mirror of
https://github.com/ansible-collections/kubernetes.core.git
synced 2026-03-27 05:43:02 +00:00
Add new waiter (#306)
Add new waiter SUMMARY This refactors the waiter logic from common.py into a separate module. ISSUE TYPE COMPONENT NAME ADDITIONAL INFORMATION Reviewed-by: None <None> Reviewed-by: Alina Buzachis <None> Reviewed-by: None <None>
This commit is contained in:
Mike Graves
204
plugins/module_utils/k8s/waiter.py
Normal file
204
plugins/module_utils/k8s/waiter.py
Normal file
@@ -0,0 +1,204 @@
|
||||
import time
|
||||
from functools import partial
|
||||
from typing import Any, Callable, Dict, Iterator, List, Optional, Tuple, Union
|
||||
|
||||
from ansible.module_utils.parsing.convert_bool import boolean
|
||||
|
||||
try:
|
||||
from kubernetes.dynamic.exceptions import NotFoundError
|
||||
from kubernetes.dynamic.resource import Resource, ResourceField, ResourceInstance
|
||||
except ImportError:
|
||||
# These are defined only for the sake of Ansible's checked import requirement
|
||||
Resource = Any # type: ignore
|
||||
ResourceInstance = Any # type: ignore
|
||||
pass
|
||||
|
||||
|
||||
def deployment_ready(deployment: ResourceInstance) -> bool:
|
||||
# FIXME: frustratingly bool(deployment.status) is True even if status is empty
|
||||
# Furthermore deployment.status.availableReplicas == deployment.status.replicas == None if status is empty
|
||||
# deployment.status.replicas is None is perfectly ok if desired replicas == 0
|
||||
# Scaling up means that we also need to check that we're not in a
|
||||
# situation where status.replicas == status.availableReplicas
|
||||
# but spec.replicas != status.replicas
|
||||
return bool(
|
||||
deployment.status
|
||||
and deployment.spec.replicas == (deployment.status.replicas or 0)
|
||||
and deployment.status.availableReplicas == deployment.status.replicas
|
||||
and deployment.status.observedGeneration == deployment.metadata.generation
|
||||
and not deployment.status.unavailableReplicas
|
||||
)
|
||||
|
||||
|
||||
def pod_ready(pod: ResourceInstance) -> bool:
|
||||
return bool(
|
||||
pod.status
|
||||
and pod.status.containerStatuses is not None
|
||||
and all(container.ready for container in pod.status.containerStatuses)
|
||||
)
|
||||
|
||||
|
||||
def daemonset_ready(daemonset: ResourceInstance) -> bool:
|
||||
return bool(
|
||||
daemonset.status
|
||||
and daemonset.status.desiredNumberScheduled is not None
|
||||
and daemonset.status.updatedNumberScheduled
|
||||
== daemonset.status.desiredNumberScheduled
|
||||
and daemonset.status.numberReady == daemonset.status.desiredNumberScheduled
|
||||
and daemonset.status.observedGeneration == daemonset.metadata.generation
|
||||
and not daemonset.status.unavailableReplicas
|
||||
)
|
||||
|
||||
|
||||
def statefulset_ready(statefulset: ResourceInstance) -> bool:
|
||||
return bool(
|
||||
statefulset.status
|
||||
and statefulset.spec.updateStrategy.type == "RollingUpdate"
|
||||
and statefulset.status.observedGeneration
|
||||
== (statefulset.metadata.generation or 0)
|
||||
and statefulset.status.updateRevision == statefulset.status.currentRevision
|
||||
and statefulset.status.updatedReplicas == statefulset.spec.replicas
|
||||
and statefulset.status.readyReplicas == statefulset.spec.replicas
|
||||
and statefulset.status.replicas == statefulset.spec.replicas
|
||||
)
|
||||
|
||||
|
||||
def custom_condition(condition: Dict, resource: ResourceInstance) -> bool:
|
||||
if not resource.status or not resource.status.conditions:
|
||||
return False
|
||||
matches = [x for x in resource.status.conditions if x.type == condition["type"]]
|
||||
if not matches:
|
||||
return False
|
||||
# There should never be more than one condition of a specific type
|
||||
match: ResourceField = matches[0]
|
||||
if match.status == "Unknown":
|
||||
if match.status == condition["status"]:
|
||||
if "reason" not in condition:
|
||||
return True
|
||||
if condition["reason"]:
|
||||
return match.reason == condition["reason"]
|
||||
return False
|
||||
status = True if match.status == "True" else False
|
||||
if status == boolean(condition["status"], strict=False):
|
||||
if condition.get("reason"):
|
||||
return match.reason == condition["reason"]
|
||||
return True
|
||||
return False
|
||||
|
||||
|
||||
def resource_absent(resource: ResourceInstance) -> bool:
|
||||
return not exists(resource)
|
||||
|
||||
|
||||
def exists(resource: Optional[ResourceInstance]) -> bool:
|
||||
"""Simple predicate to check for existence of a resource.
