def detect_resource_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,
) -> ResourceChangingCause:
"""
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 ResourceChangingCause(reason=handlers.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 ResourceChangingCause(reason=handlers.Reason.FREE, **kwargs)
if deletion_is_ongoing:
return ResourceChangingCause(reason=handlers.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 ResourceChangingCause(reason=handlers.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 ResourceChangingCause(reason=handlers.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 ResourceChangingCause(reason=handlers.Reason.NOOP, **kwargs)
# And what is left, is the update operation on one of the useful fields of the existing object.
return ResourceChangingCause(reason=handlers.Reason.UPDATE, **kwargs)
def test_has_finalizers(expected, body):
result = is_deletion_blocked(body=body, finalizer='fin')
assert result == expected
async def process_resource_causes(
lifecycle: lifecycles.LifeCycleFn,
indexers: indexing.OperatorIndexers,
registry: registries.OperatorRegistry,
settings: configuration.OperatorSettings,
resource: references.Resource,
raw_event: bodies.RawEvent,
body: bodies.Body,
patch: patches.Patch,
logger: loggers.ObjectLogger,
memory: containers.ResourceMemory,
) -> Tuple[Collection[float], bool]:
finalizer = settings.persistence.finalizer
extra_fields = (
# NB: indexing handlers are useless here, they are handled on their own.
registry._resource_watching.get_extra_fields(resource=resource)
| registry._resource_changing.get_extra_fields(resource=resource)
| registry._resource_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.
resource_watching_cause = causation.detect_resource_watching_cause(
raw_event=raw_event,
resource=resource,
indices=indexers.indices,
logger=logger,
patch=patch,
body=body,
memo=memory.memo,
) if registry._resource_watching.has_handlers(resource=resource) else None
resource_spawning_cause = causation.detect_resource_spawning_cause(
resource=resource,
indices=indexers.indices,
logger=logger,
patch=patch,
body=body,
memo=memory.memo,
reset=bool(
diff), # only essential changes reset idling, not every event
) if registry._resource_spawning.has_handlers(resource=resource) else None
resource_changing_cause = causation.detect_resource_changing_cause(
finalizer=finalizer,
raw_event=raw_event,
resource=resource,
indices=indexers.indices,
logger=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._resource_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 (resource_changing_cause is not None
and not registry._resource_changing.prematch(
cause=resource_changing_cause)):
resource_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 = (
(resource_spawning_cause is not None
and registry._resource_spawning.requires_finalizer(
cause=resource_spawning_cause,
excluded=memory.forever_stopped,
)) or (resource_changing_cause is not None
and registry._resource_changing.requires_finalizer(
cause=resource_changing_cause, )))
if deletion_must_be_blocked and not deletion_is_blocked and not deletion_is_ongoing:
logger.debug(
"Adding the finalizer, thus preventing the actual deletion.")
finalizers.block_deletion(body=body, patch=patch, finalizer=finalizer)
resource_changing_cause = None # prevent further high-level processing this time
if not deletion_must_be_blocked and deletion_is_blocked:
logger.debug(
"Removing the finalizer, as there are no handlers requiring it.")
finalizers.allow_deletion(body=body, patch=patch, finalizer=finalizer)
resource_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 resource_watching_cause is not None:
await process_resource_watching_cause(
lifecycle=lifecycles.all_at_once,
registry=registry,
settings=settings,
cause=resource_watching_cause,
)
resource_spawning_delays: Collection[float] = []
if resource_spawning_cause is not None:
resource_spawning_delays = await process_resource_spawning_cause(
registry=registry,
settings=settings,
memory=memory,
cause=resource_spawning_cause,
)
resource_changing_delays: Collection[float] = []
if resource_changing_cause is not None:
resource_changing_delays = await process_resource_changing_cause(
lifecycle=lifecycle,
registry=registry,
settings=settings,
memory=memory,
cause=resource_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 resource_spawning_delays \
and not resource_changing_delays:
logger.debug(
"Removing the finalizer, thus allowing the actual deletion.")
finalizers.allow_deletion(body=body, patch=patch, finalizer=finalizer)
delays = list(resource_spawning_delays) + list(resource_changing_delays)
return (delays, resource_changing_cause is not None)
async def process_resource_event(
lifecycle: lifecycles.LifeCycleFn,
registry: registries.OperatorRegistry,
settings: configuration.OperatorSettings,
memories: containers.ResourceMemories,
resource: resources.Resource,
raw_event: bodies.RawEvent,
replenished: asyncio.Event,
event_queue: posting.K8sEventQueue,
) -> None:
"""
Handle a single custom object low-level watch-event.
