def detect_changing_cause(
*,
finalizer: str,
raw_event: bodies.RawEvent,
body: bodies.Body,
old: Optional[bodies.BodyEssence] = None,
new: Optional[bodies.BodyEssence] = None,
diff: Optional[diffs.Diff] = None,
initial: bool = False,
**kwargs: Any,
) -> ChangingCause:
"""
Detect the cause of the event to be handled.
This is a purely computational function with no side-effects.
The causes are then consumed by `custom_object_handler`,
which performs the actual handler invocation, logging, patching,
and other side-effects.
"""
# Put them back to the pass-through kwargs (to avoid code duplication).
kwargs.update(body=body, old=old, new=new, initial=initial)
if diff is not None:
kwargs.update(diff=diff)
# The object was really deleted from the cluster. But we do not care anymore.
if raw_event['type'] == 'DELETED':
return ChangingCause(reason=Reason.GONE, **kwargs)
# The finalizer has been just removed. We are fully done.
deletion_is_ongoing = finalizers.is_deletion_ongoing(body=body)
deletion_is_blocked = finalizers.is_deletion_blocked(body=body,
finalizer=finalizer)
if deletion_is_ongoing and not deletion_is_blocked:
return ChangingCause(reason=Reason.FREE, **kwargs)
if deletion_is_ongoing:
return ChangingCause(reason=Reason.DELETE, **kwargs)
# For an object seen for the first time (i.e. just-created), call the creation handlers,
# then mark the state as if it was seen when the creation has finished.
# Creation never mixes with resuming, even if an object is detected on startup (first listing).
if old is None: # i.e. we have no essence stored
kwargs['initial'] = False
return ChangingCause(reason=Reason.CREATE, **kwargs)
# Cases with no essence changes are usually ignored (NOOP). But for the not-yet-resumed objects,
# we simulate a fake cause to invoke the resuming handlers. For cases with the essence changes,
# the resuming handlers will be mixed-in to the regular cause handling ("cuckoo-style")
# due to the ``initial=True`` flag on the cause, regardless of the reason.
if not diff and initial:
return ChangingCause(reason=Reason.RESUME, **kwargs)
# The previous step triggers one more patch operation without actual changes. Ignore it.
# Either the last-seen state or the status field has changed.
if not diff:
return ChangingCause(reason=Reason.NOOP, **kwargs)
# And what is left, is the update operation on one of the useful fields of the existing object.
return ChangingCause(reason=Reason.UPDATE, **kwargs)
async def process_resource_causes(
lifecycle: execution.LifeCycleFn,
indexers: indexing.OperatorIndexers,
registry: registries.OperatorRegistry,
settings: configuration.OperatorSettings,
resource: references.Resource,
raw_event: bodies.RawEvent,
body: bodies.Body,
patch: patches.Patch,
memory: inventory.ResourceMemory,
local_logger: loggers.ObjectLogger,
event_logger: loggers.ObjectLogger,
) -> Tuple[Collection[float], bool]:
finalizer = settings.persistence.finalizer
extra_fields = (
# NB: indexing handlers are useless here, they are handled on their own.
registry._watching.get_extra_fields(resource=resource) |
registry._changing.get_extra_fields(resource=resource) |
registry._spawning.get_extra_fields(resource=resource))
old = settings.persistence.diffbase_storage.fetch(body=body)
new = settings.persistence.diffbase_storage.build(body=body, extra_fields=extra_fields)
old = settings.persistence.progress_storage.clear(essence=old) if old is not None else None
new = settings.persistence.progress_storage.clear(essence=new) if new is not None else None
diff = diffs.diff(old, new)
# Detect what are we going to do on this processing cycle.
watching_cause = causes.detect_watching_cause(
raw_event=raw_event,
resource=resource,
indices=indexers.indices,
logger=local_logger,
patch=patch,
body=body,
memo=memory.memo,
) if registry._watching.has_handlers(resource=resource) else None
spawning_cause = causes.detect_spawning_cause(
resource=resource,
indices=indexers.indices,
logger=event_logger,
patch=patch,
body=body,
memo=memory.memo,
reset=bool(diff), # only essential changes reset idling, not every event
) if registry._spawning.has_handlers(resource=resource) else None
changing_cause = causes.detect_changing_cause(
finalizer=finalizer,
raw_event=raw_event,
resource=resource,
indices=indexers.indices,
logger=event_logger,
patch=patch,
body=body,
old=old,
new=new,
diff=diff,
memo=memory.memo,
initial=memory.noticed_by_listing and not memory.fully_handled_once,
) if registry._changing.has_handlers(resource=resource) else None
# If there are any handlers for this resource kind in general, but not for this specific object
# due to filters, then be blind to it, store no state, and log nothing about the handling cycle.
if changing_cause is not None and not registry._changing.prematch(cause=changing_cause):
changing_cause = None
# Block the object from deletion if we have anything to do in its end of life:
# specifically, if there are daemons to kill or mandatory on-deletion handlers to call.
# The high-level handlers are prevented if this event cycle is dedicated to the finalizer.
# The low-level handlers (on-event spying & daemon spawning) are still executed asap.
deletion_is_ongoing = finalizers.is_deletion_ongoing(body=body)
deletion_is_blocked = finalizers.is_deletion_blocked(body=body, finalizer=finalizer)
deletion_must_be_blocked = (
(spawning_cause is not None and
registry._spawning.requires_finalizer(
cause=spawning_cause,
excluded=memory.daemons_memory.forever_stopped,
))
or
(changing_cause is not None and
registry._changing.requires_finalizer(
cause=changing_cause,
)))
if deletion_must_be_blocked and not deletion_is_blocked and not deletion_is_ongoing:
local_logger.debug("Adding the finalizer, thus preventing the actual deletion.")
finalizers.block_deletion(body=body, patch=patch, finalizer=finalizer)
changing_cause = None # prevent further high-level processing this time
if not deletion_must_be_blocked and deletion_is_blocked:
local_logger.debug("Removing the finalizer, as there are no handlers requiring it.")
finalizers.allow_deletion(body=body, patch=patch, finalizer=finalizer)
changing_cause = None # prevent further high-level processing this time
# Invoke all the handlers that should or could be invoked at this processing cycle.
# The low-level spies go ASAP always. However, the daemons are spawned before the high-level
# handlers and killed after them: the daemons should live throughout the full object lifecycle.
if watching_cause is not None:
await process_watching_cause(
lifecycle=lifecycles.all_at_once,
registry=registry,
settings=settings,
cause=watching_cause,
)
spawning_delays: Collection[float] = []
if spawning_cause is not None:
spawning_delays = await process_spawning_cause(
registry=registry,
settings=settings,
memory=memory,
cause=spawning_cause,
)
changing_delays: Collection[float] = []
if changing_cause is not None:
changing_delays = await process_changing_cause(
lifecycle=lifecycle,
registry=registry,
settings=settings,
memory=memory,
cause=changing_cause,
)
# Release the object if everything is done, and it is marked for deletion.
# But not when it has already gone.
if deletion_is_ongoing and deletion_is_blocked and not spawning_delays and not changing_delays:
local_logger.debug("Removing the finalizer, thus allowing the actual deletion.")
finalizers.allow_deletion(body=body, patch=patch, finalizer=finalizer)
delays = list(spawning_delays) + list(changing_delays)
return (delays, changing_cause is not None)
def test_has_finalizers(expected, body):
result = is_deletion_blocked(body=body, finalizer='fin')
assert result == expected