本篇主要记录一下 k8s 新版本 1.23.5 中如何搭建 ingress controller 以及里面的注意项
新版本和老版本 区别有不少 ，坑很多，只能从官网一点点撸
目录
1.环境准备
操作系统：Centos7 （CentOS Linux release 7.9.2009）
Master 主节点：1台 虚拟机
Node 计算节点：2台 虚拟机
K8s version：v1.23.5 （选的较新的版本）
Docker version：20.10.14
环境和上一篇中 kubeadm 搭建 k8s 的一致
2.概述
下面从 官网摘取的对于 Ingress 的介绍
2.1 什么是 IngressIngress 是对集群中服务的外部访问进行管理的 API 对象，典型的访问方式是 HTTP。Ingress 可以提供负载均衡
Ingress 公开了从集群外部到集群内服务的 HTTP 和 HTTPS 路由。流量路由由 Ingress 资源上定义的规则控制。
下面是一个将所有流量都发送到同一 Service 的简单 Ingress 示例：
但是 仅创建 Ingress 资源本身没有任何效果，需要有对应的 Ingress 控制器 ，你可能需要部署 Ingress 控制器，例如 ingress-nginx。你可以从许多 Ingress 控制器 中进行选择。
2.2 什么是 Ingress controller为了让 Ingress 资源工作，集群必须有一个正在运行的 Ingress 控制器。k8s官网维护了 3 个Ingress控制器
目前支持和维护 AWS、 GCE 和 Nginx Ingress 控制器 ，本篇就拿 Ingress-nginx 作为控制器为例 讲解一下如何部署
还有一些 社区等提供的 控制器
3.部署 Ingress-nginx controller
本篇就拿 最常用的 Ingress-nginx 作为 Ingress的控制器，实现k8s 把请求重定向到集群内部（Cluster Ip）服务去
3.1 deploy.yaml 坑点Ingress-nginx 官网 提到了 deploy.yaml 文件
Ingress-nginx 新版本的 depoly.yaml 有些不同，需要拉取下面2个镜像
k8s.gcr.io/ingress-nginx/controller:v1.1.2
k8s.gcr.io/ingress-nginx/kube-webhook-certgen:v1.1.1
多半是下载不到的，所以需要 自己替换一下 ，可以去docker hub 上找到对应的 镜像文件
总结 坑点：
新版本中 提供了 IngressClass ，需要在编写 Ingress 的时候指定
Image 加载不到，需要手动去 docker hub 上找其他的 并且修改 deploy.yaml文件
把 ingress-nginx-controller 使用 hostNetwork: true 进行部署 比 NodePort 减少一层转发，但是需要指定 选择打了标签的 node nodeSelector: app: ingress
3.2 deploy.yaml 样例（我自己修改后的 可以参考）#GENERATED FOR K8S 1.20apiVersion: v1kind: Namespacemetadata:labels: app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginxname: ingress-nginx---apiVersion: v1automountServiceAccountToken: truekind: ServiceAccountmetadata:labels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/managed-by: Helm app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.2 helm.sh/chart: ingress-nginx-4.0.18name: ingress-nginxnamespace: ingress-nginx---apiVersion: v1kind: ServiceAccountmetadata:annotations: helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade helm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels: app.kubernetes.io/component: admission-webhook app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/managed-by: Helm app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.2 helm.sh/chart: ingress-nginx-4.0.18name: ingress-nginx-admissionnamespace: ingress-nginx---apiVersion: rbac.authorization.k8s.io/v1kind: Rolemetadata:labels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/managed-by: Helm app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.2 helm.sh/chart: ingress-nginx-4.0.18name: ingress-nginxnamespace: ingress-nginxrules:- apiGroups: - "" resources: - namespaces verbs: - get- apiGroups: - "" resources: - configmaps - pods - secrets - endpoints verbs: - get - list - watch- apiGroups: - "" resources: - services verbs: - get - list - watch- apiGroups: - networking.k8s.io resources: - ingresses verbs: - get - list - watch- apiGroups: - networking.k8s.io resources: - ingresses/status verbs: - update- apiGroups: - networking.k8s.io resources: - ingressclasses verbs: - get - list - watch- apiGroups: - "" resourceNames: - ingress-controller-leader resources: - configmaps verbs: - get - update- apiGroups: - "" resources: - configmaps verbs: - create- apiGroups: - "" resources: - events verbs: - create - patch---apiVersion: rbac.authorization.k8s.io/v1kind: Rolemetadata:annotations: helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade helm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels: app.kubernetes.io/component: admission-webhook app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/managed-by: Helm app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.2 helm.sh/chart: ingress-nginx-4.0.18name: ingress-nginx-admissionnamespace: ingress-nginxrules:- apiGroups: - "" resources: - secrets verbs: - get - create---apiVersion: rbac.authorization.k8s.io/v1kind: ClusterRolemetadata:labels: app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/managed-by: Helm app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.2 helm.sh/chart: ingress-nginx-4.0.18name: ingress-nginxrules:- apiGroups: - "" resources: - configmaps - endpoints - nodes - pods - secrets - namespaces verbs: - list - watch- apiGroups: - "" resources: - nodes verbs: - get- apiGroups: - "" resources: - services verbs: - get - list - watch- apiGroups: - networking.k8s.io resources: - ingresses verbs: - get - list - watch- apiGroups: - "" resources: - events verbs: - create - patch- apiGroups: - networking.k8s.io resources: - ingresses/status verbs: - update- apiGroups: - networking.k8s.io resources: - ingressclasses verbs: - get - list - watch---apiVersion: rbac.authorization.k8s.io/v1kind: ClusterRolemetadata:annotations: helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade helm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels: app.kubernetes.io/component: admission-webhook app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/managed-by: Helm app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.2 helm.sh/chart: ingress-nginx-4.0.18name: ingress-nginx-admissionrules:- apiGroups: - admissionregistration.k8s.io resources: - validatingwebhookconfigurations verbs: - get - update---apiVersion: rbac.authorization.k8s.io/v1kind: RoleBindingmetadata:labels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/managed-by: Helm app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.2 helm.sh/chart: ingress-nginx-4.0.18name: ingress-nginxnamespace: ingress-nginxroleRef:apiGroup: rbac.authorization.k8s.iokind: Rolename: ingress-nginxsubjects:- kind: ServiceAccount name: ingress-nginx namespace: ingress-nginx---apiVersion: rbac.authorization.k8s.io/v1kind: RoleBindingmetadata:annotations: helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade helm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels: app.kubernetes.io/component: admission-webhook app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/managed-by: Helm app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.2 helm.sh/chart: ingress-nginx-4.0.18name: ingress-nginx-admissionnamespace: ingress-nginxroleRef:apiGroup: rbac.authorization.k8s.iokind: Rolename: ingress-nginx-admissionsubjects:- kind: ServiceAccount name: ingress-nginx-admission namespace: ingress-nginx---apiVersion: rbac.authorization.k8s.io/v1kind: ClusterRoleBindingmetadata:labels: app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/managed-by: Helm app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.2 helm.sh/chart: ingress-nginx-4.0.18name: ingress-nginxroleRef:apiGroup: rbac.authorization.k8s.iokind: ClusterRolename: ingress-nginxsubjects:- kind: ServiceAccount name: ingress-nginx namespace: ingress-nginx---apiVersion: rbac.authorization.k8s.io/v1kind: ClusterRoleBindingmetadata:annotations: helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgrade helm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels: app.kubernetes.io/component: admission-webhook app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/managed-by: Helm app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.2 helm.sh/chart: ingress-nginx-4.0.18name: ingress-nginx-admissionroleRef:apiGroup: rbac.authorization.k8s.iokind: ClusterRolename: ingress-nginx-admissionsubjects:- kind: ServiceAccount name: ingress-nginx-admission namespace: ingress-nginx---apiVersion: v1data:allow-snippet-annotations: "true"kind: ConfigMapmetadata:labels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/managed-by: Helm app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.2 helm.sh/chart: ingress-nginx-4.0.18name: ingress-nginx-controllernamespace: ingress-nginx---apiVersion: v1kind: Servicemetadata:labels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/managed-by: Helm app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.2 helm.sh/chart: ingress-nginx-4.0.18name: ingress-nginx-controllernamespace: ingress-nginxspec:externalTrafficPolicy: LocalipFamilies: - IPv4ipFamilyPolicy: SingleStackports: - appProtocol: http name: http port: 80 protocol: TCP targetPort: http - appProtocol: https name: https port: 443 protocol: TCP targetPort: httpsselector: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginxtype: LoadBalancer---apiVersion: v1kind: Servicemetadata:labels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/managed-by: Helm app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.2 helm.sh/chart: ingress-nginx-4.0.18name: ingress-nginx-controller-admissionnamespace: ingress-nginxspec:ports: - appProtocol: https name: https-webhook port: 443 targetPort: webhookselector: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginxtype: ClusterIP---apiVersion: apps/v1kind: Deploymentmetadata:labels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/managed-by: Helm app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.2 helm.sh/chart: ingress-nginx-4.0.18name: ingress-nginx-controllernamespace: ingress-nginxspec:minReadySeconds: 0revisionHistoryLimit: 10selector: matchLabels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginxtemplate: metadata: labels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx spec: hostNetwork: true #修改ingress-nginx-controller 为 hostNetwork模式 nodeSelector: #选择 node label 中有 app=ingress的节点进行部署 app: ingress containers: - args: - /nginx-ingress-controller - --publish-service=$(POD_NAMESPACE)/ingress-nginx-controller - --election-id=ingress-controller-leader - --controller-class=k8s.io/ingress-nginx - --ingress-class=nginx - --configmap=$(POD_NAMESPACE)/ingress-nginx-controller - --validating-webhook=:8443 - --validating-webhook-certificate=/usr/local/certificates/cert - --validating-webhook-key=/usr/local/certificates/key env: - name: POD_NAME valueFrom: fieldRef: fieldPath: metadata.name - name: POD_NAMESPACE valueFrom: fieldRef: fieldPath: metadata.namespace - name: LD_PRELOAD value: /usr/local/lib/libmimalloc.so image: k8s.gcr.io/ingress-nginx/controller:v1.1.2 #修改镜像地址 imagePullPolicy: IfNotPresent lifecycle: preStop: exec: command: - /wait-shutdown livenessProbe: failureThreshold: 5 httpGet: path: /healthz port: 10254 scheme: HTTP initialDelaySeconds: 10 periodSeconds: 10 successThreshold: 1 timeoutSeconds: 1 name: controller ports: - containerPort: 80 name: http protocol: TCP - containerPort: 443 name: https protocol: TCP - containerPort: 8443 name: webhook protocol: TCP readinessProbe: failureThreshold: 3 httpGet: path: /healthz port: 10254 scheme: HTTP initialDelaySeconds: 10 periodSeconds: 10 successThreshold: 1 timeoutSeconds: 1 resources: requests: cpu: 100m memory: 90Mi securityContext: allowPrivilegeEscalation: true capabilities: add: - NET_BIND_SERVICE drop: - ALL runAsUser: 101 volumeMounts: - mountPath: /usr/local/certificates/ name: webhook-cert readOnly: true dnsPolicy: ClusterFirst nodeSelector: kubernetes.io/os: linux serviceAccountName: ingress-nginx terminationGracePeriodSeconds: 300 volumes: - name: webhook-cert secret: secretName: ingress-nginx-admission---apiVersion: batch/v1kind: Jobmetadata:annotations: helm.sh/hook: pre-install,pre-upgrade helm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels: app.kubernetes.io/component: admission-webhook