kubernetes自定义资源对象再极大程度提高了API Server的可扩展性,让企业能够根据业务需求通过CRD编写controller或者operator来实现生产中各种特殊场景。随着k8s的版本升级,CRD的功能也越来越完善,下面对其中几点进行说明。
以下验证kubernetes版本为1.13.2,docker版本:18.09.5
Validation(验证)
在项目中用自定义资源对象时,如果创建自定义资源时某些字段不符合要求,会导致监听该资源对象的controller或者operator出现异常,解析结构体报错,所以Validation这个功能非常实用,在创建时就进行校验,减少后面的排错和异常处理的麻烦。
可以通过 OpenAPI v3 schema验证自定义对象是否符合标准 。此外,以下限制适用于 schema:
- 字段
default
、nullable
、discriminator
、readOnly
、writeOnly
、xml
、deprecated
和$ref
不能设置。 - 该字段
uniqueItems
不能设置为 true。 - 该字段
additionalProperties
不能设置为 false。
可以使用 kube-apiserverCustomResourceValidation
上的功能门(feature gate)禁用此功能:
--feature-gates=CustomResourceValidation=false
从以下特性门参数说明地址,可以看到Validation功能在k8s 1.8版本就已经有了,但是CustomResourceValidation特性门是默认false,1.9Beta之后版本默认为true
https://kubernetes.io/docs/reference/command-line-tools-reference/feature-gates/
以下示例将大概对该功能进行应用和说明,在以下示例中,CustomResourceDefinition 对自定义对象应用以下验证:
-
spec.replicas
为必填项,类型为integer,值为大于等于0小于50的偶数(2的倍数); -
spec.repository
为必填项; -
spec.version
为必填项; -
spec.pause
为boolean类型; -
spec.updateStrategy
为object类型,该object中有type、pipeline、assignStrategies属性; -
spec.updateStrategy.type
为string类型,而且只能为"AssignReceive", "AutoReceive"两个枚举值; -
spec.updateStrategy.pipeline
为string类型,而且为正整数的字符串,符合正则表达式^([1-9][0-9]*){1,3}$
; -
spec.updateStrategy.assignStrategies
为array类型,其元素为object类型(包含slots和fromReplicas属性); -
spec.updateStrategy.assignStrategies.slots
为1-16384的正整数; -
spec.updateStrategy.assignStrategies.fromReplicas
为字符串,符合正则表达式^[a-z0-9,]{3,}$
,即至少匹配3位a-z或者0-9或者逗号的字符串; -
spec.pod
为array类型,其元素为object类型(包含configmap、monitorImage、initImage、middlewareImage字段); -
spec.pod.configmap
、spec.pod.monitorImage
、spec.pod.initImage
、spec.pod.middlewareImage
为string类型;且用required指定configmap、initImage、middlewareImage字段为必填项。
将以下内容保存到 redis-cluster-crd.yaml
:
apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
name: redisclusters.redis.middleware.hc.cn
spec:
group: redis.middleware.hc.cn
versions:
