Source code for ironic_inspector.node_cache

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#    http://www.apache.org/licenses/LICENSE-2.0
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"""Cache for nodes currently under introspection."""

import copy
import json
import time

from ironicclient import exceptions
from oslo_concurrency import lockutils
from oslo_config import cfg
from oslo_db import exception as db_exc
from oslo_utils import excutils
from sqlalchemy import text

from ironic_inspector import db
from ironic_inspector.common.i18n import _, _LE, _LW, _LI
from ironic_inspector.common import ironic as ir_utils
from ironic_inspector import utils

CONF = cfg.CONF


LOG = utils.getProcessingLogger(__name__)


MACS_ATTRIBUTE = 'mac'
_LOCK_TEMPLATE = 'node-%s'
_SEMAPHORES = lockutils.Semaphores()


def _get_lock(uuid):
    """Get lock object for a given node UUID."""
    return lockutils.internal_lock(_LOCK_TEMPLATE % uuid,
                                   semaphores=_SEMAPHORES)


def _get_lock_ctx(uuid):
    """Get context manager yielding a lock object for a given node UUID."""
    return lockutils.lock(_LOCK_TEMPLATE % uuid, semaphores=_SEMAPHORES)


[docs]class NodeInfo(object): """Record about a node in the cache. This class optionally allows to acquire a lock on a node. Note that the class instance itself is NOT thread-safe, you need to create a new instance for every thread. """ def __init__(self, uuid, started_at=None, finished_at=None, error=None, node=None, ports=None, ironic=None, lock=None): self.uuid = uuid self.started_at = started_at self.finished_at = finished_at self.error = error self.invalidate_cache() self._node = node if ports is not None and not isinstance(ports, dict): ports = {p.address: p for p in ports} self._ports = ports self._attributes = None self._ironic = ironic # This is a lock on a node UUID, not on a NodeInfo object self._lock = lock if lock is not None else _get_lock(uuid) # Whether lock was acquired using this NodeInfo object self._locked = lock is not None def __del__(self): if self._locked: LOG.warning(_LW('BUG: node lock was not released by the moment ' 'node info object is deleted')) self._lock.release()
[docs] def acquire_lock(self, blocking=True): """Acquire a lock on the associated node. Exits with success if a lock is already acquired using this NodeInfo object. :param blocking: if True, wait for lock to be acquired, otherwise return immediately. :returns: boolean value, whether lock was acquired successfully """ if self._locked: return True LOG.debug('Attempting to acquire lock', node_info=self) if self._lock.acquire(blocking): self._locked = True LOG.debug('Successfully acquired lock', node_info=self) return True else: LOG.debug('Unable to acquire lock', node_info=self) return False
[docs] def release_lock(self): """Release a lock on a node. Does nothing if lock was not acquired using this NodeInfo object. """ if self._locked: LOG.debug('Successfully released lock', node_info=self) self._lock.release() self._locked = False
@property
[docs] def options(self): """Node introspection options as a dict.""" if self._options is None: rows = db.model_query(db.Option).filter_by( uuid=self.uuid) self._options = {row.name: json.loads(row.value) for row in rows} return self._options
@property
[docs] def attributes(self): """Node look up attributes as a dict.""" if self._attributes is None: self._attributes = {} rows = db.model_query(db.Attribute).filter_by( uuid=self.uuid) for row in rows: self._attributes.setdefault(row.name, []).append(row.value) return self._attributes
@property
[docs] def ironic(self): """Ironic client instance.""" if self._ironic is None: self._ironic = ir_utils.get_client() return self._ironic
[docs] def set_option(self, name, value): """Set an option for a node.""" encoded = json.dumps(value) self.options[name] = value with db.ensure_transaction() as session: db.model_query(db.Option, session=session).filter_by( uuid=self.uuid, name=name).delete() db.Option(uuid=self.uuid, name=name, value=encoded).save( session)