app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/managed-by: Helm app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.2 helm.sh/chart: ingress-nginx-4.0.18name: ingress-nginx-admission-createnamespace: ingress-nginxspec:template: metadata: labels: app.kubernetes.io/component: admission-webhook app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/managed-by: Helm app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.2 helm.sh/chart: ingress-nginx-4.0.18 name: ingress-nginx-admission-create spec: containers: - args: - create - --host=ingress-nginx-controller-admission,ingress-nginx-controller-admission.$(POD_NAMESPACE).svc - --namespace=$(POD_NAMESPACE) - --secret-name=ingress-nginx-admission env: - name: POD_NAMESPACE valueFrom: fieldRef: fieldPath: metadata.namespace image: k8s.gcr.io/ingress-nginx/kube-webhook-certgen:v1.1.1 #修改镜像地址 imagePullPolicy: IfNotPresent name: create securityContext: allowPrivilegeEscalation: false nodeSelector: kubernetes.io/os: linux restartPolicy: OnFailure securityContext: fsGroup: 2000 runAsNonRoot: true runAsUser: 2000 serviceAccountName: ingress-nginx-admission---apiVersion: batch/v1kind: Jobmetadata:annotations: helm.sh/hook: post-install,post-upgrade helm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels: app.kubernetes.io/component: admission-webhook app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/managed-by: Helm app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.2 helm.sh/chart: ingress-nginx-4.0.18name: ingress-nginx-admission-patchnamespace: ingress-nginxspec:template: metadata: labels: app.kubernetes.io/component: admission-webhook app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/managed-by: Helm app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.2 helm.sh/chart: ingress-nginx-4.0.18 name: ingress-nginx-admission-patch spec: containers: - args: - patch - --webhook-name=ingress-nginx-admission - --namespace=$(POD_NAMESPACE) - --patch-mutating=false - --secret-name=ingress-nginx-admission - --patch-failure-policy=Fail env: - name: POD_NAMESPACE valueFrom: fieldRef: fieldPath: metadata.namespace image: k8s.gcr.io/ingress-nginx/kube-webhook-certgen:v1.1.1 #修改镜像地址 imagePullPolicy: IfNotPresent name: patch securityContext: allowPrivilegeEscalation: false nodeSelector: kubernetes.io/os: linux restartPolicy: OnFailure securityContext: fsGroup: 2000 runAsNonRoot: true runAsUser: 2000 serviceAccountName: ingress-nginx-admission---apiVersion: networking.k8s.io/v1kind: IngressClassmetadata:labels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/managed-by: Helm app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.2 helm.sh/chart: ingress-nginx-4.0.18name: nginxspec:controller: k8s.io/ingress-nginx---apiVersion: admissionregistration.k8s.io/v1kind: ValidatingWebhookConfigurationmetadata:labels: app.kubernetes.io/component: admission-webhook app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/managed-by: Helm app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.2 helm.sh/chart: ingress-nginx-4.0.18name: ingress-nginx-admissionwebhooks:- admissionReviewVersions: - v1 clientConfig: service: name: ingress-nginx-controller-admission namespace: ingress-nginx path: /networking/v1/ingresses failurePolicy: Fail matchPolicy: Equivalent name: validate.nginx.ingress.kubernetes.io rules: - apiGroups: - networking.k8s.io apiVersions: - v1 operations: - CREATE - UPDATE resources: - ingresses sideEffects: None4.部署 Ingress-nginx
4.1 准备工作给 node2 节点打了app=ingress标签，因为上面的ingress-nginx-controller 使用的是 hostNetwork 模式（只会放pod真实pod 的 端口） + nodeSelector