Convert the low-level events, as provided by the watching/queueing tasks,
to the high-level causes, and then call the cause-handling logic.
All the internally provoked changes are intercepted, do not create causes,
and therefore do not call the handling logic.
"""
finalizer = settings.persistence.finalizer
# Recall what is stored about that object. Share it in little portions with the consumers.
# And immediately forget it if the object is deleted from the cluster (but keep in memory).
raw_type, raw_body = raw_event['type'], raw_event['object']
memory = await memories.recall(raw_body,
noticed_by_listing=raw_type is None)
if memory.live_fresh_body is not None:
memory.live_fresh_body._replace_with(raw_body)
if raw_type == 'DELETED':
await memories.forget(raw_body)
# Convert to a heavy mapping-view wrapper only now, when heavy processing begins.
# Raw-event streaming, queueing, and batching use regular lightweight dicts.
# Why here? 1. Before it splits into multiple causes & handlers for the same object's body;
# 2. After it is batched (queueing); 3. While the "raw" parsed JSON is still known;
# 4. Same as where a patch object of a similar wrapping semantics is created.
body = memory.live_fresh_body if memory.live_fresh_body is not None else bodies.Body(
raw_body)
patch = patches.Patch()
# Each object has its own prefixed logger, to distinguish parallel handling.
logger = logging_engine.ObjectLogger(body=body, settings=settings)
posting.event_queue_loop_var.set(asyncio.get_running_loop())
posting.event_queue_var.set(
event_queue) # till the end of this object's task.
extra_fields = registry.resource_changing_handlers[
resource].get_extra_fields()
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.
resource_watching_cause = causation.detect_resource_watching_cause(
raw_event=raw_event,
resource=resource,
logger=logger,
patch=patch,
body=body,
memo=memory.memo,
) if registry.resource_watching_handlers[resource] else None
resource_spawning_cause = causation.detect_resource_spawning_cause(
resource=resource,
logger=logger,
patch=patch,
body=body,
memo=memory.memo,
reset=bool(
diff), # only essential changes reset idling, not every event
) if registry.resource_spawning_handlers[resource] else None
resource_changing_cause = causation.detect_resource_changing_cause(
finalizer=finalizer,
raw_event=raw_event,
resource=resource,
logger=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.resource_changing_handlers[resource] else 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 = (
(resource_spawning_cause is not None
and registry.resource_spawning_handlers[resource].requires_finalizer(
cause=resource_spawning_cause,
excluded=memory.forever_stopped,
)) or
(resource_changing_cause is not None
and registry.resource_changing_handlers[resource].requires_finalizer(
cause=resource_changing_cause, )))
if deletion_must_be_blocked and not deletion_is_blocked and not deletion_is_ongoing:
logger.debug(
"Adding the finalizer, thus preventing the actual deletion.")
finalizers.block_deletion(body=body, patch=patch, finalizer=finalizer)
resource_changing_cause = None # prevent further high-level processing this time
if not deletion_must_be_blocked and deletion_is_blocked:
logger.debug(
"Removing the finalizer, as there are no handlers requiring it.")
finalizers.allow_deletion(body=body, patch=patch, finalizer=finalizer)
resource_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 resource_watching_cause is not None:
await process_resource_watching_cause(
lifecycle=lifecycles.all_at_once,
registry=registry,
settings=settings,
cause=resource_watching_cause,
)
resource_spawning_delays: Collection[float] = []
if resource_spawning_cause is not None:
resource_spawning_delays = await process_resource_spawning_cause(
registry=registry,
settings=settings,
memory=memory,
cause=resource_spawning_cause,
)
resource_changing_delays: Collection[float] = []
if resource_changing_cause is not None:
resource_changing_delays = await process_resource_changing_cause(
lifecycle=lifecycle,
registry=registry,
settings=settings,
memory=memory,
cause=resource_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 resource_spawning_delays \
and not resource_changing_delays:
logger.debug(
"Removing the finalizer, thus allowing the actual deletion.")
finalizers.allow_deletion(body=body, patch=patch, finalizer=finalizer)
# Whatever was done, apply the accumulated changes to the object, or sleep-n-touch for delays.
# But only once, to reduce the number of API calls and the generated irrelevant events.
# And only if the object is at least supposed to exist (not "GONE"), even if actually does not.
if raw_event['type'] != 'DELETED':
await apply_reaction_outcomes(
settings=settings,
resource=resource,
body=body,
patch=patch,
logger=logger,
delays=list(resource_spawning_delays) +
list(resource_changing_delays),
replenished=replenished,
)