[docs] def finished(self, error=None): """Record status for this node. Also deletes look up attributes from the cache. :param error: error message """ self.release_lock() self.finished_at = time.time() self.error = error with db.ensure_transaction() as session: db.model_query(db.Node, session=session).filter_by( uuid=self.uuid).update( {'finished_at': self.finished_at, 'error': error}) db.model_query(db.Attribute, session=session).filter_by( uuid=self.uuid).delete() db.model_query(db.Option, session=session).filter_by( uuid=self.uuid).delete()
[docs] def add_attribute(self, name, value, session=None): """Store look up attribute for a node in the database. :param name: attribute name :param value: attribute value or list of possible values :param session: optional existing database session :raises: Error if attributes values are already in database """ if not isinstance(value, list): value = [value] with db.ensure_transaction(session) as session: try: for v in value: db.Attribute(name=name, value=v, uuid=self.uuid).save( session) except db_exc.DBDuplicateEntry as exc: LOG.error(_LE('Database integrity error %s during ' 'adding attributes'), exc, node_info=self) raise utils.Error(_( 'Some or all of %(name)s\'s %(value)s are already ' 'on introspection') % {'name': name, 'value': value}, node_info=self) # Invalidate attributes so they're loaded on next usage self._attributes = None
@classmethod
[docs] def from_row(cls, row, ironic=None, lock=None): """Construct NodeInfo from a database row.""" fields = {key: row[key] for key in ('uuid', 'started_at', 'finished_at', 'error')} return cls(ironic=ironic, lock=lock, **fields)
[docs] def invalidate_cache(self): """Clear all cached info, so that it's reloaded next time.""" self._options = None self._node = None self._ports = None self._attributes = None self._ironic = None
[docs] def node(self): """Get Ironic node object associated with the cached node record.""" if self._node is None: self._node = self.ironic.node.get(self.uuid) return self._node
[docs] def create_ports(self, macs): """Create one or several ports for this node. A warning is issued if port already exists on a node. """ for mac in macs: if mac not in self.ports(): self._create_port(mac) else: LOG.warning(_LW('Port %s already exists, skipping'), mac, node_info=self)
[docs] def ports(self): """Get Ironic port objects associated with the cached node record. This value is cached as well, use invalidate_cache() to clean. :return: dict MAC -> port object """ if self._ports is None: self._ports = {p.address: p for p in self.ironic.node.list_ports(self.uuid, limit=0)} return self._ports
def _create_port(self, mac): try: port = self.ironic.port.create(node_uuid=self.uuid, address=mac) except exceptions.Conflict: LOG.warning(_LW('Port %s already exists, skipping'), mac, node_info=self) # NOTE(dtantsur): we didn't get port object back, so we have to # reload ports on next access self._ports = None else: self._ports[mac] = port
[docs] def patch(self, patches): """Apply JSON patches to a node. Refreshes cached node instance. :param patches: JSON patches to apply :raises: ironicclient exceptions """ # NOTE(aarefiev): support path w/o ahead forward slash # as Ironic cli does for patch in patches: if patch.get('path') and not patch['path'].startswith('/'): patch['path'] = '/' + patch['path'] LOG.debug('Updating node with patches %s', patches, node_info=self) self._node = self.ironic.node.update(self.uuid, patches)
[docs] def patch_port(self, port, patches): """Apply JSON patches to a port. :param port: port object or its MAC :param patches: JSON patches to apply """ ports = self.ports() if isinstance(port, str): port = ports[port] LOG.debug('Updating port %(mac)s with patches %(patches)s', {'mac': port.address, 'patches': patches}, node_info=self) new_port = self.ironic.port.update(port.uuid, patches) ports[port.address] = new_port