- name: v1alpha1
# Each version can be enabled/disabled by Served flag.
served: true
# One and only one version must be marked as the storage version.
storage: true
scope: Namespaced
names:
kind: RedisCluster
singular: rediscluster
listKind: RedisClusterList
plural: redisclusters
shortNames:
- rec
# 执行kubectl get all时会查到pod、service、该crd等属于all categories的资源对象
categories:
- all
validation:
# openAPIV3Schema 适用于验证自定义对象的 schema。
openAPIV3Schema:
properties:
spec:
required: ["replicas", "repository", "version"]
properties:
pause:
type: boolean
replicas:
type: integer
minimum: 0
maximum: 50
# 偶数
multipleOf: 2
updateStrategy:
type: object
properties:
type:
type: string
# 枚举
enum: ["AssignReceive", "AutoReceive"]
pipeline:
type: string
pattern: '^([1-9][0-9]*){1,3}$'
assignStrategies:
type: array
items:
type: object
properties:
slots:
type: integer
minimum: 1
maximum: 16384
fromReplicas:
type: string
# 至少匹配3位,a-z或者0-9或者,
pattern: '^[a-z0-9,]{3,}$'
pod:
type: array
items:
type: object
required: ["configmap", "middlewareImage", "initImage"]
properties:
configmap:
type: string
monitorImage:
type: string
initImage:
type: string
middlewareImage:
type: string
创建它:
kubectl create -f redis-cluster-crd.yaml
默认不加validation时,在创建自定义资源对象时,不会校验,有些字段没有了(如spec.replicas
)都可以正常被创建,为了减少排错的难度和operator、controller的麻烦的检验,所以在创建自定义资源定义时,就把validation加上。以上的检验应该覆盖到了常见的检验场景,其他场景可以自己摸索。具体还可以参考kubernetes源码,1.13.2版本kubernetes源码位于types.go第327行CustomResourceValidation结构体:
$GOPATH/src/k8s.io/kubernetes/staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/types.go
将以下YAML保存到redis-cluster-cr.yaml
:
apiVersion: redis.middleware.hc.cn/v1alpha1
kind: RedisCluster
metadata:
name: example000-redis-cluster
namespace: kube-system
spec:
# 代表redis集群的个数
replicas: 3
# 代表是否进入维修状态
pause: true
repository: library/redis
# 镜像版本,便于后续多版本特化支持
version: 3.2.6
#redis集群升级策略
updateStrategy:
# 升级类型为AutoReceive(自动分配,不用AssignStrategies), AssignReceive(指定值分配,需要用AssignStrategies)
type: AssignReceive1
pipeline: "100a"
assignStrategies:
-
slots: 0
fromReplicas: nodeId1
-
# 从nodeId3,nodeId4一共分配1000个卡槽
slots: 1000
# 多个nodeId用逗号分隔
fromReplicas: nodeId3,nodeId4
# redis 实例配置详情
pod:
# 配置文件模板名
- configmap: example000-redis-cluster-config
# 监控镜像
monitorImage: redis-exporter:v1
# 初始化镜像
#initImage: redis-init:v1
# 中间件容器镜像
middlewareImage: redis-trib:3.2.6
并创建它:
kubectl create -f redis-cluster-cr.yaml
会发现报以下错误:
# kubectl apply -f redis-cluster-cr.yaml
The RedisCluster "example000-redis-cluster" is invalid: []: Invalid value: map[string]interface {}{"apiVersion":"redis.middleware.hc.cn/v1alpha1", "kind":"RedisCluster", "metadata":map[string]interface {}{"namespace":"kube-system", "uid":"b0946031-766b-11e9-b457-000c295db389", "resourceVersion":"44231", "generation":19, "creationTimestamp":"2019-05-14T17:14:10Z", "annotations":map[string]interface {}{"kubectl.kubernetes.io/last-applied-configuration":"{\"apiVersion\":\"redis.middleware.hc.cn/v1alpha1\",\"kind\":\"RedisCluster\",\"metadata\":{\"annotations\":{},\"name\":\"example000-redis-cluster\",\"namespace\":\"kube-system\"},\"spec\":{\"pause\":true,\"pod\":[{\"configmap\":\"example000-redis-cluster-config\",\"middlewareImage\":\"redis-trib:3.2.6\",\"monitorImage\":\"redis-exporter:v1\"}],\"replicas\":3,\"repository\":\"library/redis\",\"updateStrategy\":{\"assignStrategies\":[{\"fromReplicas\":\"nodeId1\",\"slots\":0},{\"fromReplicas\":\"nodeId3,nodeId4\",\"slots\":1000}],\"pipeline\":\"100a\",\"type\":\"AssignReceive1\"},\"version\":\"3.2.6\"}}\n"}, "name":"example000-redis-cluster"}, "spec":map[string]interface {}{"version":"3.2.6", "pause":true, "pod":[]interface {}{map[string]interface {}{"middlewareImage":"redis-trib:3.2.6", "monitorImage":"redis-exporter:v1", "configmap":"example000-redis-cluster-config"}}, "replicas":3, "repository":"library/redis", "updateStrategy":map[string]interface {}{"assignStrategies":[]interface {}{map[string]interface {}{"fromReplicas":"nodeId1", "slots":0}, map[string]interface {}{"fromReplicas":"nodeId3,nodeId4", "slots":1000}}, "pipeline":"100a", "type":"AssignReceive1"}}}: validation failure list:
