nginx ingress代理websocket流量

1 概述： 1.1 环境

版本信息如下：
a、操作系统：centos 7.6
b、kubernetes版本：v1.15.0
c、ingress nginx版本：0.47.0

2 nginx ingress是否支持代理websocket流量

nginx ingress 默认支持websocket协议，因此ingress实例不需要额外配置。
值得注意的是，proxy-read-timeout和proxy-send-timeout的默认值是60秒，应该根据实际情况增加此两个参数的值。如果使用默认值60，则websocket客户端超过60秒没有给websocket服务端发送信息，再次发送数据时是无效的，例如使用websocat命令时，出现WebSocketError: I/O failure。

3 ingress样例

apiVersion: extensions/v1beta1kind: Ingressmetadata:  annotations:    # 根据实际情况调整超时时间，默认值为60    nginx.ingress.kubernetes.io/proxy-read-timeout: "600"    nginx.ingress.kubernetes.io/proxy-send-timeout: "600"  name: ws  namespace: defaultspec:  rules:  - host: apigateway    http:      paths:      - backend:          serviceName: ws          servicePort: 3000        path: /

4 部署 4.1 部署nginx ingress

将以下文件进行kubectl apply，本案例中是以daemonset形式部署nginx controller，使用host网络。

apiVersion: v1kind: Namespacemetadata:  name: ingress-nginx  labels:    app.kubernetes.io/name: ingress-nginx    app.kubernetes.io/part-of: ingress-nginx---kind: ConfigMapapiVersion: v1metadata:  name: nginx-configuration  namespace: ingress-nginx  labels:    app.kubernetes.io/name: ingress-nginx    app.kubernetes.io/part-of: ingress-nginx---kind: ConfigMapapiVersion: v1metadata:  name: tcp-services  namespace: ingress-nginx  labels:    app.kubernetes.io/name: ingress-nginx    app.kubernetes.io/part-of: ingress-nginx---kind: ConfigMapapiVersion: v1metadata:  name: udp-services  namespace: ingress-nginx  labels:    app.kubernetes.io/name: ingress-nginx    app.kubernetes.io/part-of: ingress-nginx---apiVersion: v1data:  resolv.conf: |    nameserver 10.96.0.10    search default.svc.cluster.local svc.cluster.local cluster.local lj.io    options ndots:5kind: ConfigMapmetadata:  name: resolver  namespace: ingress-nginx---apiVersion: v1kind: ServiceAccountmetadata:  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/v1beta1kind: ClusterRolemetadata:  name: nginx-ingress-clusterrole  labels:    app.kubernetes.io/name: ingress-nginx    app.kubernetes.io/part-of: ingress-nginxrules:  - apiGroups:      - ""    resources:      - configmaps      - endpoints      - nodes      - pods      - secrets    verbs:      - list      - watch  - apiGroups:      - ""    resources:      - nodes    verbs:      - get  - apiGroups:      - ""    resources:      - services    verbs:      - get      - list      - watch  - apiGroups:      - "extensions"      - "networking.k8s.io"    resources:      - ingresses    verbs:      - get      - list      - watch      - update  - apiGroups:      - ""    resources:      - events    verbs:      - create      - patch  - apiGroups:      - "extensions"    resources:      - ingresses/status    verbs:      - update---apiVersion: rbac.authorization.k8s.io/v1beta1kind: Rolemetadata:  name: nginx-ingress-role  namespace: ingress-nginx  labels:    app.kubernetes.io/name: ingress-nginx    app.kubernetes.io/part-of: ingress-nginxrules:  - 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/v1beta1kind: RoleBindingmetadata:  name: nginx-ingress-role-nisa-binding  namespace: ingress-nginx  labels:    app.kubernetes.io/name: ingress-nginx    app.kubernetes.io/part-of: ingress-nginxroleRef:  apiGroup: rbac.authorization.k8s.io  kind: Role  name: nginx-ingress-rolesubjects:  - kind: ServiceAccount    name: nginx-ingress-serviceaccount    namespace: ingress-nginx---apiVersion: rbac.authorization.k8s.io/v1beta1kind: ClusterRoleBindingmetadata:  name: nginx-ingress-clusterrole-nisa-binding  labels:    app.kubernetes.io/name: ingress-nginx    app.kubernetes.io/part-of: ingress-nginxroleRef:  apiGroup: rbac.authorization.k8s.io  kind: ClusterRole  name: nginx-ingress-clusterrolesubjects:  - kind: ServiceAccount    name: nginx-ingress-serviceaccount    namespace: ingress-nginx---apiVersion: v1kind: Servicemetadata:  name: ingress-nginx  namespace: ingress-nginxspec:  ports:  - port: 80    protocol: TCP    targetPort: 80  selector:    app.kubernetes.io/name: ingress-nginx  sessionAffinity: None  type: ClusterIP---apiVersion: apps/v1kind: DaemonSetmetadata:  name: nginx-ingress-controller  namespace: ingress-nginx  labels:    app.kubernetes.io/name: ingress-nginx    app.kubernetes.io/part-of: ingress-nginxspec:  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:      serviceAccountName: nginx-ingress-serviceaccount      hostNetwork: true      dnsPolicy: ClusterFirstWithHostNet      containers:        - name: nginx-ingress-controller          image: bitnami/nginx-ingress-controller:0.47.0          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 -> 33            runAsUser: 33          env:            - name: POD_NAME              valueFrom:                fieldRef:                  fieldPath: metadata.name            - name: POD_NAMESPACE              valueFrom:                fieldRef:                  fieldPath: metadata.namespace          ports:            - name: http              containerPort: 80            - name: https              containerPort: 443          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