[docs] def update_properties(self, **props): """Update properties on a node. :param props: properties to update """ patches = [{'op': 'add', 'path': '/properties/%s' % k, 'value': v} for k, v in props.items()] self.patch(patches)
[docs] def update_capabilities(self, **caps): """Update capabilities on a node. :param props: capabilities to update """ existing = ir_utils.capabilities_to_dict( self.node().properties.get('capabilities')) existing.update(caps) self.update_properties( capabilities=ir_utils.dict_to_capabilities(existing))
[docs] def delete_port(self, port): """Delete port. :param port: port object or its MAC """ ports = self.ports() if isinstance(port, str): port = ports[port] self.ironic.port.delete(port.uuid) del ports[port.address]
[docs] def get_by_path(self, path): """Get field value by ironic-style path (e.g. /extra/foo). :param path: path to a field :returns: field value :raises: KeyError if field was not found """ path = path.strip('/') try: if '/' in path: prop, key = path.split('/', 1) return getattr(self.node(), prop)[key] else: return getattr(self.node(), path) except AttributeError: raise KeyError(path)
[docs] def replace_field(self, path, func, **kwargs): """Replace a field on ironic node. :param path: path to a field as used by the ironic client :param func: function accepting an old value and returning a new one :param kwargs: if 'default' value is passed here, it will be used when no existing value is found. :raises: KeyError if value is not found and default is not set :raises: everything that patch() may raise """ try: value = self.get_by_path(path) op = 'replace' except KeyError: if 'default' in kwargs: value = kwargs['default'] op = 'add' else: raise ref_value = copy.deepcopy(value) value = func(value) if value != ref_value: self.patch([{'op': op, 'path': path, 'value': value}])
[docs]def add_node(uuid, **attributes): """Store information about a node under introspection. 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); also ironic client instance may be passed under 'ironic' :returns: NodeInfo """ started_at = time.time() with db.ensure_transaction() as session: _delete_node(uuid) db.Node(uuid=uuid, started_at=started_at).save(session) node_info = NodeInfo(uuid=uuid, started_at=started_at, ironic=attributes.pop('ironic', None)) for (name, value) in attributes.items(): if not value: continue node_info.add_attribute(name, value, session=session) return node_info
[docs]def delete_nodes_not_in_list(uuids): """Delete nodes which don't exist in Ironic node UUIDs. :param uuids: Ironic node UUIDs """ inspector_uuids = _list_node_uuids() for uuid in inspector_uuids - uuids: LOG.warning( _LW('Node %s was deleted from Ironic, dropping from Ironic ' 'Inspector database'), uuid) with _get_lock_ctx(uuid): _delete_node(uuid)
def _delete_node(uuid, session=None): """Delete information about a node. :param uuid: Ironic node UUID :param session: optional existing database session """ with db.ensure_transaction(session) as session: for model in (db.Attribute, db.Option, db.Node): db.model_query(model, session=session).filter_by(uuid=uuid).delete()
[docs]def introspection_active(): """Check if introspection is active for at least one node.""" # FIXME(dtantsur): is there a better way to express it? return (db.model_query(db.Node.uuid).filter_by(finished_at=None).first() is not None)
[docs]def active_macs(): """List all MAC's that are on introspection right now.""" return ({x.value for x in db.model_query(db.Attribute.value). filter_by(name=MACS_ATTRIBUTE)})
def _list_node_uuids(): """Get all nodes' uuid from cache. :returns: Set of nodes' uuid. """ return {x.uuid for x in db.model_query(db.Node.uuid)}
[docs]def get_node(uuid, ironic=None, locked=False): """Get node from cache by it's UUID. :param uuid: node UUID. :param ironic: optional ironic client instance :param locked: if True, get a lock on node before fetching its data :returns: structure NodeInfo. """ if locked: lock = _get_lock(uuid) lock.acquire() else: lock = None try: row = db.model_query(db.Node).filter_by(uuid=uuid).first() if row is None: raise utils.Error(_('Could not find node %s in cache') % uuid, code=404) return NodeInfo.from_row(row, ironic=ironic, lock=lock) except Exception: with excutils.save_and_reraise_exception(): if lock is not None: lock.release()
