def detect_cause(event: Mapping,
requires_finalizer: bool = True,
**kwargs) -> Cause:
"""
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.
"""
diff = kwargs.get('diff')
body = event['object']
initial = event[
'type'] is None # special value simulated by us in kopf.reactor.watching.
# The object was really deleted from the cluster. But we do not care anymore.
if event['type'] == 'DELETED':
return Cause(event=GONE, body=body, initial=initial, **kwargs)
# The finalizer has been just removed. We are fully done.
if finalizers.is_deleted(body) and not finalizers.has_finalizers(body):
return Cause(event=FREE, body=body, initial=initial, **kwargs)
if finalizers.is_deleted(body):
return Cause(event=DELETE, body=body, initial=initial, **kwargs)
# For a fresh new object, first block it from accidental deletions without our permission.
# The actual handler will be called on the next call.
# Only return this cause if the resource requires finalizers to be added.
if requires_finalizer and not finalizers.has_finalizers(body):
return Cause(event=ACQUIRE, body=body, initial=initial, **kwargs)
# Check whether or not the resource has finalizers, but doesn't require them. If this is
# the case, then a resource may not be able to be deleted completely as finalizers may
# not be removed by the operator under normal operation. We remove the finalizers first,
# and any handler that should be called will be done on the next call.
if not requires_finalizer and finalizers.has_finalizers(body):
return Cause(event=RELEASE, body=body, initial=initial, **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.
if not lastseen.has_state(body):
return Cause(event=CREATE, body=body, initial=initial, **kwargs)
# Cases with no state changes are usually ignored (NOOP). But for the "None" events,
# as simulated for the initial listing, we call the resuming handlers (e.g. threads/tasks).
if not diff and initial:
return Cause(event=RESUME, body=body, initial=initial, **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 Cause(event=NOOP, body=body, initial=initial, **kwargs)
# And what is left, is the update operation on one of the useful fields of the existing object.
return Cause(event=UPDATE, body=body, initial=initial, **kwargs)
def detect_cause(event: Mapping, **kwargs) -> Cause:
"""
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.
"""
body = event['object']
initial = event[
'type'] is None # special value simulated by us in kopf.reactor.watching.
# The object was really deleted from the cluster. But we do not care anymore.
if event['type'] == 'DELETED':
return Cause(event=GONE, body=body, initial=initial, **kwargs)
# The finalizer has been just removed. We are fully done.
if finalizers.is_deleted(body) and not finalizers.has_finalizers(body):
return Cause(event=FREE, body=body, initial=initial, **kwargs)
if finalizers.is_deleted(body):
return Cause(event=DELETE, body=body, initial=initial, **kwargs)
# For a fresh new object, first block it from accidental deletions without our permission.
# The actual handler will be called on the next call.
if not finalizers.has_finalizers(body):
return Cause(event=NEW, body=body, initial=initial, **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.
if not lastseen.has_state(body):
return Cause(event=CREATE, body=body, initial=initial, **kwargs)
# Cases with no state changes are usually ignored (NOOP). But for the "None" events,
# as simulated for the initial listing, we call the resuming handlers (e.g. threads/tasks).
if not lastseen.is_state_changed(body) and initial:
return Cause(event=RESUME, body=body, initial=initial, **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 lastseen.is_state_changed(body):
return Cause(event=NOOP, body=body, initial=initial, **kwargs)
# And what is left, is the update operation on one of the useful fields of the existing object.
old, new, diff = lastseen.get_state_diffs(body)
return Cause(event=UPDATE,
body=body,
initial=initial,
diff=diff,
old=old,
new=new,
**kwargs)
def detect_resource_changing_cause(
*,
event: bodies.Event,
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).
body = event['object']
kwargs.update(body=body, 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 event['type'] == 'DELETED':
return ResourceChangingCause(reason=Reason.GONE, **kwargs)
# The finalizer has been just removed. We are fully done.
if finalizers.is_deleted(body) and not finalizers.has_finalizers(body):
return ResourceChangingCause(reason=Reason.FREE, **kwargs)
if finalizers.is_deleted(body):
return ResourceChangingCause(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 not lastseen.has_essence_stored(body):
kwargs['initial'] = False
return ResourceChangingCause(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 ResourceChangingCause(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 ResourceChangingCause(reason=Reason.NOOP, **kwargs)
# And what is left, is the update operation on one of the useful fields of the existing object.
return ResourceChangingCause(reason=Reason.UPDATE, **kwargs)
async def custom_object_handler(
lifecycle: Callable,
registry: registries.BaseRegistry,
resource: registries.Resource,
event: dict,
freeze: asyncio.Event,
) -> 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.