spec.updateStrategy.assignStrategies.fromReplicas in body should match '^[a-z0-9,]{3,}$'
spec.updateStrategy.assignStrategies.slots in body should be greater than or equal to 1
spec.updateStrategy.pipeline in body should match '^([1-9][0-9]*){1,3}$'
spec.updateStrategy.type in body should be one of [AssignReceive AutoReceive]
spec.pod.initImage in body is required
spec.replicas in body should be a multiple of 2
如果所有字段都符合校验逻辑,才可以创建对象。
将以下 YAML 保存到 redis-cluster-cr.yaml
:
apiVersion: redis.middleware.hc.cn/v1alpha1
kind: RedisCluster
metadata:
name: example000-redis-cluster
namespace: kube-system
spec:
# 代表redis集群的个数
replicas: 6
# 代表是否进入维修状态
pause: true
repository: library/redis
# 镜像版本,便于后续多版本特化支持
version: 3.2.6
#redis集群升级策略
updateStrategy:
# 升级类型为AutoReceive(自动分配,不用AssignStrategies), AssignReceive(指定值分配,需要用AssignStrategies)
type: AssignReceive
pipeline: "100"
assignStrategies:
-
slots: 1
fromReplicas: all
-
# 从nodeId3,nodeId4一共分配1000个卡槽
slots: 1000
# 多个nodeId用逗号分隔
fromReplicas: node1,node2
# redis 实例配置详情
pod:
# 配置文件模板名
- configmap: example000-redis-cluster-config
# 监控镜像
monitorImage: redis-exporter:v1
# 初始化镜像
initImage: redis-init:v1
# 中间件容器镜像
middlewareImage: redis-trib:3.2.6
并创建它,发现才可以创建:
# kubectl apply -f redis-cluster-cr.yaml
rediscluster.redis.middleware.hc.cn/example000-redis-cluster configured
Category(分类)
类别是自定义资源所属的分组资源的列表(例如 all
)。您可以使用 kubectl get <category-name>
列出属于该类别的资源。此功能可用于 v1.10 及以上k8s版本自定义资源。
以下示例添加 all
CustomResourceDefinition 中的类别列表,并说明如何使用 kubectl get all
输出自定义资源 。
将以下 内容保存到 redis-cluster-crd.yaml
中执行kubectl apply -f redis-cluster-crd.yaml
:
apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
name: redisclusters.redis.middleware.hc.cn
spec:
group: redis.middleware.hc.cn
versions:
- name: v1alpha1
# Each version can be enabled/disabled by Served flag.
served: true
# One and only one version must be marked as the storage version.
storage: true
scope: Namespaced
names:
kind: RedisCluster
singular: rediscluster
listKind: RedisClusterList
plural: redisclusters
shortNames:
- rec
# 执行kubectl get all时会查到pod、service、该crd等属于all categories的资源对象
categories:
- all
将以下内容保存到redis-cluster-cr.yaml
中执行kubectl apply -f redis-cluster-cr.yaml
:
apiVersion: redis.middleware.hc.cn/v1alpha1
kind: RedisCluster
metadata:
name: example000-redis-cluster
namespace: kube-system
spec:
# 代表redis集群的个数
replicas: 6
# 代表是否进入维修状态
pause: true
repository: library/redis
# 镜像版本,便于后续多版本特化支持
version: 3.2.6
#redis集群升级策略
updateStrategy:
# 升级类型为AutoReceive(自动分配,不用AssignStrategies), AssignReceive(指定值分配,需要用AssignStrategies)
type: AssignReceive
pipeline: "100"
assignStrategies:
-
slots: 2000
fromReplicas: nodeId1
-
# 从nodeId3,nodeId4一共分配1000个卡槽
slots: 1000
# 多个nodeId用逗号分隔
fromReplicas: nodeId3,nodeId4
# redis 实例配置详情
pod:
# 配置文件模板名
- configmap: example000-redis-cluster-config
# 监控镜像
monitorImage: redis-exporter:v1
# 初始化镜像
initImage: redis-init:v1
# 中间件容器镜像
middlewareImage: redis-trib:3.2.6
执行kubectl get all时会查到pod、service、该crd等属于all categories的资源对象。(这个可能得等几分钟才能生效)
子资源
status子资源
启用状态子资源后,将公开自定义资源的子资源 /status
。
- 状态和规范节分别由自定义资源内的
.status
和.spec
JSONPath 表示。 -
PUT /status
对子资源的请求采用自定义资源对象,并忽略除状态节之外的任何更改。 -
PUT /status
对子资源的请求仅验证自定义资源的状态节。 -
PUT/ POST/ PATCH
请求自定义资源忽略更改状态节。 - 对 spec 节的任何更改都会增加
.metadata.generation
的值。
在code-generator生成代码时会生成,如下方法:
// RedisClusterInterface has methods to work with RedisCluster resources.
