(一)、Namespace概述
你可以认为namespaces是你kubernetes集群中的虚拟化集群。在一个Kubernetes集群中可以拥有多个命名空间，它们在逻辑上彼此隔离。 他们可以为您和您的团队提供组织，安全甚至性能方面的帮助！ 大多数的Kubernetes中的集群默认会有一个叫default的namespace。实际上，应该是3个：
default：你的service和应用pod默认被创建于此。 段落引用kube-system：kubernetes系统组件使用。 段落引用kube-public：公共资源使用。但实际上现在并不常用。
这个默认（default）的namespace并没什么特别，但你不能删除它。这很适合刚刚开始使用kubernetes和一些小的产品系统。但不建议应用于大型生产系统。因为，这种复杂系统中，团队会非常容易意外地或者无意识地重写或者中断其他服务service。相反，请创建多个命名空间来把你的服务service分割成更容易管理的块。
（二）、创建Namespace
不要害怕创建namespace。它不会降低服务的性能，反而大多情况下会提升你的工作效率。目前创建namespace时通过命令和yaml文件来进行创建的
2.1、通过命令创建命名空间
[root@k8s-master k8s]# kubectl create namespace test123
namespace/test123 created
[root@k8s-master k8s]# kubectl get namespace -owide
NAME STATUS AGE
default Active 55d
kube-node-lease Active 55d
kube-public Active 55d
kube-system Active 55d
test Active 21d
test123 Active 9s
2.2、通过yaml来进行创建
[root@k8s-master k8s]# kubectl apply -f namespace.yaml
namespace/test321 created
[root@k8s-master k8s]# cat namespace.yaml
apiVersion: v1
kind: Namespace
metadata:
name: test321
labels:
name: test
[root@k8s-master k8s]# kubectl get namespace -owide
NAME STATUS AGE
default Active 55d
kube-node-lease Active 55d
kube-public Active 55d
kube-system Active 55d
test Active 21d
test123 Active 7m6s
test321 Active 17s
（三）、在namespace中创建资源
3.1、创建一个pod没有指定命名空间的
[root@k8s-master namespace]# cat pod-ns.yml
apiVersion: v1
kind: Pod
metadata:
name: ns-pod
labels:
name: ns-pod
spec:
containers:
- name: ns-pod
image: nginx
[root@k8s-master namespace]# kubectl apply -f pod-ns.yml
pod/ns-pod created
[root@k8s-master namespace]# kubectl get pod/ns-pod
NAME READY STATUS RESTARTS AGE
ns-pod 1/1 Running 0 21s
3.2、创建一个pod指定命名空间的
[root@k8s-master namespace]# cat pod-ns2.yml
apiVersion: v1
kind: Pod
metadata:
name: ns-pod2
namespace: test
labels:
name: ns-pod2
spec:
containers:
- name: ns-pod2
image: nginx
[root@k8s-master namespace]# kubectl apply -f pod-ns2.yml
pod/ns-pod2 created
[root@k8s-master namespace]# kubectl get pod -ntest -owide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
ns-pod2 1/1 Running 0 94s 10.244.1.62 k8s-node01 <none> <none>
由于默认查询的是default命名空间，如果要查询test空间，则需要参数-ntest来查询test命名空间。 注意：命名空间名称满足正则表达式a-z0-9?,最大长度为63位
（四）、删除一个namespace
[root@k8s-master namespace]# kubectl delete namespaces test123
namespace "test123" deleted
注意： 删除一个namespace会自动删除所有属于该namespace的资源。 default和kube-system命名空间不可删除。
重点，删除namespace会出现Terminating处理步骤如下： 1、导出删除namespace的json文件
}[root@k8s-master ingress]#kubectl get ns
NAME STATUS AGE
default Active 69d
kube-node-lease Active 69d
kube-public Active 69d
kube-system Active 69d
test Active 34d
test321 Terminating 13d
[root@k8s-master ingress]# kubectl get ns/test321 -o json > test321.json
2、编辑该文件把spec.finalizers下的配置全部删除
"spec": {
"finalizers": [
"kubernetes"
]
}
3、运行kube-proxy
[root@k8s-master ingress]# kubectl proxy
Starting to serve on 127.0.0.1:8001
4、重启个窗口，通过api执行强制删除操作curl -k -H "Content-Type: application/json" -X PUT --data-binary @test321.json http://127.0.0.1:8001/api/v1/namespaces/test321/finalize
[root@k8s-master ingress]# curl -k -H "Content-Type: application/json" -X PUT --data-binary @test321.json http://127.0.0.1:8001/api/v1/namespaces/test321/finalize
{
"kind": "Namespace",
"apiVersion": "v1",
"metadata": {
"name": "test321",
"uid": "79aed65d-3cda-4eda-a240-0a33f26d5f9d",
"resourceVersion": "6929936",
"creationTimestamp": "2021-12-16T10:53:29Z",
"deletionTimestamp": "2021-12-17T10:14:42Z",
"labels": {
"kubernetes.io/metadata.name": "test321",
"name": "test"
},
"annotations": {
"kubectl.kubernetes.io/last-applied-configuration": "{\"apiVersion\":\"v1\",\"kind\":\"Namespace\",\"metadata\":{\"annotations\":{},\"labels\":{\"name\":\"test\"},\"name\":\"test321\"}}\n"
},
"managedFields": [
{
"manager": "kubectl-client-side-apply",
"operation": "Update",
"apiVersion": "v1",
"time": "2021-12-16T10:53:29Z",
"fieldsType": "FieldsV1",
"fieldsV1": {"f:metadata":{"f:annotations":{".":{},"f:kubectl.kubernetes.io/last-applied-configuration":{}},"f:labels":{".":{},"f:kubernetes.io/metadata.name":{},"f:name":{}}}}
},
{
"manager": "kube-controller-manager",
"operation": "Update",
"apiVersion": "v1",
"time": "2021-12-17T10:14:47Z",
"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": "True",
"lastTransitionTime": "2021-12-17T10:14:47Z",
"reason": "DiscoveryFailed",
"message": "Discovery failed for some groups, 2 failing: unable to retrieve the complete list of server APIs: auth.ilinux.io/v2beta1: the server is currently unable to handle the request, metrics.k8s.io/v1beta1: the server is currently unable to handle the request"
},
{
"type": "NamespaceDeletionGroupVersionParsingFailure",
"status": "False",
"lastTransitionTime": "2021-12-17T10:14:47Z",
"reason": "ParsedGroupVersions",
"message": "All legacy kube types successfully parsed"
},
{
"type": "NamespaceDeletionContentFailure",
"status": "False",
"lastTransitionTime": "2021-12-17T10:14:47Z",
"reason": "ContentDeleted",
"message": "All content successfully deleted, may be waiting on finalization"
},
{
"type": "NamespaceContentRemaining",
"status": "False",
"lastTransitionTime": "2021-12-17T10:14:47Z",
"reason": "ContentRemoved",
"message": "All content successfully removed"
},
{
"type": "NamespaceFinalizersRemaining",
"status": "False",
"lastTransitionTime": "2021-12-17T10:14:47Z",
"reason": "ContentHasNoFinalizers",
"message": "All content-preserving finalizers finished"
}
]
}
}
5、查看已经被删除 [root@k8s-master ingress]# kubectl get ns NAME STATUS AGE default Active 69d kube-node-lease Active 69d kube-public Active 69d kube-system Active 69d test Active 34d
