Question

这是一个示例WebSocket应用，我正在尝试使其从Kubernetes ingress-nginx控制器运行。

Kubernetes yaml：

echo "
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: ws-example
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: wseg
    spec:
      containers:
      - name: websocketexample
        image: nicksardo/websocketexample
        imagePullPolicy: Always
        ports:
        - name: http
          containerPort: 8080
        env:
        - name: podname
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
---
apiVersion: v1
kind: Service
metadata:
  name: ws-example-svc
  labels:
    app: wseg
spec:
  type: NodePort
  ports:
  - port: 80
    targetPort: 8080
    protocol: TCP
  selector:
    app: wseg
---

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: ws-example-svc
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/rewrite-target: /
spec:
  rules:
  - host: myhostname.com
    http:
      paths:
      - backend:
          serviceName: ws-example-svc
          servicePort: 80
        path: /somecontext

" | kubectl create -f -

我收到此错误：

WebSocket connection to 'ws://myhostname.com/somecontext/ws?encoding=text' failed: Error during WebSocket handshake: Unexpected response code: 400

当我尝试使用像http://www.websocket.org/echo.html这样的WebSocket客户端网页进行连接时

ingress-nginx的版本为0.14.0。此版本支持WebSockets。

更新，当我从本地主机移植到pod的端口时，我能够直接访问websocket运行的pod。

[rpalaniappan@sdgl15280a331:~/git/zalenium] $ kubectl get pods -l app=wseg
NAME                          READY     STATUS    RESTARTS   AGE
ws-example-5dddb98cfb-vmdt5   1/1       Running   0          5h
[rpalaniappan@sdgl15280a331:~/git/zalenium] $ kubectl port-forward ws-example-5dddb98cfb-vmdt5 8080:8080
Forwarding from 127.0.0.1:8080 -> 8080
Forwarding from [::1]:8080 -> 8080
Handling connection for 8080

[rpalaniappan@sdgl15280a331:~/git/zalenium] $ wscat -c ws://localhost:8080/ws
connected (press CTRL+C to quit)
< Connected to ws-example-5dddb98cfb-vmdt5
> hi
< hi
< ws-example-5dddb98cfb-vmdt5 reports time: 2018-12-28 01:19:00.788098266 +0000 UTC

Answer 1

基本上就是这样：

nginx.ingress.kubernetes.io/rewrite-target: /

每次浏览器尝试发出WebSocket连接请求时，都会从发送到后端的请求中剥离/ws（与path: /ws组合）。后端在收到连接请求时期望/ws。

如果您指定path: /mypath和/mypath/*，则可以使用（对我有用）：

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: ws-example-svc
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/rewrite-target: /
spec:
  rules:
  - host: myhostname.com
    http:
      paths:
      - backend:
          serviceName: ws-example-svc
          servicePort: 80
        path: /mypath
      - backend:
          serviceName: ws-example-svc
          servicePort: 80
        path: /mypath/*

Answer 2

https://kubernetes.github.io/ingress-nginx/user-guide/miscellaneous/#websockets

如果NGINX入口控制器提供了服务 type = LoadBalancer确保负载均衡器和 NGINX是TCP。

示例AWS L4服务https://github.com/kubernetes/ingress-nginx/blob/master/deploy/provider/aws/service-l4.yaml#L11

# Enable PROXY protocol
service.beta.kubernetes.io/aws-load-balancer-proxy-protocol: "*"

无法通过非根上下文路径中的kubernetes ingress-nginx获取Websocket应用程序的工作

2 个答案: