The ironic_inspector.node_cache Module

Cache for nodes currently under introspection.

class ironic_inspector.node_cache.NodeInfo(uuid, version_id=None, state=None, started_at=None, finished_at=None, error=None, node=None, ports=None, ironic=None, lock=None)

Bases: 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.

acquire_lock(blocking=True)

Acquire a lock on the associated node.

Exits with success if a lock is already acquired using this NodeInfo object.

Parameters:blocking – if True, wait for lock to be acquired, otherwise return immediately. Returns:boolean value, whether lock was acquired successfully

add_attribute(name, value, session=None)

Store look up attribute for a node in the database.

Parameters:

• name – attribute name
• value – attribute value or list of possible values
• session – optional existing database session

attributes

Node look up attributes as a dict.

commit()

Commit current node status into the database.

create_ports(ports, ironic=None)

Create one or several ports for this node.

Parameters:ports –

List of ports with all their attributes e.g [{‘mac’: xx, ‘ip’: xx, ‘client_id’: None},

{‘mac’: xx, ‘ip’: None, ‘client_id’: None}]

It also support the old style of list of macs.

A warning is issued if port already exists on a node. :param ironic: Ironic client to use instead of self.ironic

delete_port(port, ironic=None)

Delete port.

Parameters:

• port – port object or its MAC
• ironic – Ironic client to use instead of self.ironic

finished(error=None)

Record status for this node.

Also deletes look up attributes from the cache.

Parameters:error – error message

classmethod from_row(row, ironic=None, lock=None, node=None)

Construct NodeInfo from a database row.

fsm_event(event, strict=False)

Update node_info.state based on a fsm.process_event(event) call.

An AutomatonException triggers an error event. If strict, node_info.finished(error=str(exc)) is called with the AutomatonException instance and a EventError raised.

Parameters:event – an event to process by the fsm Strict:whether to fail the introspection upon an invalid event Raises:NodeStateInvalidEvent

get_by_path(path)

Get field value by ironic-style path (e.g. /extra/foo).

Parameters:path – path to a field Returns:field value Raises:KeyError if field was not found

invalidate_cache()

Clear all cached info, so that it’s reloaded next time.

ironic

Ironic client instance.

node(ironic=None)

Get Ironic node object associated with the cached node record.

options

Node introspection options as a dict.

patch(patches, ironic=None)

Apply JSON patches to a node.

Refreshes cached node instance.

Parameters:

• patches – JSON patches to apply
• ironic – Ironic client to use instead of self.ironic

Raises:

ironicclient exceptions

patch_port(port, patches, ironic=None)

Apply JSON patches to a port.

Parameters:

• port – port object or its MAC
• patches – JSON patches to apply
• ironic – Ironic client to use instead of self.ironic

ports(ironic=None)

Get Ironic port objects associated with the cached node record.

This value is cached as well, use invalidate_cache() to clean.

Returns:dict MAC -> port object

release_lock()

Release a lock on a node.

Does nothing if lock was not acquired using this NodeInfo object.

replace_field(path, func, **kwargs)

Replace a field on ironic node.

Parameters:

• path – path to a field as used by the ironic client
• func – function accepting an old value and returning a new one
• 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

set_option(name, value)

Set an option for a node.

state

State of the node_info object.

update_capabilities(ironic=None, **caps)

Update capabilities on a node.

Parameters:

• caps – capabilities to update
• ironic – Ironic client to use instead of self.ironic

update_properties(ironic=None, **props)

Update properties on a node.

Parameters:

• props – properties to update
• ironic – Ironic client to use instead of self.ironic

version_id

Get the version id

ironic_inspector.node_cache.active_macs()

List all MAC’s that are on introspection right now.

ironic_inspector.node_cache.add_node(uuid, state, **attributes)

Store information about a node under introspection.

All existing information about this node is dropped. Empty values are skipped.

Parameters:

• uuid – Ironic node UUID
• state – The initial state of the node
• attributes – attributes known about this node (like macs, BMC etc); also ironic client instance may be passed under ‘ironic’

Returns:

NodeInfo

ironic_inspector.node_cache.clean_up()

Clean up the cache.