[docs]def find_node(**attributes): """Find node in cache. This function acquires a lock on a node. :param attributes: attributes known about this node (like macs, BMC etc) also ironic client instance may be passed under 'ironic' :returns: structure NodeInfo with attributes ``uuid`` and ``created_at`` :raises: Error if node is not found """ ironic = attributes.pop('ironic', None) # NOTE(dtantsur): sorting is not required, but gives us predictability found = set() for (name, value) in sorted(attributes.items()): if not value: LOG.debug('Empty value for attribute %s', name) continue if not isinstance(value, list): value = [value] LOG.debug('Trying to use %s of value %s for node look up' % (name, value)) value_list = [] for v in value: value_list.append("name='%s' AND value='%s'" % (name, v)) stmt = ('select distinct uuid from attributes where ' + ' OR '.join(value_list)) rows = (db.model_query(db.Attribute.uuid).from_statement( text(stmt)).all()) if rows: found.update(item.uuid for item in rows) if not found: raise utils.NotFoundInCacheError(_( 'Could not find a node for attributes %s') % attributes) elif len(found) > 1: raise utils.Error(_( 'Multiple matching nodes found for attributes ' '%(attr)s: %(found)s') % {'attr': attributes, 'found': list(found)}, code=404) uuid = found.pop() node_info = NodeInfo(uuid=uuid, ironic=ironic) node_info.acquire_lock() try: row = (db.model_query(db.Node.started_at, db.Node.finished_at). filter_by(uuid=uuid).first()) if not row: raise utils.Error(_( 'Could not find node %s in introspection cache, ' 'probably it\'s not on introspection now') % uuid, code=404) if row.finished_at: raise utils.Error(_( 'Introspection for node %(node)s already finished on ' '%(finish)s') % {'node': uuid, 'finish': row.finished_at}) node_info.started_at = row.started_at return node_info except Exception: with excutils.save_and_reraise_exception(): node_info.release_lock()
[docs]def clean_up(): """Clean up the cache. * Finish introspection for timed out nodes. * Drop outdated node status information. :return: list of timed out node UUID's """ status_keep_threshold = (time.time() - CONF.node_status_keep_time) with db.ensure_transaction() as session: db.model_query(db.Node, session=session).filter( db.Node.finished_at.isnot(None), db.Node.finished_at < status_keep_threshold).delete() timeout = CONF.timeout if timeout <= 0: return [] threshold = time.time() - timeout uuids = [row.uuid for row in db.model_query(db.Node.uuid, session=session).filter( db.Node.started_at < threshold, db.Node.finished_at.is_(None)).all()] if not uuids: return [] LOG.error(_LE('Introspection for nodes %s has timed out'), uuids) for u in uuids: node_info = get_node(u, locked=True) try: if node_info.finished_at or node_info.started_at > threshold: continue db.model_query(db.Node, session=session).filter_by( uuid=u).update({'finished_at': time.time(), 'error': 'Introspection timeout'}) db.model_query(db.Attribute, session=session).filter_by( uuid=u).delete() db.model_query(db.Option, session=session).filter_by( uuid=u).delete() finally: node_info.release_lock() return uuids
[docs]def create_node(driver, ironic=None, **attributes): """Create ironic node and cache it. * Create new node in ironic. * Cache it in inspector. :param driver: driver for Ironic node. :param ironic: ronic client instance. :param attributes: dict, additional keyword arguments to pass to the ironic client on node creation. :return: NodeInfo, or None in case error happened. """ if ironic is None: ironic = ir_utils.get_client() try: node = ironic.node.create(driver=driver, **attributes) except exceptions.InvalidAttribute as e: LOG.error(_LE('Failed to create new node: %s'), e) else: LOG.info(_LI('Node %s was created successfully'), node.uuid) return add_node(node.uuid, ironic=ironic)

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