Kubernetes LoadBalancer 服务返回空响应

Question

1. node.js express 服务器绑定到端口 8080

server.listen(8080, () => {
  logger.log({
    level: 'info',
    message: 'Listening on port ' + port
  })
})

2. 带有 node.js 代码 + npm 模块的 Docker 镜像，端口 8080 暴露

FROM node:10-alpine

...

# Expose port
EXPOSE 8080

3. Kubernetes 部署 Docker 镜像并配置了 containerPort 8080

apiVersion: apps/v1

kind: Deployment

metadata:
  name: deployment

spec:
  selector:
    matchLabels:
      app: deployment

  replicas: 2

  template:
    metadata:
      labels:
        app: deployment

    spec:
      containers:
      - name: job-id-20
        image: redacted/redacted
        command: ["node", "backend/services.js"]

        ports:
        - name: http-port
          containerPort: 8080

      imagePullSecrets:
      - name: docker-hub-credentials

      dnsConfig:
        options:
          - name: ndots
            value: "0"

4. Kubernetes 服务，选择器与应用程序匹配，目标端口为 8080，类型为 LoadBalancer

apiVersion: v1

kind: Service

metadata:
  name: service

spec:
  ports:
    - protocol: TCP
      targetPort: 8080
      port: 8080

  selector:
    app: deployment

  type: LoadBalancer

5. 验证负载均衡器是否具有外部 IP（我擦洗了它）

$ kubectl --kubeconfig="k8s-1-13-4-do-0-nyc1-1552761372568-kubeconfig.yaml" get service/service
NAME      TYPE           CLUSTER-IP      EXTERNAL-IP      PORT(S)          AGE
service   LoadBalancer   10.245.239.60   1x4.2x9.1x8.x2   8080:30626/TCP   113s

6. curl 失败，响应为空

$ curl --verbose http://1x4.2x9.1x8.x2:8080/
*   Trying 1x4.2x9.1x8.x2...
* TCP_NODELAY set
* Connected to 1x4.2x9.1x8.x2 (1x4.2x9.1x8.x2) port 8080 (#0)
> GET / HTTP/1.1
> Host: 1x4.2x9.1x8.x2:8080
> User-Agent: curl/7.54.0
> Accept: */*
> 
* Empty reply from server
* Connection #0 to host 1x4.2x9.1x8.x2 left intact
curl: (52) Empty reply from server

我希望流量通过服务路由到部署中的 pods/副本之一。我究竟做错了什么？

Answer 1

检查创建映像时的任何错误，检查部署后 Pod 是否已成功部署，即它们应该处于运行状态并检查服务。如果这些条件正确，那么我几乎看不到您的步骤有任何错误。下面是一个简单的nodejs应用程序部署示例。

索引.js

var http = require('http');

var server = http.createServer(function(request, response) {

    response.writeHead(200, {"Content-Type": "text/plain"});
    response.end("Hello World!");

});

var port = 80;
server.listen(port);

console.log("Server running at http://localhost:%d", port);

泊坞窗文件：

FROM node:0.10.40
RUN mkdir -p /usr/src/app
WORKDIR /usr/src/app
COPY ./nodejs-docs-hello-world ./
RUN npm install
CMD ["node", "index.js"]

网络部署：

apiVersion: v1
kind: ReplicationController
metadata:
  labels:
    name: web
  name: web-controller
spec:
  replicas: 2
  template:
    metadata:
      labels:
        name: web
    spec:
      containers:
      - image: imagename
        name: web
        ports:
        - containerPort: 80
          name: http-server

网络服务：

apiVersion: v1
kind: Service
metadata:
  name: web
  labels:
    name: web
spec:
  type: LoadBalancer
  ports:
    - port: 80
      targetPort: 80
      protocol: TCP
  selector:
    name: web