一、概述
二、Ingress 和 Pod 的关系
三、Ingress 工作流程
四、如何使用 Ingress
五、使用 Ingress 暴露 Nginx 应用

一、概述

在 K8s 的 Service 中我们说到, 因为每个 Pod 的 IP 是不固定的, 所以引入 Service 提供一组 Pod 的负载均衡, 通过把端口号对外暴露(type=NodePort), 使用 IP:Port 的方式进行访问

这样(type=NodePort)有一个缺陷, 在每一个节点上都会起端口, 在访问的时候通过任何节点, 通过该节点 IP:Port 访问, 这就意味着, 每个端口只能使用一次, 一个端口对应一个应用

在实际中, 都是通过域名访问, 根据不同域名跳转到不同的服务端口中.

二、Ingress 和 Pod 的关系

Pod 和 Ingress 通过 Service 关联的
Ingress 作为统一入口, 由 Service 关联一组 Pod

三、Ingress 工作流程

四、如何使用 Ingress

步骤一: 部署 Ingress Controller

步骤二: 创建 Ingress 规则

五、使用 Ingress 暴露 Nginx 应用

5.1 创建

创建 Nginx 应用, 对外暴露端口使用 NodePort

$ kubectl create deployment web --image=nginx
deployment.apps/web created

$ kubectl expose deployment web --port=80 --target-port=80 --type=NodePort
service/web exposed

$ kubectl get pod,svc
NAME                       READY   STATUS              RESTARTS   AGE
pod/web-5dcb957ccc-6vp68   0/1     ContainerCreating   0          28s

NAME                 TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
service/kubernetes   ClusterIP   10.96.0.1       <none>        443/TCP        9d
service/web          NodePort    10.104.91.244   <none>        80:30760/TCP   9s

5.2 部署

部署 Ingress Controller

创建 ingress-con.yaml 文件

$ vim ingress-con.yaml
apiVersion: v1
kind: Namespace
metadata:
  name: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx

---

kind: ConfigMap
apiVersion: v1
metadata:
  name: nginx-configuration
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx

---
kind: ConfigMap
apiVersion: v1
metadata:
  name: tcp-services
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx

---
kind: ConfigMap
apiVersion: v1
metadata:
  name: udp-services
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx

---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: nginx-ingress-serviceaccount
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
metadata:
  name: nginx-ingress-clusterrole
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
rules:
  - apiGroups:
      - ""
    resources:
      - configmaps
      - endpoints
      - nodes
      - pods
      - secrets
    verbs:
      - list
      - watch
  - apiGroups:
      - ""
    resources:
      - nodes
    verbs:
      - get
  - apiGroups:
      - ""
    resources:
      - services
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - ""
    resources:
      - events
    verbs:
      - create
      - patch
  - apiGroups:
      - "extensions"
      - "networking.k8s.io"
    resources:
      - ingresses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - "extensions"
      - "networking.k8s.io"
    resources:
      - ingresses/status
    verbs:
      - update

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: Role
metadata:
  name: nginx-ingress-role
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
rules:
  - apiGroups:
      - ""
    resources:
      - configmaps
      - pods
      - secrets
      - namespaces
    verbs:
      - get
  - apiGroups:
      - ""
    resources:
      - configmaps
    resourceNames:
      # Defaults to "<election-id>-<ingress-class>"
      # Here: "<ingress-controller-leader>-<nginx>"
      # This has to be adapted if you change either parameter
      # when launching the nginx-ingress-controller.
      - "ingress-controller-leader-nginx"
    verbs:
      - get
      - update
  - apiGroups:
      - ""
    resources:
      - configmaps
    verbs:
      - create
  - apiGroups:
      - ""
    resources:
      - endpoints
    verbs:
      - get

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: RoleBinding
metadata:
  name: nginx-ingress-role-nisa-binding
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: nginx-ingress-role
subjects:
  - kind: ServiceAccount
    name: nginx-ingress-serviceaccount
    namespace: ingress-nginx

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: nginx-ingress-clusterrole-nisa-binding
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: nginx-ingress-clusterrole
subjects:
  - kind: ServiceAccount
    name: nginx-ingress-serviceaccount
    namespace: ingress-nginx

