记一次删除k8s namespace无法删除的问题

　　在用longhorn工具做k8s存储卷动态预配的时候，需要修改longhorn.yaml的一个默认参数，修改完成需要重新加载longhorn.yaml，结果重新加载出错了，修改的参数没有生效，于是执行kubectl delete -f longhorn.yaml想将部署的资源全部删除重新启动；但是发现创建的namespace无法删除，状态一直是Terminating；

[root@k8smaster longhorn]# kubectl get ns
NAME              STATUS        AGE
default           Active        49d
dev               Active        29d
kube-node-lease   Active        49d
kube-public       Active        49d
kube-system       Active        49d
longhorn-system   Terminating   11h
stage             Active        29d
[root@k8smaster longhorn]# kubectl delete ns longhorn-system
Error from server (Conflict): Operation cannot be fulfilled on namespaces "longhorn-system": The system is ensuring all content is removed from this namespace.  Upon completion, this namespace will automatically be purged by the system.
从报错来看是因为在该名称空间中还有没有删除的内容，但是查找了该名称空间，该名称空间中已经没有运行的pod了；

解决方式：通过api来删除

先查找到该namespace的api接口地址
[root@k8smaster longhorn]# kubectl get ns/longhorn-system -o yaml
apiVersion: v1
kind: Namespace
metadata:
  annotations:
    kubectl.kubernetes.io/last-applied-configuration: |
      {"apiVersion":"v1","kind":"Namespace","metadata":{"annotations":{},"name":"longhorn-system"}}
  creationTimestamp: "2021-06-29T15:43:23Z"
  deletionTimestamp: "2021-06-30T02:48:32Z"
  name: longhorn-system
  resourceVersion: "6197365"
  selfLink: /api/v1/namespaces/longhorn-system
  uid: bcc59118-d8f0-11eb-b1e9-000c29087c24
spec:
  finalizers:
  - kubernetes
status:
  phase: Terminating

导出该namespace json格式的详细信息
[root@k8smaster longhorn]# kubectl get ns longhorn-system -o json > longhorn-system.json
[root@k8smaster longhorn]# cat longhorn-system.json
{
    "apiVersion": "v1",
    "kind": "Namespace",
    "metadata": {
        "annotations": {
            "kubectl.kubernetes.io/last-applied-configuration": "{\"apiVersion\":\"v1\",\"kind\":\"Namespace\",\"metadata\":{\"annotations\":{},\"name\":\"longhorn-system\"}}\n"
        },
        "creationTimestamp": "2021-06-29T15:43:23Z",
        "deletionTimestamp": "2021-06-30T02:48:32Z",
        "name": "longhorn-system",
        "resourceVersion": "6197365",
        "selfLink": "/api/v1/namespaces/longhorn-system",
        "uid": "bcc59118-d8f0-11eb-b1e9-000c29087c24"
    },
    "spec": {
        "finalizers": [
            "kubernetes"
        ]
    },
    "status": {
        "phase": "Terminating"
    }
}
删除finalizers的认证方式;
删除后的json文件;
[root@k8smaster longhorn]# cat longhorn-system.json
{
    "apiVersion": "v1",
    "kind": "Namespace",
    "metadata": {
        "annotations": {
            "kubectl.kubernetes.io/last-applied-configuration": "{\"apiVersion\":\"v1\",\"kind\":\"Namespace\",\"metadata\":{\"annotations\":{},\"name\":\"longhorn-system\"}}\n"
        },
        "creationTimestamp": "2021-06-29T15:43:23Z",
        "deletionTimestamp": "2021-06-30T02:48:32Z",
        "name": "longhorn-system",
        "resourceVersion": "6197365",
        "selfLink": "/api/v1/namespaces/longhorn-system",
        "uid": "bcc59118-d8f0-11eb-b1e9-000c29087c24"
    },
    "spec": {
        "finalizers": [
        ]
    },
    "status": {
        "phase": "Terminating"
    }
}

调用接口删除该namespace
1、因为k8s接口默认使用https访问的，所以需要临时开一个HTTP代理端口
[root@k8smaster ~]# kubectl proxy
Starting to serve on 127.0.0.1:8001
2、新开一个终端，执行调用接口命令，注意接口最后加上finalize
[root@k8smaster longhorn]# curl -k -H "Content-Type: application/json" -X PUT --data-binary @longhorn-system.json http://127.0.0.1:8001/api/v1/namespaces/longhorn-system/finalize
{
  "kind": "Namespace",
  "apiVersion": "v1",
  "metadata": {
    "name": "longhorn-system",
    "selfLink": "/api/v1/namespaces/longhorn-system/finalize",
    "uid": "bcc59118-d8f0-11eb-b1e9-000c29087c24",
    "resourceVersion": "6202444",
    "creationTimestamp": "2021-06-29T15:43:23Z",
    "deletionTimestamp": "2021-06-30T02:48:32Z",
    "annotations": {
      "kubectl.kubernetes.io/last-applied-configuration": "{\"apiVersion\":\"v1\",\"kind\":\"Namespace\",\"metadata\":{\"annotations\":{},\"name\":\"longhorn-system\"}}\n"
    }
  },
  "spec": {

  },
  "status": {
    "phase": "Terminating"
  }
}
3、查看k8s的ns，发现longhorn-system被删除了
[root@k8smaster longhorn]#kubectl get ns
NAME              STATUS   AGE
default           Active   49d
dev               Active   29d
kube-node-lease   Active   49d
kube-public       Active   49d
kube-system       Active   49d
stage             Active   29d