type RedisClusterInterface interface {
Create(*v1alpha1.RedisCluster) (*v1alpha1.RedisCluster, error)
Update(*v1alpha1.RedisCluster) (*v1alpha1.RedisCluster, error)
UpdateStatus(*v1alpha1.RedisCluster) (*v1alpha1.RedisCluster, error)
......
}
scale子资源
启用 scale 子资源后,将公开自定义资源的子资源 /scale
。该 autoscaling/v1.Scale 对象作为有效负载发送 /scale。
要启用 scale 子资源,CustomResourceDefinition 中需要定义以下值。
SpecReplicasPath 在与之对应的自定义资源中定义 JSONPath Scale.Spec.Replicas。这是一个必需的值。.spec 只允许使用带点符号的 JSONPaths 。如果 SpecReplicasPath 自定义资源中没有值,则 /scale 子资源将在GET上返回错误。
StatusReplicasPath 在与之对应的自定义资源中定义 JSONPath Scale.Status.Replicas。这是一个必需的值。.stutus 只允许使用带点符号的 JSONPaths 。如果 StatusReplicasPath 自定义资源中没有值,则子资源 /scale 中的状态副本值将默认为 0。
LabelSelectorPath在与之对应的自定义资源中定义 JSONPath Scale.Status.Selector。这是一个可选值。必须将其设置为与 HPA 一起使用。.status 只允许使用带点符号的 JSONPaths 。如果 LabelSelectorPath 自定义资源中没有值,则子资源 /scale 中的状态选择器值将默认为空字符串。
在以下示例中,启用了status 和 scale 子资源。
将以下内容保存到redis-cluster-crd.yaml
并创建 kubectl apply -f redis-cluster-crd.yaml
:
apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
name: redisclusters.redis.middleware.hc.cn
spec:
group: redis.middleware.hc.cn
versions:
- name: v1alpha1
# Each version can be enabled/disabled by Served flag.
served: true
# One and only one version must be marked as the storage version.
storage: true
scope: Namespaced
names:
kind: RedisCluster
singular: rediscluster
listKind: RedisClusterList
plural: redisclusters
shortNames:
- rec
# 执行kubectl get all时会查到pod、service、该crd等属于all categories的资源对象
categories:
- all
subresources:
# status enables the status subresource.
status: {}
scale:
