无法从 K8s 集群访问节点应用程序

Question

I have deployed a very simple node application to a minikube cluster. I created the docker image and everything is working fine while in the container. When I build it in the k8s cluster, I can see the deployment is working.

I am trying to access the node application through a load balancer using the minikube IP and port provided when running "kubectl get svc". I know I'm doing this part correct at least...

When I try to access the URL and check the network tab, the request never finishes and just stays pending.

The node app is a very simple API I made just for testing so I use the route /posts when trying to access the application. It should return some JSON and this all works from the container. It all just stops working while in the cluster.

apiVersion: apps/v1
kind: Deployment
metadata: 
  name: server-deployment
spec: 
  replicas: 3
  selector: 
    matchLabels: 
      targets: nodes
  template: 
    metadata: 
      labels: 
        targets: nodes
    spec: 
      containers: 
        - name: server
          image: brandonjones085/mean-backend
          ports: 
            - containerPort: 3000

---
apiVersion: v1
kind: Service
metadata:
  name: backend-load
spec:
  selector:
  
    targets: nodes
  ports:
  - protocol: "TCP"
    port: 3000
    targetPort: 3000
  type: LoadBalancer

Answer 1

Just like @Hackerman described, if you using the LoadBalancer type of service you need to use minikube tunnel . You can follow the example . This type of service is usually meant to provision a provider Load Balancer, for example, an AWS ELB . But in the case of minikube there is no external provider and you need to trick it into thinking there is one.

Basically, you need to run it before you create your Deployment.

On a separate terminal:

minikube tunnel

Then apply your manifest YAML file that includes your definition in your question:

kubectl apply -f <your-deployment>.yaml

✌️

Answer 2

In addition to @Rico answer: there are two ways to access applications deployed on minikube.

First - using NodePort . When exposing application using NodePort service type you are able to access it by executing minikube service list and accessing URL shown by the output- it is result of minikube ip and nodeport. Output will be similar to this:

|-------------|------------|----------------------------|-----|
|  NAMESPACE  |    NAME    |        TARGET PORT         | URL |
|-------------|------------|----------------------------|-----|
|             |
| default     | nginx      | http://192.168.39.22:30345 |
|             |
|-------------|------------|----------------------------|-----|

Second option is by using minikube tunnel command. It assigns externalIP to application exposed by LoadBalancer service type. When trying to access it minikube tunnel has to be running and in separate terminal you can access it using externalIP:port . Example output of minikube tunnel :

$minikube tunnel
Status:
        machine: minikube
        pid: 9284
        route: 10.96.0.0/12 -> 192.168.39.22
        minikube: Running
        services: [backend-load]

Then you can check external IP assigned to this service by running kubectl get service :

kubectl get svc
NAME           TYPE           CLUSTER-IP       EXTERNAL-IP      PORT(S)          AGE
backend-load   LoadBalancer   10.100.120.115   10.100.120.115   3000:31676/TCP   110s

so in this example application will be accessible under 10.100.120.115:3000 .