Kubernetes服務網絡Ingress網絡模型分析、安裝和高級用法

文章目錄

- - 1、Ingres簡介
  - 2、Ingres網絡模型分析
  - 3、安裝Ingress
  - 4、使用
  - - 4.1、搭建測試環境
    - 4.2、域名訪問
    - 4.3、路徑重寫（高級用法）
    - 4.4、流量限制（高級用法）
  - 5、總結

1、Ingres簡介

Ingress翻譯過來是“入口”的意思，也就是說：K8S希望Ingress能成為整個k8s集群的流量入口；Ingress網絡是一組規則，充當Kubernetes集群的入口點。

Ingress：Service的統一網關入口
Service：Pod的統一網關入口

所有流量首先進入Ingress，由Ingress轉交給Service，最終由Service負載均衡后交到各個Pod應用。

Ingress其實就是nginx封裝的一個API對象。，通常通過HTTP管理集群中服務的外部訪問，是暴露服務的最有效方式。

2、Ingres網絡模型分析

舉例說明：

某個產品有三個服務：分別為訂單服務+用戶服務+產品服務
部署三臺機子

訂單服務：部署了兩個Pod應用分別在兩臺機子
用戶服務：部署了三個Pod應用分別在三臺機子
產品服務：部署了三個Pod應用分別在三臺機子

首先形成了兩層網絡服務，如下圖：

Service層網絡
Pod層網絡

通過增加Ingress網絡層，統一Service網絡層的網關。
在這里插入圖片描述

最終形成三層網絡的架構設計。

Ingres網絡層（最外層）
Service網絡層
Pod網絡層

3、安裝Ingress

wget https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v0.47.0/deploy/static/provider/baremetal/deploy.yaml#修改鏡像
vi deploy.yaml
#將image的值改為如下值：
registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/ingress-nginx-controller:v0.46.0# 檢查安裝的結果
kubectl get pod,svc -n ingress-nginx# 最后別忘記把svc暴露的端口要放行

注意兩點：

下載yml文件
修改阿里云的鏡像地址

使用yml進行安裝Ingress
在集群中安裝完Ingress后，會生成service，暴露兩個端口供外部訪問。

http /https

以NodePort方式暴露外部訪問的端口

在這里插入圖片描述

4、使用

官網地址：https://kubernetes.github.io/ingress-nginx/

4.1、搭建測試環境

測試環境：應用如下yaml，準備好測試環境

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說明：

以Deployment方式部署了兩個應用，分別為：

hello-server：鏡像名hello-server：兩個副本，暴露端口8000，目標端口9000
nginx-demo：鏡像名nginx：兩個副本，暴露端口8000，目標端口80

同時也生成對應的兩個service，分別為：nginx-demo和hello-serve

4.2、域名訪問

通過下面的yml文件，創建一個ingress資源。

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"  # 把請求會轉給下面的服務，下面的服務一定要能處理這個路徑，不能處理就是404backend:service:name: nginx-demo  ## java，比如使用路徑重寫，去掉前綴nginxport:number: 8000

訪問規則描述：

訪問域名hello.atguigu.com，會轉到service：hello-server應用
訪問域名demo.atguigu.com/nginx，會轉到service：nginx-demo應用

問題： path: “/nginx” 與 path: “/” 為什么會有不同的效果？

回答：上述yaml中加了路徑/nginx，如果訪問域名中也加了/nginx路徑，說明訪問域名路徑一直，Ingress會處理這個路徑請求，然后轉發到service層nginx-demo，從而service層nginx-demo將請求流量負載均衡到各個pod；如果訪問域名路徑不一致，Ingress就不能處理這個路徑，也就起不到轉發路由的作用，因為ingress本身就是nginx，所以頁面也會顯示nginx的404，但不一樣的是：此時nginx不帶版本號。

4.3、路徑重寫（高級用法）

apiVersion: networking.k8s.io/v1
kind: Ingress  
metadata:annotations:nginx.ingress.kubernetes.io/rewrite-target: /$2name: ingress-host-bar
spec:ingressClassName: nginxrules:- host: "hello.atguigu.com"http:paths:- pathType: Prefixpath: "/"backend:service:name: hello-serverport:number: 8000- host: "demo.atguigu.com"http:paths:- pathType: Prefixpath: "/nginx(/|$)(.*)"  # 把請求會轉給下面的服務，下面的服務一定要能處理這個路徑，不能處理就是404backend:service:name: nginx-demo  ## java，比如使用路徑重寫，去掉前綴nginxport:number: 8000

在這里插入圖片描述

4.4、流量限制（高級用法）

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

說明：

exact：精確匹配路徑類型
配置rps每秒請求接受的請求數為1

如果超過配置中的限制，訪問就會報503的錯誤，起到限流的作用。
在這里插入圖片描述

5、總結

最終，k8s集群網絡模型包括三層網絡模型構成，即：

Ingress層
Service層
Pod層

另外在實際工作中，也可以在Ingress層外部設置一個LoadBalance層，請求流量首先經過外部的LB負載均衡到各個機子，然后在Ingress、Service和Pod層之間傳遞。
在這里插入圖片描述

附錄：ingress-nginx安裝的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