retrieve the system metadata to ensure it was successfully updated
system_meta = db.instance_system_metadata_get(ctxt, instance.uuid)
self.assertEqual('baz', system_meta['original_image_ref'])
def test_instance_update_with_instance_uuid(self):
""" test instance_update() works when an instance UUID is passed """
ctxt = context.get_admin_context()
# Create an instance with some metadata
metadata = {'host': 'foo'}
values = {'metadata': metadata}
values = {'metadata': {'host': 'foo'},
'system_metadata': {'original_image_ref': 'blah'}}
instance = db.instance_create(ctxt, values)
# Update the metadata
metadata = {'host': 'bar'}
values = {'metadata': metadata}
values = {'metadata': {'host': 'bar'},
'system_metadata': {'original_image_ref': 'baz'}}
db.instance_update(ctxt, instance.uuid, values)
# Retrieve the metadata to ensure it was successfully updated
# Retrieve the user-provided metadata to ensure it was successfully
# updated
instance_meta = db.instance_metadata_get(ctxt, instance.id)
self.assertEqual('bar', instance_meta['host'])
# Retrieve the system metadata to ensure it was successfully updated
system_meta = db.instance_system_metadata_get(ctxt, instance.uuid)
self.assertEqual('baz', system_meta['original_image_ref'])
def test_instance_fault_create(self):
"""Ensure we can create an instance fault"""
ctxt = context.get_admin_context()