kubectl端口转发会忽略loadBalance服务吗? [英] Does kubectl port-forward ignore loadBalance services?

问题描述

我的环境:具有最新Minikube/Docker的Mac开发机

My Environment: Mac dev machine with latest Minikube/Docker

我使用一个简单的Django REST API"hello world"构建了一个本地的docker镜像.我正在运行一个包含3个副本的部署.这是我的yaml文件，用于对其进行定义:

I built (locally) a simple docker image with a simple Django REST API "hello world".I'm running a deployment with 3 replicas. This is my yaml file for defining it:

apiVersion: v1
kind: Service
metadata:
  name: myproj-app-service
  labels:
    app: myproj-be
spec:
  type: LoadBalancer
  ports:
    - port: 8000
  selector:
    app: myproj-be
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myproj-app-deployment
  labels:
    app: myproj-be
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myproj-be
  template:
    metadata:
      labels:
        app: myproj-be
    spec:
      containers:
        - name: myproj-app-server
          image: myproj-app-server:4
          ports:
            - containerPort: 8000
          env:
            - name: DATABASE_URL
              value: postgres://myname:@10.0.2.2:5432/myproj2
            - name: REDIS_URL
              value: redis://10.0.2.2:6379/1

当我应用此yaml时，它会正确生成东西. -一次部署 -一项服务 -三个豆荚

When I apply this yaml it generates things correctly. - one deployment - one service - three pods

部署:

NAME                  READY   UP-TO-DATE   AVAILABLE   AGE
myproj-app-deployment   3/3     3            3           79m

服务:

NAME               TYPE           CLUSTER-IP    EXTERNAL-IP   PORT(S)          AGE
kubernetes         ClusterIP      10.96.0.1     <none>        443/TCP          83m
myproj-app-service   LoadBalancer   10.96.91.44   <pending>     8000:31559/TCP   79m

豆荚:

NAME                                   READY   STATUS    RESTARTS   AGE
myproj-app-deployment-77664b5557-97wkx   1/1     Running   0          48m
myproj-app-deployment-77664b5557-ks7kf   1/1     Running   0          49m
myproj-app-deployment-77664b5557-v9889   1/1     Running   0          49m

有趣的是，当我SSH进入Minikube并使用curl 10.96.91.44:8000命中服务时，它尊重服务的LoadBalancer类型，并在我命中端点时间和时间时在所有三个Pod之间旋转再次.我可以在返回的结果中看到这一点，我确保已将Pod的HOSTNAME包括在内.

The interesting thing is that when I SSH into the Minikube, and hit the service using curl 10.96.91.44:8000 it respects the LoadBalancer type of the service and rotates between all three pods as I hit the endpoints time and again. I can see that in the returned results which I have made sure to include the HOSTNAME of the pod.

但是，当我尝试使用kubectl port-forward service/myproj-app-service 8000:8000从Hosting Mac访问服务时，每次碰到端点时，都会得到相同的Pod进行响应.它没有负载平衡.我可以很清楚地看到，当我kubectl logs -f <pod>到所有三个Pod时，只有其中一个正在处理命中，而另外两个则处于闲置状态...

However, when I try to access the service from my Hosting Mac -- using kubectl port-forward service/myproj-app-service 8000:8000 -- Every time I hit the endpoint, I get the same pod to respond. It doesn't load balance. I can see that clearly when I kubectl logs -f <pod> to all three pods and only one of them is handling the hits, as the other two are idle...

这是kubectl port-forward限制还是问题?还是我在这里错过了更大的东西?

Is this a kubectl port-forward limitation or issue? or am I missing something greater here?

推荐答案

原因是由于容器中留有Python * .pyc文件，导致我的pod随机处于崩溃状态.当Django在多容器Kubernetes部署中运行时，这会导致问题.一旦我删除了此问题，并且所有pod都成功运行，轮询便开始工作了.

The reason was that my pods were randomly in a crashing state due to Python *.pyc files that were left in the container. This causes issues when Django is running in a multi-pod Kubernetes deployment. Once I removed this issue and all pods ran successfully, the round-robin started working.

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