"""
etyp = event['type'] # e.g. ADDED, MODIFIED, DELETED.
body = event['object']
# Each object has its own prefixed logger, to distinguish parallel handling.
logger = ObjectLogger(
logging.getLogger(__name__),
extra=dict(
namespace=body.get('metadata', {}).get('namespace', 'default'),
name=body.get('metadata',
{}).get('name',
body.get('metadata', {}).get('uid', None)),
))
# Object patch accumulator. Populated by the methods. Applied in the end of the handler.
patch = {}
delay = None
# If the global freeze is set for the processing (i.e. other operator overrides), do nothing.
if freeze.is_set():
logger.debug("Ignoring the events due to freeze.")
# The object was really deleted from the cluster. But we do not care anymore.
elif etyp == 'DELETED':
logger.debug("Deleted, really deleted, and we are notified.")
# The finalizer has been just removed. We are fully done.
elif finalizers.is_deleted(body) and not finalizers.has_finalizers(body):
logger.debug(
"Deletion event, but we are done with it, but we do not care.")
elif finalizers.is_deleted(body):
logger.debug("Deletion event: %r", body)
cause = Cause(resource=resource,
event=registries.DELETE,
body=body,
patch=patch,
logger=logger)
try:
await execute(lifecycle=lifecycle, registry=registry, cause=cause)
except HandlerChildrenRetry as e:
# on the top-level, no patches -- it is pre-patched.
delay = e.delay
else:
logger.info(f"All handlers succeeded for deletion.")
events.info(cause.body,
reason='Success',
message=f"All handlers succeeded for deletion.")
logger.debug(
"Removing the finalizer, thus allowing the actual deletion.")
finalizers.remove_finalizers(body=body, patch=patch)
# For a fresh new object, first block it from accidental deletions without our permission.
# The actual handler will be called on the next call.
elif not finalizers.has_finalizers(body):
logger.debug("First appearance: %r", body)
logger.debug(
"Adding the finalizer, thus preventing the actual deletion.")
finalizers.append_finalizers(body=body, patch=patch)
# For the 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.
elif not lastseen.has_state(body):
logger.debug("Creation event: %r", body)
cause = Cause(resource=resource,
event=registries.CREATE,
body=body,
patch=patch,
logger=logger)
try:
await execute(lifecycle=lifecycle, registry=registry, cause=cause)
except HandlerChildrenRetry as e:
# on the top-level, no patches -- it is pre-patched.
delay = e.delay
else:
logger.info(f"All handlers succeeded for creation.")
events.info(cause.body,
reason='Success',
message=f"All handlers succeeded for creation.")
status.purge_progress(body=body, patch=patch)
lastseen.refresh_state(body=body, patch=patch)
# The previous step triggers one more patch operation without actual change. Ignore it.
# Either the last-seen state or the status field has changed.
elif not lastseen.is_state_changed(body):
pass
# And what is left, is the update operation on one of the useful fields of the existing object.
else:
old, new, diff = lastseen.get_state_diffs(body)
logger.debug("Update event: %r", diff)
cause = Cause(resource=resource,
event=registries.UPDATE,
body=body,
patch=patch,
logger=logger,
old=old,
new=new,
diff=diff)
try:
await execute(lifecycle=lifecycle, registry=registry, cause=cause)
except HandlerChildrenRetry as e:
# on the top-level, no patches -- it is pre-patched.
delay = e.delay
else:
logger.info(f"All handlers succeeded for update.")
events.info(cause.body,
reason='Success',
message=f"All handlers succeeded for update.")
