K8S：分享一次“乌龙问题”（人为导致的无法正常删除命名空间）
问题背景
背景是这样的，我有一套测试用的K8S集群，发现无法正常删除命名空间了，一直处于Terminating状态，强制删除也不行。于是，再次手动创建了一个名为“test-b”的命名空间，同样也是不能正常删除。于是，展开了排查。不过，查到最后，发现是个毫无技术含量的“乌龙问题”。结果不重要，重要的是我想把这个过程分享一下。
排查过程
- 正常删除命名空间时，一直处于阻塞状态，只能Ctrl+C掉
[root@k8s-b-master?~]#?kubectl?delete?ns?test-b
namespace?"test-b"?deleted- 查看状态一直处于Terminating状态
[root@k8s-b-master?~]#?kubectl?get?ns
test-b????????????Terminating???18h- 尝试强制删除，也是一直处于阻塞状态，也只能Ctrl+C掉
[root@k8s-b-master?~]#?kubectl?delete?namespace?test-b?--grace-period=0?--force- 查看详细信息发现
[root@k8s-b-master?~]#?kubectl?describe?ns?test-b
Name:?????????test-b
Labels:???????kubernetes.io/metadata.name=test-b
Annotations:??<none>
Status:???????Terminating
Conditions:
??Type?????????????????????????????????????????Status??LastTransitionTime???????????????Reason??????????????????Message
??----?????????????????????????????????????????------??------------------???????????????------??????????????????-------
??NamespaceDeletionDiscoveryFailure????????????True????Fri,?05?May?2023?14:06:52?+0800??DiscoveryFailed?????????Discovery?failed?for?some?groups,?1?failing:?unable?to?retrieve?the?complete?list?of?server?APIs:?metrics.k8s.io/v1beta1:?the?server?is?currently?unable?to?handle?the?request
??NamespaceDeletionGroupVersionParsingFailure??False???Fri,?05?May?2023?14:06:52?+0800??ParsedGroupVersions?????All?legacy?kube?types?successfully?parsed
??NamespaceDeletionContentFailure??????????????False???Fri,?05?May?2023?14:06:52?+0800??ContentDeleted??????????All?content?successfully?deleted,?may?be?waiting?on?finalization
??NamespaceContentRemaining????????????????????False???Fri,?05?May?2023?14:06:52?+0800??ContentRemoved??????????All?content?successfully?removed
??NamespaceFinalizersRemaining?????????????????False???Fri,?05?May?2023?14:06:52?+0800??ContentHasNoFinalizers??All?content-preserving?finalizers?finished
No?resource?quota.
No?LimitRange?resource.问题出在这里：DiscoveryFailed：Discovery failed for some groups, 1 failing: unable to retrieve the complete list of server APIs: metrics.k8s.io/v1beta1: the server is currently unable to handle the request
难道API Server出问题了？于是继续排查。
- 检查API Server是否正常运行
[root@k8s-b-master?~]#?kubectl?get?componentstatus
Warning:?v1?ComponentStatus?is?deprecated?in?v1.19+
NAME?????????????????STATUS????MESSAGE?????????????????????????ERROR
controller-manager???Healthy???ok??????????????????????????????
etcd-0???????????????Healthy???{"health":"true","reason":""}???
scheduler????????????Healthy???ok??????????????????????????????从输出来看，controller-manager、scheduler和etcd集群都处于正常状态（Healthy）。
- 继续检查API Server的日志看看是否有错误或异常
#?获取API?Server?Pod的名称：
[root@k8s-b-master?~]#?kubectl?get?pods?-n?kube-system?-l?component=kube-apiserver?-o?name
pod/kube-apiserver-k8s-b-master
#?查看API?Server的日志：
[root@k8s-b-master?~]#?kubectl?get?pods?-n?kube-system?-l?component=kube-apiserver?-o?name
pod/kube-apiserver-k8s-b-master
[root@k8s-b-master?~]#?kubectl?logs?-n?kube-system?kube-apiserver-k8s-b-master
...
...
W0506?01:00:12.965627???????1?handler_proxy.go:105]?no?RequestInfo?found?in?the?context
E0506?01:00:12.965711???????1?controller.go:116]?loading?OpenAPI?spec?for?"v1beta1.metrics.k8s.io"?failed?with:?failed?to?retrieve?openAPI?spec,?http?error:?ResponseCode:?503,?Body:?service?unavailable
,?Header:?map[Content-Type:[text/plain;?charset=utf-8]?X-Content-Type-Options:[nosniff]]
I0506?01:00:12.965722???????1?controller.go:129]?OpenAPI?AggregationController:?action?for?item?v1beta1.metrics.k8s.io:?Rate?Limited?Requeue.
W0506?01:00:12.968678???????1?handler_proxy.go:105]?no?RequestInfo?found?in?the?context
E0506?01:00:12.968709???????1?controller.go:113]?loading?OpenAPI?spec?for?"v1beta1.metrics.k8s.io"?failed?with:?Error,?could?not?get?list?of?group?versions?for?APIService
I0506?01:00:12.968719???????1?controller.go:126]?OpenAPI?AggregationController:?action?for?item?v1beta1.metrics.k8s.io:?Rate?Limited?Requeue.
