k8s之ingress
一、k8s的暴露服务的方式存在很多种，为啥要选择ingress呢？
二、k8s之Service
apiVersion: v1 kind: Service metadata: name: xbd-nacos spec: ports: - port: 8848 targetPort: 8848 selector: app: xbd-nacos type: ClusterIP
类型：
1）ClusterIP：默认的，仅在集群内可用。
2）NodePort：暴露端口到节点，提供了集群外部访问的入口，端口范围固定 30000 ~ 32767。
3）LoadBalancer：使用支持外部负载均衡器的云提供商的服务，设置 type 的值为 "LoadBalancer"，将为 Service 提供负载均衡器。 负载均衡器是异步创建的，关于被提供的负载均衡器的信息将会通过 Service 的 status.loadBalancer 字段被发布出去。
4）Headless：适合数据库。clusterIp 设置为 None 就变成 Headless 了，不会再分配 IP。
5）ExternalName：把集群外部的服务引入到集群内部来，在集群内部直接使用。没有任何类型代理被创建，这只有 Kubernetes 1.7或更高版本的kube-dns才支持。
三、不使用service来做暴露的原因
Service能够提供负载均衡的能力，但是在使用上有以下限制：只提供 4 层负载均衡能力，而没有 7 层功能，但有时我们可能需要更多的匹配规则来转发请求，这点上 4 层负载均衡是不支持的。
Service理解：Kubernetes Service定义了这样一种抽象： Service是一种可以访问 Pod逻辑分组的策略， Service通常是通过 Label Selector访问 Pod组。
四、Ingress
Ingress 为外部访问集群提供了一个 统一 入口，避免了对外暴露集群端口；功能类似 Nginx，可以根据域名、路径把请求转发到不同的 Service。
ingress理解：基本上就看成nginx就行了。
五、Ingress安装
1）安装ingress控制器，由于ingress默认是不存在控制器的，所以需要自己安装ingress控制器。
控制器类型：Kubernetes、NGINX、Kong、Traefik、HAProxy、Voyager、Contour、Istio、Ambassador、Gloo、Skipper等
2）这里我们选择最熟悉的nginx来作为我们的控制器，官网地址和版本选择
地址：https://kubernetes.github.io/ingress-nginx/
github地址：https://github.com/kubernetes/ingress-nginx
版本：（因为我k8s的版本使用的是1.20.x,所有我选择的版本是v1.1.3）
3）安装ingress-nginx-controller
下载应用文件：
下载后不能直接使用，主要是镜像和一些配置需要修改。
修改后：
apiVersion: v1 kind: Namespace metadata: labels: app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx name: ingress-nginx --- apiVersion: v1 automountServiceAccountToken: true kind: ServiceAccount metadata: labels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.3 name: ingress-nginx namespace: ingress-nginx --- apiVersion: v1 kind: ServiceAccount metadata: labels: app.kubernetes.io/component: admission-webhook app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.3 name: ingress-nginx-admission namespace: ingress-nginx --- apiVersion: rbac.authorization.k8s.io/v1 kind: Role metadata: labels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.3 name: ingress-nginx namespace: ingress-nginx rules: - 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/v1 kind: Role metadata: labels: app.kubernetes.io/component: admission-webhook app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.3 name: ingress-nginx-admission namespace: ingress-nginx rules: - apiGroups: - "" resources: - secrets verbs: - get - create --- apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRole metadata: labels: app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.3 name: ingress-nginx rules: - 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/v1 kind: ClusterRole metadata: labels: app.kubernetes.io/component: admission-webhook app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.3 name: ingress-nginx-admission rules: - apiGroups: - admissionregistration.k8s.io resources: - validatingwebhookconfigurations verbs: - get - update --- apiVersion: rbac.authorization.k8s.io/v1 kind: RoleBinding metadata: labels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.3 name: ingress-nginx namespace: ingress-nginx roleRef: apiGroup: rbac.authorization.k8s.io kind: Role name: ingress-nginx subjects: - kind: ServiceAccount name: ingress-nginx namespace: ingress-nginx --- apiVersion: rbac.authorization.k8s.io/v1 kind: RoleBinding metadata: labels: app.kubernetes.io/component: admission-webhook app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.3 name: ingress-nginx-admission namespace: ingress-nginx roleRef: apiGroup: rbac.authorization.k8s.io kind: Role name: ingress-nginx-admission subjects: - kind: ServiceAccount name: ingress-nginx-admission namespace: ingress-nginx --- apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRoleBinding metadata: labels: app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.3 name: ingress-nginx roleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: ingress-nginx subjects: - kind: ServiceAccount name: ingress-nginx namespace: ingress-nginx --- apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRoleBinding metadata: labels: app.kubernetes.io/component: admission-webhook app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.3 name: ingress-nginx-admission roleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: ingress-nginx-admission subjects: - kind: ServiceAccount name: ingress-nginx-admission namespace: ingress-nginx --- apiVersion: v1 data: allow-snippet-annotations: "true" kind: ConfigMap metadata: labels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.3 name: ingress-nginx-controller namespace: ingress-nginx --- apiVersion: v1 kind: Service metadata: labels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.3 name: ingress-nginx-controller namespace: ingress-nginx spec: externalTrafficPolicy: Local ports: - appProtocol: http name: http port: 80 protocol: TCP targetPort: http - appProtocol: https name: https port: 443 protocol: TCP targetPort: https selector: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx type: LoadBalancer --- apiVersion: v1 kind: Service metadata: labels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.3 name: ingress-nginx-controller-admission namespace: ingress-nginx spec: ports: - appProtocol: https name: https-webhook port: 443 targetPort: webhook selector: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx type: ClusterIP --- apiVersion: apps/v1 kind: DaemonSet metadata: labels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.3 name: ingress-nginx-controller namespace: ingress-nginx spec: minReadySeconds: 0 revisionHistoryLimit: 10 selector: matchLabels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx template: metadata: labels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx spec: hostNetwork: true 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: registry.aliyuncs.com/google_containers/nginx-ingress-controller:v1.1.3 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/v1 kind: Job metadata: labels: app.kubernetes.io/component: admission-webhook app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.3 name: ingress-nginx-admission-create namespace: ingress-nginx spec: template: metadata: labels: app.kubernetes.io/component: admission-webhook app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.3 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: registry.aliyuncs.com/google_containers/kube-webhook-certgen:v1.1.1 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/v1 kind: Job metadata: labels: app.kubernetes.io/component: admission-webhook app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.3 name: ingress-nginx-admission-patch namespace: ingress-nginx spec: template: metadata: labels: app.kubernetes.io/component: admission-webhook app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.3 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: registry.aliyuncs.com/google_containers/kube-webhook-certgen:v1.1.1 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/v1 kind: IngressClass metadata: labels: app.kubernetes.io/component: controller app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.3 name: nginx spec: controller: k8s.io/ingress-nginx --- apiVersion: admissionregistration.k8s.io/v1 kind: ValidatingWebhookConfiguration metadata: labels: app.kubernetes.io/component: admission-webhook app.kubernetes.io/instance: ingress-nginx app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx app.kubernetes.io/version: 1.1.3 name: ingress-nginx-admission webhooks: - 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: None
主要修改点：
镜像
image: k8s.gcr.io/ingress-nginx/controller:v1.1.3@sha256:31f47c1e202b39fadecf822a9b76370bd4baed199a005b3e7d4d1455f4fd3fe2 改成 image: registry.aliyuncs.com/google_containers/nginx-ingress-controller:v1.1.3
image: k8s.gcr.io/ingress-nginx/kube-webhook-certgen:v1.1.1@sha256:64d8c73dca984af206adf9d6d7e46aa550362b1d7a01f3a0a91b20cc67868660 改成(这个镜像存在两处) image: registry.aliyuncs.com/google_containers/kube-webhook-certgen:v1.1.1
ingress-nginx-controller中的 kind: Deployment 改成 kind: DaemonSet # 保证每个节点都存在 --- spec: containers: ... 加入 spec: hostNetwork: true # 宿主网络开启 containers: ...
4）执行安装
kubectl apply -f deploy.yaml
五、编写Ingress
apiVersion: networking.k8s.io/v1 kind: Ingress metadata: name: xbd-nacos-ing spec: ingressClassName: "nginx" rules: - host: xbd.nacos.com http: paths: - path: / pathType: Prefix backend: service: name: xbd-nacos port: number: 8848
应用
kubectl apply -f xbd-nacos-ing.yaml
六、hosts加入
192.168.5.201 xbd.nacos.com
七、测试：
八、代理前缀处理
apiVersion: networking.k8s.io/v1 kind: Ingress metadata: name: xbd-nacos-ing spec: ingressClassName: "nginx" nginx.ingress.kubernetes.io/configuration-snippet: | rewrite ^/nacos/(.*)$ /$1 break; rules: - host: xbd.nacos.com http: paths: - path: /nacos pathType: Prefix backend: service: name: xbd-nacos port: number: 8848