kubectl label node kubec-node-2 app=ingress4.2 部署 kubect apply -fkubectl apply -f deploy.yaml #通过 kubectl apply 命令进行部署 ，前提是镜像准备好，否则GG4.3 查看状态kubectl get all -n ingress-nginx #查看 ingress-nginx namespace的 部署情况kubectl logs -f ingress-nginx-controller-744f6d5bdf-tl6g4 -n ingress-nginx # 查看 ingress-nginx-controller 的 日志情况4.4 测试访问直接访问 kube-node-2的 ip 即可，因为 ingress-nginx-controller 默认是 监听 80端口，由于上面的 nodeSelector: #选择 node label 中有 app=ingress的节点进行部署 ,而 kube-node-2 是被打了标签的节点node
可以看到 其实就是一个 nginx
5.部署一个 tomcat 测试 Ingress-nginx
通过部署一个tomcat ，测试Ingress-nginx的代理 是否生效
5.1 编写 deploy-tomcat.yaml主要编写
Deployment 部署tomcat:8.0-alpine，
Service 暴露 tomcat pod
一个 Ingress 资源它规定 访问 tomcat.demo.com 这个域名的 所有请求 / 都转发到 tomcat-demo Service 上
IngressClass 新版本提供的资源 ，用于在定义 Ingress资源的时候 指定，在集群中有多个 Ingress controller 的时候很有用处
apiVersion: apps/v1kind: Deploymentmetadata:name: tomcat-demospec:selector: matchLabels: app: tomcat-demoreplicas: 1template: metadata: labels: app: tomcat-demo spec: containers: - name: tomcat-demo image: tomcat:8.0-alpine ports: - containerPort: 8080---apiVersion: v1kind: Servicemetadata:name: tomcat-demospec:selector: app: tomcat-demo #选择 tomcat-demo pod ports:- port: 80 #对外暴露 80 端口 protocol: TCP targetPort: 8080 # tomcat 端口---apiVersion: networking.k8s.io/v1kind: Ingressmetadata:name: tomcat-demospec:defaultBackend: service: name: default-http-backend #！！！指定 默认的backend服务 port: number: 80 ingressClassName: nginx #！！！重点 需要指定 哪个 IngressClass 可以看上面的 deploy.yaml 最后定义的rules:- host: tomcat.demo.com #所有的tomcat.demo.com请求都转发到Service tomcat-demo http: paths: - pathType: Prefix path: "/" backend: service: name: tomcat-demo port: number: 80 ---#定义一个 default-http-backend 当没有被Ingress规定的请求 负载给 它apiVersion: apps/v1kind: Deploymentmetadata:name: default-http-backendlabels: app: default-http-backendspec:replicas: 1selector: matchLabels: app: default-http-backendtemplate: metadata: labels: app: default-http-backend spec: terminationGracePeriodSeconds: 60 containers: - name: default-http-backend # Any image is permissible as long as: # 1. It serves a 404 page at / # 2. It serves 200 on a /healthz endpoint image: registry.cn-hangzhou.aliyuncs.com/google_containers/defaultbackend:1.4 livenessProbe: httpGet: path: /healthz port: 8080 scheme: HTTP initialDelaySeconds: 30 timeoutSeconds: 5 ports: - containerPort: 8080 resources: limits: cpu: 10m memory: 20Mi requests: cpu: 10m memory: 20Mi--- apiVersion: v1kind: Servicemetadata:name: default-http-backendlabels: app: default-http-backendspec:ports:- port: 80 targetPort: 8080selector: app: default-http-backend5.2 部署 tomcat + ingress + default-http-backend部署上面的文件 即可
查看 部署情况 可以看到都是Running 了
5.3 测试 通过Ingress-nginx 能否访问到tomcat由于我们 ingress 资源配置的 域名 是 tomcat.demo.com ，所以我需要把它添加到 宿主机的hosts 文件中，如下
那么按照预期，当我访问 tomcat.demo.com 的时候其实就是访问 192.168.56.22 上的 ingress-nginx-controller 这个nginx，那么根据 ingress 的 资源的设定 它会把请求 转发到 Service tomcat-demo 上，从而访问到 tomcat 界面
当我访问 api.demo.com 的时候 由于没有对这个域名进行处理 那么会默认把请求转发到 default-http-backend 上
访问 tomcat.demo.com
访问 api.demo.com
总结
至此在k8s 1.23.5上 已经成功部署了 Ingress-nginx ，并且通过部署一个tomcat服务测试了 Ingress-nginx 已经代理成功了，由于不管是 k8s 新版本和 Ingress-nginx 新版本都有些变化 所有很些坑，是我从官网不断摸索的，下面总结一下坑点
image 镜像需要自己从docker hub 上准备好 ，或者直接修改Ingress-nginx 的 deploy.yaml
k8s.gcr.io/ingress-nginx/controller:v1.1.2
k8s.gcr.io/ingress-nginx/kube-webhook-certgen:v1.1.1
重要！新版本中 提供了 IngressClass ，需要在编写 Ingress 的时候指定
把 ingress-nginx-controller 使用 hostNetwork: true 进行部署 比 NodePort 减少一层转发，但是需要指定 选择打了标签的 node nodeSelector: app: ingress
通过 Ingress spec.defaultBackend 指定 默认服务，并且需要保持在同一个 namespace
spec:defaultBackend: service: name: default-http-backend #！！！指定 默认的backend服务 port: number: 80vscode k8s 插件 快捷生成Depoyment 的时候 自定添加了资源限制，导致部署tomcat的时候 总是启动不起来..
导致tomcat pod 状态 CrashLoopBackOff，从而导致 通过 Ingress-nginx 无法访问到tomcat
resources:limits: memory: "128Mi" #内存不够 部署tomcat 内存 cpu: "500m"欢迎大家访问个人博客 #/