I0506?01:00:43.794546???????1?controller.go:616]?quota?admission?added?evaluator?for:?endpointslices.discovery.k8s.io
I0506?01:00:44.023629???????1?controller.go:616]?quota?admission?added?evaluator?for:?endpoints
W0506?01:01:12.965985???????1?handler_proxy.go:105]?no?RequestInfo?found?in?the?context
E0506?01:01:12.966062???????1?controller.go:116]?loading?OpenAPI?spec?for?"v1beta1.metrics.k8s.io"?failed?with:?failed?to?retrieve?openAPI?spec,?http?error:?ResponseCode:?503,?Body:?service?unavailable
,?Header:?map[Content-Type:[text/plain;?charset=utf-8]?X-Content-Type-Options:[nosniff]]
I0506?01:01:12.966069???????1?controller.go:129]?OpenAPI?AggregationController:?action?for?item?v1beta1.metrics.k8s.io:?Rate?Limited?Requeue.
W0506?01:01:12.969496???????1?handler_proxy.go:105]?no?RequestInfo?found?in?the?context
E0506?01:01:12.969527???????1?controller.go:113]?loading?OpenAPI?spec?for?"v1beta1.metrics.k8s.io"?failed?with:?Error,?could?not?get?list?of?group?versions?for?APIService
...
...
#?后面都是这样的Log
...
...从输出日志来看，问题似乎与metrics.k8s.io/v1beta1有关，这个API被用于收集Kubernetes集群的度量数据。可能是因为度量服务器(metrics-server)出现故障，无法满足API Server的请求，导致API Server无法处理请求。
- k8s默认是没有metrics-server组件的呀，还是看看：
[root@k8s-b-master?~]#?kubectl?get?pods?-n?kube-system?-l?k8s-app=metrics-server
No?resources?found?in?kube-system?namespace.kube-system命名空间中没有找到标签为k8s-app=metrics-server的Pod，这很正常呀，K8S本来就是默认没有安装Metrics Server 组件的，为什么现在又依赖了？
查到这里，我突然想起了前段时间部署过kube-prometheus，当时kube-state-metrics拉取镜像失败没有正常运行，因为是临时测试环境，后来就没管了，时间一长居然把这事给忘了。
于是看了一下，发现还真是：
[root@k8s-b-master?~]#?kubectl?get?pod?-n?monitoring
NAME???????????????????????????????????READY???STATUS?????????????RESTARTS???????AGE
alertmanager-main-0????????????????????2/2?????Running????????????14?(30m?ago)???5d19h
alertmanager-main-1????????????????????2/2?????Running????????????14?(29m?ago)???5d19h
alertmanager-main-2????????????????????2/2?????Running????????????14?(29m?ago)???5d19h
blackbox-exporter-69f4d86566-wn6q7?????3/3?????Running????????????21?(30m?ago)???5d19h
grafana-56c4977497-2rjmt???????????????1/1?????Running????????????7?(29m?ago)????5d19h
kube-state-metrics-56f8746666-lsps6????2/3?????ImagePullBackOff???14?(29m?ago)???5d19h?#?拉取镜像失败导致没有正常运行
node-exporter-d8c5k????????????????????2/2?????Running????????????14?(30m?ago)???5d19h
node-exporter-gvfx2????????????????????2/2?????Running????????????14?(30m?ago)???5d19h
node-exporter-gxccx????????????????????2/2?????Running????????????14?(29m?ago)???5d19h
node-exporter-h292z????????????????????2/2?????Running????????????14?(30m?ago)???5d19h
node-exporter-mztj6????????????????????2/2?????Running????????????14?(29m?ago)???5d19h
node-exporter-rvfz6????????????????????2/2?????Running????????????14?(29m?ago)???5d19h
node-exporter-twg9q????????????????????2/2?????Running????????????13?(29m?ago)???5d19h
prometheus-adapter-77f56b865b-76nzk????0/1?????ImagePullBackOff???0??????????????5d19h
prometheus-adapter-77f56b865b-wbcwl????0/1?????ImagePullBackOff???0??????????????5d19h
prometheus-k8s-0???????????????????????2/2?????Running????????????14?(30m?ago)???5d19h
prometheus-k8s-1???????????????????????2/2?????Running????????????14?(29m?ago)???5d19h
prometheus-operator-788dd7cb76-85zwj???2/2?????Running????????????14?(29m?ago)???5d19h反正也不用这套环境了，干它：
[root@k8s-b-master?~]#?kubectl?delete?-f?kube-prometheus-main/manifests/
[root@k8s-b-master?~]#?kubectl?delete?-f?kube-prometheus-main/manifests/setup/再次查看命名空间，test-b这个命名空间也随之能正常删除掉了，问题解决：
[root@k8s-b-master?~]#?kubectl?get?ns
NAME??????????????STATUS???AGE
default???????????Active???5d22h
kube-node-lease???Active???5d22h
kube-public???????Active???5d22h
kube-system???????Active???5d22h
[root@k8s-b-master?~]#?最后的觉悟
结合官方文档相关资料和自己平常的经验反思了一下这个事情，kube-state-metrics 组件是负责监控 K8S 集群的状态，并且它会定期获取集群内各个资源的指标数据，这些指标数据会被 Metrics Server 组件使用。当 kube-state-metrics 组件无法正常工作时，Metrics Server 组件就无法获取到指标数据，从而导致 Metrics Server 组件无法正常运行。在 K8S 集群中，很多组件都会使用 Metrics Server 组件提供的指标数据，例如 HPA、kubelet 等。如果 Metrics Server 组件无法正常运行，可能会导致其他组件出现问题，包括删除命名空间时提示错误。也就是说 Metrics Server 组件无法正常运行，导致了API Server组件在处理其它一些请求时可能会失败，从而发生了无法正常删除命名空间的情况。
本文系转载，前往查看
如有侵权，请联系?cloudcommunity@tencent.com 删除。
本文系转载，前往查看
如有侵权，请联系?cloudcommunity@tencent.com 删除。
评论
登录后参与评论
推荐阅读