# specReplicasPath defines the JSONPath inside of a custom resource that corresponds to Scale.Spec.Replicas.
specReplicasPath: .spec.replicas
# statusReplicasPath defines the JSONPath inside of a custom resource that corresponds to Scale.Status.Replicas.
statusReplicasPath: .status.replicas
# labelSelectorPath defines the JSONPath inside of a custom resource that corresponds to Scale.Status.Selector.
labelSelectorPath: .status.labelSelector
创建 CustomResourceDefinition 对象后,您可以创建自定义对象。
如果您将以下 YAML 保存到 redis-cluster-cr.yaml
:
apiVersion: redis.middleware.hc.cn/v1alpha1
kind: RedisCluster
metadata:
name: example000-redis-cluster
namespace: kube-system
spec:
# 代表redis集群的个数
replicas: 6
# 代表是否进入维修状态
pause: true
repository: library/redis
# 镜像版本,便于后续多版本特化支持
version: 3.2.6
#redis集群升级策略
updateStrategy:
# 升级类型为AutoReceive(自动分配,不用AssignStrategies), AssignReceive(指定值分配,需要用AssignStrategies)
type: AssignReceive
pipeline: "100"
assignStrategies:
-
slots: 2000
fromReplicas: nodeId1
-
# 从nodeId3,nodeId4一共分配1000个卡槽
slots: 1000
# 多个nodeId用逗号分隔
fromReplicas: nodeId3,nodeId4
# redis 实例配置详情
pod:
# 配置文件模板名
- configmap: example000-redis-cluster-config
# 监控镜像
monitorImage: redis-exporter:v1
# 初始化镜像
initImage: redis-init:v1
# 中间件容器镜像
middlewareImage: redis-trib:3.2.6
并创建它:
kubectl create -f redis-cluster-cr.yaml
然后在以下位置创建新的命名空间 RESTful API 端点:
/apis/redis.middleware.hc.cn/v1alpha1/namespaces/kube-system/redisclusters/example000-redis-cluster/status
和
/apis/redis.middleware.hc.cn/v1alpha1/namespaces/kube-system/redisclusters/example000-redis-cluster/scale
可以使用该 kubectl scale
命令缩放自定义资源。例如,以上创建的自定义资源的的 .spec.replicas
设置为 10:
# kubectl get rec --all-namespaces
NAMESPACE NAME DESIRED PAUSE AGE
kube-system example000-redis-cluster 6 true 10h
# kubectl scale --replicas=10 rec/example000-redis-cluster -nkube-system
rediscluster.redis.middleware.hc.cn/example000-redis-cluster scaled
# kubectl get rec --all-namespaces
NAMESPACE NAME DESIRED PAUSE AGE
kube-system example000-redis-cluster 10 true 10h
# kubectl get rec example000-redis-cluster -n kube-system -o jsonpath='{.spec.replicas}'
10
打印其他列
从 Kubernetes 1.11 开始,kubectl 使用服务器端打印。服务器决定 kubectl get
命令显示哪些列。您可以使用 CustomResourceDefinition 自定义这些列。下面的示例将输出 Spec
、Replicas
和 Age
列。
-
将 CustomResourceDefinition保存到
redis-cluster-crd.yaml
。apiVersion: apiextensions.k8s.io/v1beta1 kind: CustomResourceDefinition metadata: name: redisclusters.redis.middleware.hc.cn spec: group: redis.middleware.hc.cn versions: - name: v1alpha1 # Each version can be enabled/disabled by Served flag. served: true # One and only one version must be marked as the storage version. storage: true scope: Namespaced names: kind: RedisCluster singular: rediscluster listKind: RedisClusterList plural: redisclusters shortNames: - rec # 执行kubectl get all时会查到pod、service、该crd等属于all categories的资源对象 categories: - all additionalPrinterColumns: - name: DESIRED type: integer description: The number of statefulset managed by the this redisCluster JSONPath: .spec.replicas # boolean,date,integer,number,string - name: PAUSE type: boolean description: Whether this redisCluster's grandson (pod) will not be managed by statefulset JSONPath: .spec.pause
-
创建 CustomResourceDefinition:
kubectl create -f redis-cluster-crd.yaml
使用上面创建的
redis-cluster-cr.yaml
实例。-
调用服务器端打印:
kubectl get rec --all-namespaces
请注意
NAME
、NAMESPACE
,DESIRED
、PAUSE
和AGE
在输出列,并且都被转成了大写字母:[root@master-192 redis-container]# kubectl get rec --all-namespaces NAMESPACE NAME DESIRED PAUSE AGE kube-system example000-redis-cluster 6 true 10h
NAME
和NAMESPACE
列是隐含的,不需要在 CustomResourceDefinition 中定义。
operator中应用该特性
在golang编写的operator代码中创建该结构体:
//创建CRD
func CreateRedisClusterCRD(extensionCRClient *extensionsclient.Clientset) error {
//add CustomResourceValidation due to guarantee redis operator work normally
labelSelectorPath := ".status.labelSelector"
