文章目录
- 1、Ingres简介
- 2、Ingres网络模型分析
- 3、安装Ingress
- 4、使用
- 4.1、搭建测试环境
- 4.2、域名访问
- 4.3、路径重写（高级用法）
- 4.4、流量限制（高级用法）
- 5、总结
1、Ingres简介
Ingress翻译过来是“入口”的意思，也就是说：K8S希望Ingress能成为整个k8s集群的流量入口；Ingress网络是一组规则，充当Kubernetes集群的入口点。
- Ingress：Service的统一网关入口
- Service：Pod的统一网关入口
所有流量首先进入Ingress，由Ingress转交给Service，最终由Service负载均衡后交到各个Pod应用。
Ingress其实就是nginx封装的一个API对象。，通常通过HTTP管理集群中服务的外部访问，是暴露服务的最有效方式。
2、Ingres网络模型分析
举例说明：
-
某个产品有三个服务：分别为订单服务+用户服务+产品服务
-
部署三台机子
- 订单服务：部署了两个Pod应用分别在两台机子
- 用户服务：部署了三个Pod应用分别在三台机子
- 产品服务：部署了三个Pod应用分别在三台机子
首先形成了两层网络服务，如下图：
- Service层网络
- Pod层网络
通过增加Ingress网络层，统一Service网络层的网关。
最终形成三层网络的架构设计。
- Ingres网络层（最外层）
- Service网络层
- Pod网络层
3、安装Ingress
wget https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v0.47.0/deploy/static/provider/baremetal/deploy.yaml#修改镜像
vi deploy.yaml
#将image的值改为如下值：
registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/ingress-nginx-controller:v0.46.0# 检查安装的结果
kubectl get pod,svc -n ingress-nginx# 最后别忘记把svc暴露的端口要放行
注意两点：
- 下载yml文件
- 修改阿里云的镜像地址
使用yml进行安装Ingress
在集群中安装完Ingress后，会生成service，暴露两个端口供外部访问。
http /https
以NodePort方式暴露外部访问的端口
4、使用
官网地址：https://kubernetes.github.io/ingress-nginx/
4.1、搭建测试环境
测试环境：应用如下yaml，准备好测试环境
apiVersion: apps/v1
kind: Deployment
metadata:name: hello-server
spec:replicas: 2selector:matchLabels:app: hello-servertemplate:metadata:labels:app: hello-serverspec:containers:- name: hello-serverimage: registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/hello-serverports:- containerPort: 9000
---
apiVersion: apps/v1
kind: Deployment
metadata:labels:app: nginx-demoname: nginx-demo
spec:replicas: 2selector:matchLabels:app: nginx-demotemplate:metadata:labels:app: nginx-demospec:containers:- image: nginxname: nginx
---
apiVersion: v1
kind: Service
metadata:labels:app: nginx-demoname: nginx-demo
spec:selector:app: nginx-demoports:- port: 8000protocol: TCPtargetPort: 80
---
apiVersion: v1
kind: Service
metadata:labels:app: hello-servername: hello-server
spec:selector:app: hello-serverports:- port: 8000protocol: TCPtargetPort: 9000
上述yml说明：
以Deployment方式部署了两个应用，分别为：
- hello-server： 镜像名hello-server：两个副本，暴露端口8000，目标端口9000
- nginx-demo：镜像名nginx：两个副本，暴露端口8000，目标端口80
同时也生成对应的两个service，分别为：nginx-demo和hello-serve
4.2、域名访问
通过下面的yml文件，创建一个ingress资源。
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:name: ingress-host-bar
spec:ingressClassName: nginxrules:- host: "hello.atguigu.com"http:paths:- pathType: Prefixpath: "/"backend:service:name: hello-serverport:number: 8000- host: "demo.atguigu.com"http:paths:- pathType: Prefixpath: "/nginx" # 把请求会转给下面的服务，下面的服务一定要能处理这个路径，不能处理就是404backend:service:name: nginx-demo ## java，比如使用路径重写，去掉前缀nginxport:number: 8000
访问规则描述：
- 访问域名hello.atguigu.com，会转到service：hello-server应用
- 访问域名demo.atguigu.com/nginx，会转到service：nginx-demo应用
问题： path: “/nginx” 与 path: “/” 为什么会有不同的效果？
回答：上述yaml中加了路径/nginx，如果访问域名中也加了/nginx路径，说明访问域名路径一直，Ingress会处理这个路径请求，然后转发到service层nginx-demo，从而service层nginx-demo将请求流量负载均衡到各个pod；如果访问域名路径不一致，Ingress就不能处理这个路径，也就起不到转发路由的作用，因为ingress本身就是nginx，所以页面也会显示nginx的404，但不一样的是：此时nginx不带版本号。
4.3、路径重写（高级用法）
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:annotations:nginx.ingress.kubernetes.io/rewrite-target: /$2name: ingress-host-bar
spec:ingressClassName: nginxrules:- host: "hello.atguigu.com"http:paths:- pathType: Prefixpath: "/"backend:service:name: hello-serverport:number: 8000- host: "demo.atguigu.com"http:paths:- pathType: Prefixpath: "/nginx(/|$)(.*)" # 把请求会转给下面的服务，下面的服务一定要能处理这个路径，不能处理就是404backend:service:name: nginx-demo ## java，比如使用路径重写，去掉前缀nginxport:number: 8000
4.4、流量限制（高级用法）
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:name: ingress-limit-rateannotations:nginx.ingress.kubernetes.io/limit-rps: "1"