status.purge_progress(body=body, patch=patch)
lastseen.refresh_state(body=body, patch=patch)
# Provoke a dummy change to trigger the reactor after sleep.
# TODO: reimplement via the handler delayed statuses properly.
if delay and not patch:
patch.setdefault('kopf',
{})['dummy'] = datetime.datetime.utcnow().isoformat()
# Whatever was done, apply the accumulated changes to the object.
# But only once, to reduce the number of API calls and the generated irrelevant events.
if patch:
logger.debug("Patching with: %r", patch)
patching.patch_obj(resource=resource, patch=patch, body=body)
# Sleep strictly after patching, never before -- to keep the status proper.
if delay:
logger.info(f"Sleeping for {delay} seconds for the delayed handlers.")
await asyncio.sleep(delay)
async def process_resource_changing_cause(
lifecycle: lifecycles.LifeCycleFn,
registry: registries.OperatorRegistry,
memory: containers.ResourceMemory,
cause: causation.ResourceChangingCause,
) -> Optional[float]:
"""
Handle a detected cause, as part of the bigger handler routine.
"""
logger = cause.logger
patch = cause.patch # TODO get rid of this alias
body = cause.body # TODO get rid of this alias
delay = None
done = None
skip = None
resource_changing_handlers = registry.resource_changing_handlers[
cause.resource]
requires_finalizer = resource_changing_handlers.requires_finalizer(
cause=cause)
has_finalizer = finalizers.has_finalizers(body=cause.body)
if requires_finalizer and not has_finalizer:
logger.debug(
"Adding the finalizer, thus preventing the actual deletion.")
finalizers.append_finalizers(body=body, patch=patch)
return None
if not requires_finalizer and has_finalizer:
logger.debug(
"Removing the finalizer, as there are no handlers requiring it.")
finalizers.remove_finalizers(body=body, patch=patch)
return None
# Regular causes invoke the handlers.
if cause.reason in causation.HANDLER_REASONS:
title = causation.TITLES.get(cause.reason, repr(cause.reason))
logger.debug(f"{title.capitalize()} event: %r", body)
if cause.diff and cause.old is not None and cause.new is not None:
logger.debug(f"{title.capitalize()} diff: %r", cause.diff)
handlers = registry.resource_changing_handlers[
cause.resource].get_handlers(cause=cause)
state = states.State.from_body(body=cause.body, handlers=handlers)
if handlers:
outcomes = await handling.execute_handlers_once(
lifecycle=lifecycle,
handlers=handlers,
cause=cause,
state=state,
)
state = state.with_outcomes(outcomes)
state.store(patch=cause.patch)
states.deliver_results(outcomes=outcomes, patch=cause.patch)
if state.done:
logger.info(f"All handlers succeeded for {title}.")
state.purge(patch=cause.patch, body=cause.body)
done = state.done
delay = state.delay
else:
skip = True
# Regular causes also do some implicit post-handling when all handlers are done.
if done or skip:
extra_fields = registry.resource_changing_handlers[
cause.resource].get_extra_fields()
lastseen.refresh_essence(body=body,
patch=patch,
extra_fields=extra_fields)
if cause.reason == causation.Reason.DELETE:
logger.debug(
"Removing the finalizer, thus allowing the actual deletion.")
finalizers.remove_finalizers(body=body, patch=patch)
# Once all handlers have succeeded at least once for any reason, or if there were none,
# prevent further resume-handlers (which otherwise happens on each watch-stream re-listing).
memory.fully_handled_once = True
# Informational causes just print the log lines.
if cause.reason == causation.Reason.GONE:
logger.debug("Deleted, really deleted, and we are notified.")
if cause.reason == causation.Reason.FREE:
logger.debug(
"Deletion event, but we are done with it, and we do not care.")
if cause.reason == causation.Reason.NOOP:
logger.debug(
"Something has changed, but we are not interested (the essence is the same)."
)
# The delay is then consumed by the main handling routine (in different ways).
return delay
def test_has_finalizers(expected, body):
result = has_finalizers(body=body)
assert result == expected
