Kubernetes 常用命令

Master节点常用命令

重启apiserver

# 获得 apiserver 的 pod 名字
export apiserver_pods=$(kubectl get pods --selector=component=kube-apiserver -n kube-system --output=jsonpath={.items..metadata.name})
# 删除 apiserver 的 pod
kubectl delete pod $apiserver_pods -n kube-system

查看所有的pod

kubectl get pods -A

查看pod启动日志

kubectl --namespace=calico-system  describe pod  tigera-operator-5dc8b759d9-5gnwt

• --namespace 指定命名空间
• describe pod 后面跟pod的name

删除pod

kubectl delete pod kubernetes-dashboard-5676d8b865-98ht9 -n kubernetes-dashboard

• -n 命名空间
• --grace-period=0 --force 强制删除

查看 namespace 下面所有的资源

kubectl api-resources -o name --verbs=list --namespaced | xargs -n 1 kubectl get --show-kind --ignore-not-found -n {namespace}

删除 namespace 下面所有的资源（慎重）

kubectl delete all --all -n {namespace}

当然也可以删除 namespace 来删除所有资源

kubectl delete ns {namespace}

有时候删除资源会出现卡住，可能是 kubernetes 正在处理，也可能是该资源是其它资源的依赖，导致无法删除
有时候删除资源会出现长时间处于 terminating 状态，可以使用 --force --grace-period=0 （不建议）

kubectl delete po xxx --force --grace-period=0

常见问题

1. k8s删除Terminating状态的命名空间

1. 查看命名空间

[root@kubernetes-master-1 kubernetes]#kubectl  get ns 
NAME                   STATUS        AGE
calico-apiserver       Active        2d18h
calico-system          Active        2d18h
default                Active        3d14h
kube-node-lease        Active        3d14h
kube-public            Active        3d14h
kube-system            Active        3d14h
kubernetes-dashboard   Terminating   2d17h
tigera-operator        Active        2d18h

发现kubernetes-dashboard一直处于Terminating 状态。无法删除命名空间！！

2.解决方法

查看kubesphere-system的namespace描述

kubectl get ns kubernetes-dashboard  -o json > kubernetes-dashboard.json

编辑json文件，删除spec字段的内存，因为k8s集群时需要认证的。

vi kubesphere-system.json

将

"spec": {
        "finalizers": [
            "kubernetes"
        ]
    },

更改为：

"spec": {
    
  },

新开一个窗口运行kubectl proxy跑一个API代理在本地的8081端口

# kubectl proxy --port=8081
Starting to serve on 127.0.0.1:8081

最后运行curl命令进行删除

curl -k -H "Content-Type:application/json" -X PUT --data-binary @kubernetes-dashboard.json http://127.0.0.1:8081/api/v1/namespaces/kubernetes-dashboard/finalize