• Finish introspection for timed out nodes.
• Drop outdated node status information.

Returns:list of timed out node UUID’s

ironic_inspector.node_cache.create_node(driver, ironic=None, **attributes)

Create ironic node and cache it.

• Create new node in ironic.
• Cache it in inspector.
• Sets node_info state to enrolling.

Parameters:

• driver – driver for Ironic node.
• ironic – ronic client instance.
• attributes – dict, additional keyword arguments to pass to the ironic client on node creation.

Returns:

NodeInfo, or None in case error happened.

ironic_inspector.node_cache.delete_nodes_not_in_list(uuids)

Delete nodes which don’t exist in Ironic node UUIDs.

Parameters:uuids – Ironic node UUIDs

ironic_inspector.node_cache.find_node(**attributes)

Find node in cache.

Looks up a node based on attributes in a best-match fashion. This function acquires a lock on a node.

Parameters: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 or multiple nodes match the attributes

ironic_inspector.node_cache.fsm_event_after(event, strict=False)

Trigger an fsm event after the function execution.

It is assumed the first function arg of the decorated function is always a NodeInfo instance.

Parameters:

• event – the event to process after the function call
• strict – make an invalid fsm event trigger an error event

ironic_inspector.node_cache.fsm_event_before(event, strict=False)

Trigger an fsm event before the function execution.

It is assumed the first function arg of the decorated function is always a NodeInfo instance.

Parameters:

• event – the event to process before the function call
• strict – make an invalid fsm event trigger an error event

ironic_inspector.node_cache.fsm_transition(event, reentrant=True, **exc_kwargs)

Decorate a function to perform a (non-)reentrant transition.

If True, reentrant transition will be performed at the end of a function call. If False, the transition will be performed before the function call. The function is decorated with the triggers_fsm_error_transition decorator as well.

Parameters:

• event – the event to bind the transition to.
• reentrant – whether the transition is reentrant.
• exc_kwargs – passed on to the triggers_fsm_error_transition decorator

ironic_inspector.node_cache.get_node(node_id, ironic=None, locked=False)

Get node from cache.

Parameters:

• node_id – node UUID or name.
• ironic – optional ironic client instance
• locked – if True, get a lock on node before fetching its data

Returns:

structure NodeInfo.

ironic_inspector.node_cache.get_node_list(ironic=None, marker=None, limit=None)

Get node list from the cache.

The list of the nodes is ordered based on the (started_at, uuid) attribute pair, newer items first.

Parameters:

• ironic – optional ironic client instance
• marker – pagination marker (an UUID or None)
• limit – pagination limit; None for default CONF.api_max_limit

Returns:

a list of NodeInfo instances.

ironic_inspector.node_cache.introspection_active()

Check if introspection is active for at least one node.

ironic_inspector.node_cache.release_lock(func)

Decorate a node_info-function to release the node_info lock.

Assumes the first parameter of the function func is always a NodeInfo instance.

ironic_inspector.node_cache.start_introspection(uuid, **kwargs)

Start the introspection of a node.

If a node_info record exists in the DB, a start transition is used rather than dropping the record in order to check for the start transition validity in particular node state.

Parameters:

• uuid – Ironic node UUID
• kwargs – passed on to add_node()

Raises:

NodeStateInvalidEvent in case the start transition is invalid in the current node state

Raises:

NodeStateRaceCondition if a mismatch was detected between the node_info cache and the DB

Returns:

NodeInfo

ironic_inspector.node_cache.triggers_fsm_error_transition(errors=(<type 'exceptions.Exception'>, ), no_errors=(<class 'ironic_inspector.utils.NodeStateInvalidEvent'>, <class 'ironic_inspector.utils.NodeStateRaceCondition'>))

Trigger an fsm error transition upon certain errors.

It is assumed the first function arg of the decorated function is always a NodeInfo instance.

Parameters:

• errors – a tuple of exceptions upon which an error event is triggered. Re-raised.
• no_errors – a tuple of exceptions that won’t trigger the error event.