以下代码将在第二个
ApiException 410 resource too old
上抛出 watch.stream()
:
# python3 -m venv venv
# source venv/bin/activate
# pip install 'kubernetes==23.3.0'
from kubernetes import client,config,watch
config.load_kube_config(context='my-eks-context')
v1 = client.CoreV1Api()
watcher = watch.Watch()
namespace = 'kube-system'
last_resource_version=0
# this watch will timeout in 5s to have a fast way to simulate a watch that need to be retried
for i in watcher.stream(v1.list_namespaced_pod, namespace, resource_version=last_resource_version, timeout_seconds=5):
print(i['object'].metadata.resource_version)
last_resource_version = i['object'].metadata.resource_version
# we retry the watch starting from the last resource version known
# but this will raise a kubernetes.client.exceptions.ApiException: (410)
# Reason: Expired: too old resource version: 379140622 (380367990)
for i in watcher.stream(v1.list_namespaced_pod, namespace, resource_version=last_resource_version, timeout_seconds=5):
print('second loop', i['object'].metadata.resource_version)
last_resource_version = i['object'].metadata.resource_version
如果客户端监视已断开连接,则该客户端可以从最后返回的资源版本开始新的监视
这就是我在上面的代码中的意图,它总是给出以下异常:
Traceback (most recent call last):
File "main.py", line 24, in <module>
File "/Users/rubelagu/git/python-kubernetes-client/venv/lib/python3.8/site-packages/kubernetes/watch/watch.py", line 182, in stream
raise client.rest.ApiException(
kubernetes.client.exceptions.ApiException: (410)
Reason: Expired: too old resource version: 379164133 (380432814)
我做错了什么?
似乎在对手表的初始响应中(来自 EKS 集群 1.21),事件可以按任何顺序返回。
我随后进行了两次间隔两秒的观察,它们包含相同的 30 个事件,但顺序完全不同。
因此,不能保证您看到的最后一个资源版本实际上是最后一个资源版本,也不能保证您可以从该版本恢复
resourceVersion
/resource_version
。另外,您也不允许按 resourceVersion
对这些事件进行排序/整理,因为资源版本语义的 kubernetes 文档明确指出:
资源版本必须被视为不透明 [...]您不得假设资源版本是数字或可整理的。
您必须通过捕获
resource too old exception
并在不指定资源版本的情况下重试来解决这一问题,请参阅下面的示例:
from kubernetes import client,config,watch
from kubernetes.client.exceptions import ApiException
config.load_kube_config(context='eks-prod')
v1 = client.CoreV1Api()
# v1 = config.new_client_from_config(context="eks-prod").CoreV1Api()
watcher = watch.Watch()
namespace = 'my-namespace'
def list_pods(resource_version=None):
print('start watch from resource version: ', str(resource_version))
try:
for i in watcher.stream(v1.list_namespaced_pod, namespace, resource_version=resource_version, timeout_seconds=2):
print(i['object'].metadata.resource_version)
last_resource_version = i['object'].metadata.resource_version
except ApiException as e:
if e.status == 410: # Resource too old
return list_pods(resource_version=None)
else:
raise
return last_resource_version
last_resource_version = list_pods() # creates a watch for 2 seconds only, returns the last known resource version
print('last_resource_version', last_resource_version)
list_pods(last_resource_version) # we try to resume from last know resource version, if that fails it will resume from resource version None