部署效果如下，

4.2 设置域名

在本案例中使用/etc/hosts文件解析域名，本机机器IP是192.168.0.70。

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4::1         localhost localhost.localdomain localhost6 localhost6.localdomain6192.168.0.70 apigateway 

4.3 部署websocket服务端

服务端进程监听的端口是3000，是简单的echo server。

apiVersion: apps/v1kind: Deploymentmetadata:  labels:    app: ws  name: ws  namespace: defaultspec:  replicas: 1  selector:    matchLabels:      app: ws  template:    metadata:      labels:        app: ws    spec:      containers:      - image: elegantmonkeys/websockets-demo:latest        imagePullPolicy: IfNotPresent        name: echo        ports:        - containerPort: 3000          protocol: TCP        resources:          limits:            cpu: "0.2"            memory: 100Mi          requests:            cpu: 100m            memory: 100Mi---apiVersion: v1kind: Servicemetadata:  labels:    app: ws  name: ws  namespace: defaultspec:  ports:  - name: ws    port: 3000    protocol: TCP    targetPort: 3000  selector:    app: ws  type: NodePort

4.4 创建ingress资源

apiVersion: extensions/v1beta1kind: Ingressmetadata:  annotations:    # 根据实际情况调整超时时间，默认值为60    nginx.ingress.kubernetes.io/proxy-read-timeout: "600"    nginx.ingress.kubernetes.io/proxy-send-timeout: "600"  name: ws  namespace: defaultspec:  rules:  - host: apigateway    http:      paths:      - backend:          serviceName: ws          servicePort: 3000        path: /

4.5 下载websockt客户端

cd /tmpwget -O websocat https://github.com/vi/websocat/releases/download/v1.9.0/websocat_linux64chmod 755 websocat mv websocat /usr/bin/

4.6 测试

使用websocat命令通过ingress nginx连接echo server。

5 小结：

ingress nginx默认支持websocket协议，使用长连接协议时需要注意连接超时的设置，读取和发送超时的注解参数分别是：nginx.ingress.kubernetes.io/proxy-read-timeout和nginx.ingress.kubernetes.io/proxy-send-timeout。