replicasMinimum := float64(0)
replicasMaximum := float64(50)
replicasMultipleOf := float64(2)
slotsMinimum := float64(1)
slotsMaximum := float64(16384)
assignStr := "AssignReceive"
autoStr := "AutoReceive"
assignJson, _ := json.Marshal(assignStr)
autoJson, _ := json.Marshal(autoStr)
crd := &v1beta1.CustomResourceDefinition{
ObjectMeta: metav1.ObjectMeta{
Name: "redisclusters." + v1alpha1.SchemeGroupVersion.Group,
},
Spec: v1beta1.CustomResourceDefinitionSpec{
Group: v1alpha1.SchemeGroupVersion.Group,
Versions: []v1beta1.CustomResourceDefinitionVersion {
{
// Served is a flag enabling/disabling this version from being served via REST APIs
Served: true,
Name: v1alpha1.SchemeGroupVersion.Version,
// Storage flags the version as storage version. There must be exactly one flagged as storage version
Storage: true,
},
},
Scope: v1beta1.NamespaceScoped,
Names: v1beta1.CustomResourceDefinitionNames{
Kind: "RedisCluster",
ListKind: "RedisClusterList",
Plural: "redisclusters",
Singular: "rediscluster",
ShortNames: []string{"rec"},
Categories: []string{"all"},
},
Subresources: &v1beta1.CustomResourceSubresources {
Status: &v1beta1.CustomResourceSubresourceStatus {},
Scale: &v1beta1.CustomResourceSubresourceScale {
SpecReplicasPath: ".spec.replicas",
StatusReplicasPath: ".status.replicas",
LabelSelectorPath: &labelSelectorPath,
},
},
AdditionalPrinterColumns: []v1beta1.CustomResourceColumnDefinition{
{
Name: "DESIRED",
Type: "integer",
Description: "The number of statefulset managed by the this redisCluster",
JSONPath: ".spec.replicas",
},
{
Name: "PAUSE",
Type: "boolean",
Description: "Whether this redisCluster's grandson (pod) will not be managed by statefulset",
JSONPath: ".spec.pause",
},
{
Name: "AGE",
Type: "date",
JSONPath: ".metadata.creationTimestamp",
},
},
Validation: &v1beta1.CustomResourceValidation {
OpenAPIV3Schema: &v1beta1.JSONSchemaProps {
Properties: map[string]v1beta1.JSONSchemaProps {
"spec": {
Required: []string{"replicas", "repository", "version"},
Properties: map[string]v1beta1.JSONSchemaProps{
"pause": {
Type: "boolean",
},
"replicas": {
Type: "integer",
Minimum: &replicasMinimum,
Maximum: &replicasMaximum,
MultipleOf: &replicasMultipleOf,
},
"updateStrategy": {
Type: "object",
Properties: map[string]v1beta1.JSONSchemaProps{
"type": {
Type: "string",
Enum: []v1beta1.JSON {
{
//这里必须是JSON格式的字符串
Raw: assignJson,
},
{
Raw: autoJson,
},
},
},
"pipeline": {
Type: "string",
Pattern: `^([1-9][0-9]*){1,3}$`,
},
"assignStrategies": {
Type: "array",
Items: &v1beta1.JSONSchemaPropsOrArray{
Schema: &v1beta1.JSONSchemaProps{
Type: "object",
Properties: map[string]v1beta1.JSONSchemaProps{
"slots": {
Type: "integer",
Minimum: &slotsMinimum,
Maximum: &slotsMaximum,
},
"fromReplicas": {
Type: "string",
Pattern: `^[a-z0-9,]{3,}$`,
},
},
},
},
},
},
},
},
},
"pod": {
Type: "array",
Items: &v1beta1.JSONSchemaPropsOrArray {
Schema: &v1beta1.JSONSchemaProps {
Type: "object",
Required: []string{"replicas", "repository", "version"},
Properties: map[string]v1beta1.JSONSchemaProps{
"configmap": {
Type: "string",
},
"monitorImage": {
Type: "string",
},
"initImage": {
Type: "string",
},
"middlewareImage": {
Type: "string",
},
},
},
},
},
},
},
},
},
}
_, err := extensionCRClient.ApiextensionsV1beta1().CustomResourceDefinitions().Create(crd)
return err
}
参考
官方Extend the Kubernetes API with CustomResourceDefinitions:
https://kubernetes.io/docs/tasks/access-kubernetes-api/custom-resources/custom-resource-definitions/
feature-gates参数说明:
https://kubernetes.io/docs/reference/command-line-tools-reference/feature-gates/
CustomResourceDefinition中文文档:
https://kubernetes.feisky.xyz/cha-jian-kuo-zhan/api/customresourcedefinition
swagger和openAPI: 数据类型:
https://www.breakyizhan.com/swagger/2969.html
正则表达式:
https://www.cnblogs.com/afarmer/archive/2011/08/29/2158860.html
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