---

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-ingress-controller
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
spec:
  replicas: 1
  selector:
    matchLabels:
      app.kubernetes.io/name: ingress-nginx
      app.kubernetes.io/part-of: ingress-nginx
  template:
    metadata:
      labels:
        app.kubernetes.io/name: ingress-nginx
        app.kubernetes.io/part-of: ingress-nginx
      annotations:
        prometheus.io/port: "10254"
        prometheus.io/scrape: "true"
    spec:
      hostNetwork: true
      # wait up to five minutes for the drain of connections
      terminationGracePeriodSeconds: 300
      serviceAccountName: nginx-ingress-serviceaccount
      nodeSelector:
        kubernetes.io/os: linux
      containers:
        - name: nginx-ingress-controller
          image: lizhenliang/nginx-ingress-controller:0.30.0
          args:
            - /nginx-ingress-controller
            - --configmap=$(POD_NAMESPACE)/nginx-configuration
            - --tcp-services-configmap=$(POD_NAMESPACE)/tcp-services
            - --udp-services-configmap=$(POD_NAMESPACE)/udp-services
            - --publish-service=$(POD_NAMESPACE)/ingress-nginx
            - --annotations-prefix=nginx.ingress.kubernetes.io
          securityContext:
            allowPrivilegeEscalation: true
            capabilities:
              drop:
                - ALL
              add:
                - NET_BIND_SERVICE
            # www-data -> 101
            runAsUser: 101
          env:
            - name: POD_NAME
              valueFrom:
                fieldRef:
                  fieldPath: metadata.name
            - name: POD_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
          ports:
            - name: http
              containerPort: 80
              protocol: TCP
            - name: https
              containerPort: 443
              protocol: TCP
          livenessProbe:
            failureThreshold: 3
            httpGet:
              path: /healthz
              port: 10254
              scheme: HTTP
            initialDelaySeconds: 10
            periodSeconds: 10
            successThreshold: 1
            timeoutSeconds: 10
          readinessProbe:
            failureThreshold: 3
            httpGet:
              path: /healthz
              port: 10254
              scheme: HTTP
            periodSeconds: 10
            successThreshold: 1
            timeoutSeconds: 10
          lifecycle:
            preStop:
              exec:
                command:
                  - /wait-shutdown

---

apiVersion: v1
kind: LimitRange
metadata:
  name: ingress-nginx
  namespace: ingress-nginx
  labels:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/part-of: ingress-nginx
spec:
  limits:
  - min:
      memory: 90Mi
      cpu: 100m
    type: Container

部署

$ kubectl apply -f ingress-con.yaml 
namespace/ingress-nginx created
configmap/nginx-configuration created
configmap/tcp-services created
configmap/udp-services created
serviceaccount/nginx-ingress-serviceaccount created
clusterrole.rbac.authorization.k8s.io/nginx-ingress-clusterrole created
role.rbac.authorization.k8s.io/nginx-ingress-role created
rolebinding.rbac.authorization.k8s.io/nginx-ingress-role-nisa-binding created
clusterrolebinding.rbac.authorization.k8s.io/nginx-ingress-clusterrole-nisa-binding created
deployment.apps/nginx-ingress-controller created
limitrange/ingress-nginx created

查看 Ingress Controller 状态

$ kubectl get pod -n ingress-nginx
NAME                                       READY   STATUS    RESTARTS   AGE
nginx-ingress-controller-766fb9f77-tgqt4   1/1     Running   0          42s

5.3 创建 Ingress 规则

创建规则 Yaml 文件

$ vim ingress-h.yaml
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: example-ingress
spec:
  rules:
  - host: example.ingredemo.com
    http:
      paths:
      - path: /
        backend:
          serviceName: web
          servicePort: 80

部署规则 Yaml 文件

$ kubectl apply -f ingress-h.yaml 
ingress.networking.k8s.io/example-ingress created

5.4 在浏览器中访问

$ kubectl get pods -n ingress-nginx -o wide
NAME                                       READY   STATUS    RESTARTS   AGE   IP                NODE        NOMINATED NODE   READINESS GATES
nginx-ingress-controller-766fb9f77-tgqt4   1/1     Running   0          11m   192.168.220.122   k8s-node1   <none>           <none>

$ kubectl get ingress
NAME              CLASS    HOSTS                   ADDRESS   PORTS   AGE
example-ingress   <none>   example.ingredemo.com             80      9m58s

在 window 的 Hosts 文件中添加一行 <IP> HOSTS, 例如我这是: 192.168.220.122 example.ingredemo.com

在浏览器中输入: example.ingredemo.com, 即可访问到 Nginx 页面

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k8s-Ingress.md

k8s-Ingress.md

一、概述

二、Ingress 和 Pod 的关系

三、Ingress 工作流程

四、如何使用 Ingress

五、使用 Ingress 暴露 Nginx 应用

5.1 创建

5.2 部署

5.3 创建 Ingress 规则

5.4 在浏览器中访问

Files

k8s-Ingress.md

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History

k8s-Ingress.md

File metadata and controls

一、概述

二、Ingress 和 Pod 的关系

三、Ingress 工作流程

四、如何使用 Ingress

五、使用 Ingress 暴露 Nginx 应用

5.1 创建

5.2 部署

5.3 创建 Ingress 规则

5.4 在浏览器中访问