|
||||
|
||||
While a List type resource technically always exists, this will only return
|
||||
true if the List contains items."""
|
||||
return bool(resource) and not empty_list(resource)
|
||||
|
||||
|
||||
RESOURCE_PREDICATES = {
|
||||
"DaemonSet": daemonset_ready,
|
||||
"Deployment": deployment_ready,
|
||||
"Pod": pod_ready,
|
||||
"StatefulSet": statefulset_ready,
|
||||
}
|
||||
|
||||
|
||||
def empty_list(resource: ResourceInstance) -> bool:
|
||||
return resource.kind.endswith("List") and not resource.get("items")
|
||||
|
||||
|
||||
def clock(total: int, interval: int) -> Iterator[int]:
|
||||
start = time.monotonic()
|
||||
yield 0
|
||||
while (time.monotonic() - start) < total:
|
||||
time.sleep(interval)
|
||||
yield int(time.monotonic() - start)
|
||||
|
||||
|
||||
class Waiter:
|
||||
def __init__(
|
||||
self, client, resource: Resource, predicate: Callable[[ResourceInstance], bool]
|
||||
):
|
||||
self.client = client
|
||||
self.resource = resource
|
||||
self.predicate = predicate
|
||||
|
||||
def wait(
|
||||
self,
|
||||
definition: Dict,
|
||||
timeout: int,
|
||||
sleep: int,
|
||||
label_selectors: Optional[List[str]] = None,
|
||||
) -> Tuple[bool, Optional[Dict], int]:
|
||||
params = {
|
||||
"name": definition["metadata"].get("name"),
|
||||
"namespace": definition["metadata"].get("namespace"),
|
||||
}
|
||||
if label_selectors:
|
||||
params["label_selector"] = ",".join(label_selectors)
|
||||
instance: Optional[Dict] = None
|
||||
response = None
|
||||
elapsed = 0
|
||||
for i in clock(timeout, sleep):
|
||||
elapsed = i
|
||||
try:
|
||||
response = self.client.get(self.resource, **params)
|
||||
except NotFoundError:
|
||||
pass
|
||||
if self.predicate(response):
|
||||
break
|
||||
if response:
|
||||
instance = response.to_dict()
|
||||
return self.predicate(response), instance, elapsed
|
||||
|
||||
|
||||
class DummyWaiter:
|
||||
"""A no-op waiter that simply returns the item being waited on.
|
||||
|
||||
No API call will be made with this waiter; the function returns
|
||||
immediately. This waiter is useful for waiting on resource instances in
|
||||
check mode, for example.
|
||||
"""
|
||||
|
||||
def wait(
|
||||
self,
|
||||
definition: Dict,
|
||||
timeout: int,
|
||||
sleep: int,
|
||||
label_selectors: Optional[List[str]] = None,
|
||||
) -> Tuple[bool, Optional[Dict], int]:
|
||||
return True, definition, 0
|
||||
|
||||
|
||||
# The better solution would be typing.Protocol, but this is only in 3.8+
|
||||
SupportsWait = Union[Waiter, DummyWaiter]
|
||||
|
||||
|
||||
def get_waiter(
|
||||
client,
|
||||
resource: Resource,
|
||||
state: str = "present",
|
||||
condition: Optional[Dict] = None,
|
||||
check_mode: Optional[bool] = False,
|
||||
) -> SupportsWait:
|
||||
"""Create a Waiter object based on the specified resource.
|
||||
|
||||
This is a convenience method for creating a waiter from a resource.
|
||||
Based on the arguments and the kind of resource, an appropriate waiter
|
||||
will be returned. A waiter can also be created directly, of course.
|
||||
"""
|
||||
if check_mode:
|
||||
return DummyWaiter()
|
||||
if state == "present":
|
||||
if condition:
|
||||
predicate: Callable[[ResourceInstance], bool] = partial(
|
||||
custom_condition, condition
|
||||
)
|
||||
else:
|
||||
predicate = RESOURCE_PREDICATES.get(resource.kind, exists)
|
||||
else:
|
||||
predicate = resource_absent
|
||||
return Waiter(client, resource, predicate)
|
||||
Reference in New Issue
Block a user