注意：命令中的kubernetes-dashboard就是命名空间。

调用成功输出：

[root@kubernetes-master-1 kubernetes]# curl -k -H "Content-Type:application/json" -X PUT --data-binary @kubesphere-dashboard.json http://127.0.0.1:8081/api/v1/namespaces/kubernetes-dashboard/finalize
{
  "kind": "Namespace",
  "apiVersion": "v1",
  "metadata": {
    "name": "kubernetes-dashboard",
    "uid": "31b1c662-663b-42e1-a6b8-9abd1cd96911",
    "resourceVersion": "54597",
    "creationTimestamp": "2022-07-15T08:35:55Z",
    "deletionTimestamp": "2022-07-18T01:42:39Z",
    "labels": {
      "kubernetes.io/metadata.name": "kubernetes-dashboard"
    },
    "annotations": {
      "kubectl.kubernetes.io/last-applied-configuration": "{\"apiVersion\":\"v1\",\"kind\":\"Namespace\",\"metadata\":{\"annotations\":{},\"name\":\"kubernetes-dashboard\"}}\n"
    },
    "managedFields": [
      {
        "manager": "kubectl-client-side-apply",
        "operation": "Update",
        "apiVersion": "v1",
        "time": "2022-07-15T08:35:55Z",
        "fieldsType": "FieldsV1",
        "fieldsV1": {
          "f:metadata": {
            "f:annotations": {
              ".": {},
              "f:kubectl.kubernetes.io/last-applied-configuration": {}
            },
            "f:labels": {
              ".": {},
              "f:kubernetes.io/metadata.name": {}
            }
          }
        }
      },
      {
        "manager": "kube-controller-manager",
        "operation": "Update",
        "apiVersion": "v1",
        "time": "2022-07-18T01:42:45Z",
        "fieldsType": "FieldsV1",
        "fieldsV1": {
          "f:status": {
            "f:conditions": {
              ".": {},
              "k:{\"type\":\"NamespaceContentRemaining\"}": {
                ".": {},
                "f:lastTransitionTime": {},
                "f:message": {},
                "f:reason": {},
                "f:status": {},
                "f:type": {}
              },
              "k:{\"type\":\"NamespaceDeletionContentFailure\"}": {
                ".": {},
                "f:lastTransitionTime": {},
                "f:message": {},
                "f:reason": {},
                "f:status": {},
                "f:type": {}
              },
              "k:{\"type\":\"NamespaceDeletionDiscoveryFailure\"}": {
                ".": {},
                "f:lastTransitionTime": {},
                "f:message": {},
                "f:reason": {},
                "f:status": {},
                "f:type": {}
              },
              "k:{\"type\":\"NamespaceDeletionGroupVersionParsingFailure\"}": {
                ".": {},
                "f:lastTransitionTime": {},
                "f:message": {},
                "f:reason": {},
                "f:status": {},
                "f:type": {}
              },
              "k:{\"type\":\"NamespaceFinalizersRemaining\"}": {
                ".": {},
                "f:lastTransitionTime": {},
                "f:message": {},
                "f:reason": {},
                "f:status": {},
                "f:type": {}
              }
            }
          }
        },
        "subresource": "status"
      }
    ]
  },
  "spec": {},
  "status": {
    "phase": "Terminating",
    "conditions": [
      {
        "type": "NamespaceDeletionDiscoveryFailure",
        "status": "False",
        "lastTransitionTime": "2022-07-18T01:42:45Z",
        "reason": "ResourcesDiscovered",
        "message": "All resources successfully discovered"
      },
      {
        "type": "NamespaceDeletionGroupVersionParsingFailure",
        "status": "False",
        "lastTransitionTime": "2022-07-18T01:42:45Z",
        "reason": "ParsedGroupVersions",
        "message": "All legacy kube types successfully parsed"
      },
      {
        "type": "NamespaceDeletionContentFailure",
        "status": "True",
        "lastTransitionTime": "2022-07-18T01:43:22Z",
        "reason": "ContentDeletionFailed",
        "message": "Failed to delete all resource types, 1 remaining: unexpected items still remain in namespace: kubernetes-dashboard for gvr: /v1, Resource=pods"
      },
      {
        "type": "NamespaceContentRemaining",
        "status": "True",
        "lastTransitionTime": "2022-07-18T01:42:45Z",
        "reason": "SomeResourcesRemain",
        "message": "Some resources are remaining: pods. has 2 resource instances"
      },
      {
        "type": "NamespaceFinalizersRemaining",
        "status": "False",
        "lastTransitionTime": "2022-07-18T01:42:45Z",
        "reason": "ContentHasNoFinalizers",
        "message": "All content-preserving finalizers finished"
      }
    ]
  }
}

再次查看命名空间

[root@kubernetes-master-1 kubernetes]# kubectl get ns
NAME               STATUS   AGE
calico-apiserver   Active   2d18h
calico-system      Active   2d18h
default            Active   3d14h
kube-node-lease    Active   3d14h
kube-public        Active   3d14h
kube-system        Active   3d14h
tigera-operator    Active   2d18h

发现kubernetes-dashboard命名空间已经消失了。