ironic-inspector/ironic_discoverd/node_cache.py

126 lines
3.8 KiB
Python

# 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.
"""Cache for nodes currently under discovery."""
import logging
import sqlite3
import time
from ironic_discoverd import conf
from ironic_discoverd import utils
LOG = logging.getLogger("discoverd")
_DB = None
_SCHEMA = """
create table if not exists nodes
(uuid text primary key, started_at real);
create table if not exists attributes
(name text, value text, uuid text,
primary key (name, value),
foreign key (uuid) references nodes);
"""
def init():
"""Initialize the database."""
global _DB
conn = conf.get('discoverd', 'database') or ':memory:'
_DB = sqlite3.connect(conn)
_DB.executescript(_SCHEMA)
def _db():
if _DB is None:
init()
return _DB
def add_node(uuid, **attributes):
"""Store information about a node under discovery.
All existing information about this node is dropped.
Empty values are skipped.
:param uuid: Ironic node UUID
:param attributes: attributes known about this node (like macs, BMC etc)
"""
drop_node(uuid)
with _db():
_db().execute("insert into nodes(uuid, started_at) "
"values(?, ?)", (uuid, time.time()))
for (name, value) in attributes.items():
if not value:
continue
if not isinstance(value, list):
value = [value]
try:
_db().executemany("insert into attributes(name, value, uuid) "
"values(?, ?, ?)",
[(name, v, uuid) for v in value])
except sqlite3.IntegrityError:
raise utils.DiscoveryFailed(
'Some or all of %(name)s\'s %(value)s are already '
'on discovery' %
{'name': name, 'value': value})
def drop_node(uuid):
"""Forget information about node with given uuid."""
with _db():
_db().execute("delete from nodes where uuid=?", (uuid,))
_db().execute("delete from attributes where uuid=?", (uuid,))
def pop_node(**attributes):
"""Find node in cache.
This function also deletes a node from the cache, thus it's name.
:param attributes: attributes known about this node (like macs, BMC etc)
:returns: UUID or None
"""
# NOTE(dtantsur): sorting is not required, but gives us predictability
found = set()
for (name, value) in sorted(attributes.items()):
if not value:
LOG.warning('Empty value for attribute %s', name)
continue
if not isinstance(value, list):
value = [value]
LOG.debug('Trying to use %s %s for discovery' % (name, value))
rows = _db().execute('select distinct uuid from attributes where ' +
' OR '.join('name=? AND value=?' for _ in value),
sum(([name, v] for v in value), [])).fetchall()
if rows:
found.update(item[0] for item in rows)
if not found:
LOG.error('Could not find a node based on attributes %s',
list(attributes))
return
elif len(found) > 1:
LOG.error('Multiple nodes were matched based on attributes %(keys)s: '
'%(uuids)s',
{'keys': list(attributes),
'uuids': list(found)})
return
uuid = found.pop()
drop_node(uuid)
return uuid