spec:ingressClassName: nginxrules:- host: "haha.atguigu.com"http:paths:- pathType: Exactpath: "/"backend:service:name: nginx-demoport:number: 8000
说明：
- exact：精确匹配路径类型
- 配置rps每秒请求接受的请求数为1
如果超过配置中的限制，访问就会报503的错误，起到限流的作用。
5、总结
最终，k8s集群网络模型包括三层网络模型构成，即：
- Ingress层
- Service层
- Pod层
另外在实际工作中，也可以在Ingress层外部设置一个LoadBalance层，请求流量首先经过外部的LB负载均衡到各个机子，然后在Ingress、Service和Pod层之间传递。
附录：ingress-nginx安装的yml文件
apiVersion: v1
kind: Namespace
metadata:name: ingress-nginxlabels:app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginx---
# Source: ingress-nginx/templates/controller-serviceaccount.yaml
apiVersion: v1
kind: ServiceAccount
metadata:labels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: controllername: ingress-nginxnamespace: ingress-nginx
automountServiceAccountToken: true
---
# Source: ingress-nginx/templates/controller-configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:labels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: controllername: ingress-nginx-controllernamespace: ingress-nginx
data:
---
# Source: ingress-nginx/templates/clusterrole.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:labels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmname: ingress-nginx
rules:- apiGroups:- ''resources:- configmaps- endpoints- nodes- pods- secretsverbs:- list- watch- apiGroups:- ''resources:- nodesverbs:- get- apiGroups:- ''resources:- servicesverbs:- get- list- watch- apiGroups:- extensions- networking.k8s.io # k8s 1.14+resources:- ingressesverbs:- get- list- watch- apiGroups:- ''resources:- eventsverbs:- create- patch- apiGroups:- extensions- networking.k8s.io # k8s 1.14+resources:- ingresses/statusverbs:- update- apiGroups:- networking.k8s.io # k8s 1.14+resources:- ingressclassesverbs:- get- list- watch
---
# Source: ingress-nginx/templates/clusterrolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:labels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmname: ingress-nginx
roleRef:apiGroup: rbac.authorization.k8s.iokind: ClusterRolename: ingress-nginx
subjects:- kind: ServiceAccountname: ingress-nginxnamespace: ingress-nginx
---
# Source: ingress-nginx/templates/controller-role.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:labels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: controllername: ingress-nginxnamespace: ingress-nginx
rules:- apiGroups:- ''resources:- namespacesverbs:- get- apiGroups:- ''resources:- configmaps- pods- secrets- endpointsverbs:- get- list- watch- apiGroups:- ''resources:- servicesverbs:- get- list- watch- apiGroups:- extensions- networking.k8s.io # k8s 1.14+resources:- ingressesverbs:- get- list- watch- apiGroups:- extensions- networking.k8s.io # k8s 1.14+resources:- ingresses/statusverbs:- update- apiGroups:- networking.k8s.io # k8s 1.14+resources:- ingressclassesverbs:- get- list- watch- apiGroups:- ''resources:- configmapsresourceNames:- ingress-controller-leader-nginxverbs:- get- update- apiGroups:- ''resources:- configmapsverbs:- create- apiGroups:- ''resources:- eventsverbs:- create- patch
---
# Source: ingress-nginx/templates/controller-rolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:labels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: controllername: ingress-nginxnamespace: ingress-nginx
roleRef:apiGroup: rbac.authorization.k8s.iokind: Rolename: ingress-nginx
subjects:- kind: ServiceAccountname: ingress-nginxnamespace: ingress-nginx
---
# Source: ingress-nginx/templates/controller-service-webhook.yaml
apiVersion: v1
kind: Service
metadata:labels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: controllername: ingress-nginx-controller-admissionnamespace: ingress-nginx
