部署期间 GKE 超时和 502 上的 kubernetes 入口

Question

我很难弄清楚为什么 GKE 上的入口在项目部署期间返回 502 错误和超时。

为了更好地理解这个问题，我设置了一个基本的hello application，它采用相同的工作流程。

这是完整的清单：

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: helloapp
  labels:
    app: helloapp
spec:
  replicas: 3
  template:
    metadata:
      labels:
        app: helloapp
    spec:
      containers:
      - name: helloapp
        image: gcr.io/${GCLOUD_PROJECT_ID}/helloapp:${HELLOAPP_VERSION}
        imagePullPolicy: Always
        ports:
        - name: http-server
          containerPort: 8080

        readinessProbe:
          httpGet:
            path: /sys/health
            port: 8080

        livenessProbe:
          httpGet:
            path: /sys/health
            port: 8080

---

apiVersion: v1
kind: Service
metadata:
  name: helloapp
  labels:
    app: helloapp
spec:
  type: NodePort
  externalTrafficPolicy: Local
  ports:
    - port: 80
      targetPort: http-server
  selector:
    app: helloapp

---

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: helloapp-http
spec:
  backend:
    serviceName: helloapp
    servicePort: 80

其中包含一个入口、一个服务和为 pod 定制的探针。

该应用程序是用Go 编写的简单的hello world 应用程序。

在部署期间，如果我围攻我的应用程序的入口运行状况检查并且我注意到：

HTTP/1.1 502     9.02 secs:     332 bytes ==> GET  /sys/health
HTTP/1.1 502     9.10 secs:     332 bytes ==> GET  /sys/health
HTTP/1.1 200     4.70 secs:     473 bytes ==> GET  /sys/health
HTTP/1.1 200     4.56 secs:     475 bytes ==> GET  /sys/health
HTTP/1.1 200     0.01 secs:     475 bytes ==> GET  /sys/health
HTTP/1.1 200     0.01 secs:     476 bytes ==> GET  /sys/health
HTTP/1.1 200     0.03 secs:     475 bytes ==> GET  /sys/health
HTTP/1.1 200     0.01 secs:     474 bytes ==> GET  /sys/health
HTTP/1.1 200     4.58 secs:     475 bytes ==> GET  /sys/health
HTTP/1.1 200     4.51 secs:     474 bytes ==> GET  /sys/health
HTTP/1.1 200     0.01 secs:     475 bytes ==> GET  /sys/health
HTTP/1.1 200     0.01 secs:     475 bytes ==> GET  /sys/health
HTTP/1.1 200     4.83 secs:     474 bytes ==> GET  /sys/health
HTTP/1.1 502     9.07 secs:     332 bytes ==> GET  /sys/health
HTTP/1.1 200     0.02 secs:     475 bytes ==> GET  /sys/health

几分钟后（一般是 5-10 分钟），它会停止并正确转发请求。

集群信息：

• Kubernetes 版本：1.8.8
• 谷歌云平台
• g1-小

Answer 1

您的配置一切正常。看起来您在启动 go-app 期间遇到了问题：对您的服务进行轮询正在向 pod 中未启动的应用发送一些请求，这会导致代码 502 出错。

您的应用在 pod 中启动多长时间？您可以添加initialDelaySeconds 来修复您的错误。

spec:
  replicas: 3
  template:
    metadata:
      labels:
        app: helloapp
    spec:
      containers:
      - name: helloapp
        image: gcr.io/${GCLOUD_PROJECT_ID}/helloapp:${HELLOAPP_VERSION}
        imagePullPolicy: Always
        ports:
        - name: http-server
          containerPort: 8080

        readinessProbe:
          httpGet:
            path: /sys/health
            port: 8080
            initialDelaySeconds: 60

        livenessProbe:
          httpGet:
            path: /sys/health
            port: 8080
            initialDelaySeconds: 120