spec:type: ClusterIPports:- name: https-webhookport: 443targetPort: webhookselector:app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/component: controller
---
# Source: ingress-nginx/templates/controller-service.yaml
apiVersion: v1
kind: Service
metadata:annotations:labels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: controllername: ingress-nginx-controllernamespace: ingress-nginx
spec:type: NodePortports:- name: httpport: 80protocol: TCPtargetPort: http- name: httpsport: 443protocol: TCPtargetPort: httpsselector:app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/component: controller
---
# Source: ingress-nginx/templates/controller-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:labels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: controllername: ingress-nginx-controllernamespace: ingress-nginx
spec:selector:matchLabels:app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/component: controllerrevisionHistoryLimit: 10minReadySeconds: 0template:metadata:labels:app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/component: controllerspec:dnsPolicy: ClusterFirstcontainers:- name: controllerimage: registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/ingress-nginx-controller:v0.46.0imagePullPolicy: IfNotPresentlifecycle:preStop:exec:command:- /wait-shutdownargs:- /nginx-ingress-controller- --election-id=ingress-controller-leader- --ingress-class=nginx- --configmap=$(POD_NAMESPACE)/ingress-nginx-controller- --validating-webhook=:8443- --validating-webhook-certificate=/usr/local/certificates/cert- --validating-webhook-key=/usr/local/certificates/keysecurityContext:capabilities:drop:- ALLadd:- NET_BIND_SERVICErunAsUser: 101allowPrivilegeEscalation: trueenv:- name: POD_NAMEvalueFrom:fieldRef:fieldPath: metadata.name- name: POD_NAMESPACEvalueFrom:fieldRef:fieldPath: metadata.namespace- name: LD_PRELOADvalue: /usr/local/lib/libmimalloc.solivenessProbe:failureThreshold: 5httpGet:path: /healthzport: 10254scheme: HTTPinitialDelaySeconds: 10periodSeconds: 10successThreshold: 1timeoutSeconds: 1readinessProbe:failureThreshold: 3httpGet:path: /healthzport: 10254scheme: HTTPinitialDelaySeconds: 10periodSeconds: 10successThreshold: 1timeoutSeconds: 1ports:- name: httpcontainerPort: 80protocol: TCP- name: httpscontainerPort: 443protocol: TCP- name: webhookcontainerPort: 8443protocol: TCPvolumeMounts:- name: webhook-certmountPath: /usr/local/certificates/readOnly: trueresources:requests:cpu: 100mmemory: 90MinodeSelector:kubernetes.io/os: linuxserviceAccountName: ingress-nginxterminationGracePeriodSeconds: 300volumes:- name: webhook-certsecret:secretName: ingress-nginx-admission
---
# Source: ingress-nginx/templates/admission-webhooks/validating-webhook.yaml
# before changing this value, check the required kubernetes version
# https://kubernetes.io/docs/reference/access-authn-authz/extensible-admission-controllers/#prerequisites
apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingWebhookConfiguration
metadata:labels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: admission-webhookname: ingress-nginx-admission
webhooks:- name: validate.nginx.ingress.kubernetes.iomatchPolicy: Equivalentrules:- apiGroups:- networking.k8s.ioapiVersions:- v1beta1operations:- CREATE- UPDATEresources:- ingressesfailurePolicy: FailsideEffects: NoneadmissionReviewVersions:- v1- v1beta1clientConfig:service:namespace: ingress-nginxname: ingress-nginx-controller-admissionpath: /networking/v1beta1/ingresses
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/serviceaccount.yaml
apiVersion: v1
kind: ServiceAccount
metadata:name: ingress-nginx-admissionannotations:helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgradehelm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: admission-webhooknamespace: ingress-nginx
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/clusterrole.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:name: ingress-nginx-admissionannotations:helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgradehelm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: admission-webhook
rules:- apiGroups:- admissionregistration.k8s.ioresources:- validatingwebhookconfigurationsverbs:- get- update
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/clusterrolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:name: ingress-nginx-admissionannotations:helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgradehelm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: admission-webhook
roleRef:apiGroup: rbac.authorization.k8s.iokind: ClusterRolename: ingress-nginx-admission
subjects:- kind: ServiceAccountname: ingress-nginx-admissionnamespace: ingress-nginx
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/role.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:name: ingress-nginx-admissionannotations:helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgradehelm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: admission-webhooknamespace: ingress-nginx
rules:- apiGroups:- ''resources:- secretsverbs:- get- create
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/rolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:name: ingress-nginx-admissionannotations:helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgradehelm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: admission-webhooknamespace: ingress-nginx
roleRef:apiGroup: rbac.authorization.k8s.iokind: Rolename: ingress-nginx-admission
subjects:- kind: ServiceAccountname: ingress-nginx-admissionnamespace: ingress-nginx
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/job-createSecret.yaml
apiVersion: batch/v1
kind: Job
metadata:name: ingress-nginx-admission-createannotations:helm.sh/hook: pre-install,pre-upgradehelm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: admission-webhooknamespace: ingress-nginx
spec:template:metadata:name: ingress-nginx-admission-createlabels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: admission-webhookspec:containers:- name: createimage: docker.io/jettech/kube-webhook-certgen:v1.5.1imagePullPolicy: IfNotPresentargs:- create- --host=ingress-nginx-controller-admission,ingress-nginx-controller-admission.$(POD_NAMESPACE).svc- --namespace=$(POD_NAMESPACE)- --secret-name=ingress-nginx-admissionenv:- name: POD_NAMESPACEvalueFrom:fieldRef:fieldPath: metadata.namespacerestartPolicy: OnFailureserviceAccountName: ingress-nginx-admissionsecurityContext:runAsNonRoot: truerunAsUser: 2000
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/job-patchWebhook.yaml
apiVersion: batch/v1
kind: Job
metadata:name: ingress-nginx-admission-patchannotations:helm.sh/hook: post-install,post-upgradehelm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: admission-webhooknamespace: ingress-nginx
spec:template:metadata:name: ingress-nginx-admission-patchlabels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: admission-webhookspec:containers:- name: patchimage: docker.io/jettech/kube-webhook-certgen:v1.5.1imagePullPolicy: IfNotPresentargs:- patch- --webhook-name=ingress-nginx-admission- --namespace=$(POD_NAMESPACE)- --patch-mutating=false- --secret-name=ingress-nginx-admission- --patch-failure-policy=Failenv:- name: POD_NAMESPACEvalueFrom:fieldRef:fieldPath: metadata.namespacerestartPolicy: OnFailureserviceAccountName: ingress-nginx-admissionsecurityContext:runAsNonRoot: truerunAsUser: 2000
