website/content/en/docs/tasks/access-application-cluster/load-balance-access-applica...

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Provide Load-Balanced Access to an Application in a Cluster templates/tutorial

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This page shows how to create a Kubernetes Service object that provides load-balanced access to an application running in a cluster.

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  • Run two instances of a Hello World application
  • Create a Service object
  • Use the Service object to access the running application

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Creating a Service for an application running in two pods

  1. Run a Hello World application in your cluster:

    ```
    kubectl run hello-world --replicas=2 --labels="run=load-balancer-example" --image=gcr.io/google-samples/node-hello:1.0  --port=8080
    ```
    
  2. List the pods that are running the Hello World application:

    ```
    kubectl get pods --selector="run=load-balancer-example"
    ```
    

    The output is similar to this:

    ```
    NAME                           READY     STATUS    RESTARTS   AGE
    hello-world-2189936611-8fyp0   1/1       Running   0          6m
    hello-world-2189936611-9isq8   1/1       Running   0          6m
    ```
    
  3. Create a Service object that exposes the deployment:

    ```
    kubectl expose deployment <your-deployment-name> --type=NodePort --name=example-service
    ```
    

    where <your-deployment-name> is the name of your deployment.

  4. Display the IP addresses for your service:

    ```
    kubectl get services example-service
    ```
    

    The output shows the internal IP address and the external IP address of your service. If the external IP address shows as <pending>, repeat the command.

    Note: If you are using Minikube, you don't get an external IP address. The external IP address remains in the pending state.

    NAME              CLUSTER-IP   EXTERNAL-IP   PORT(S)    AGE
    example-service   10.0.0.160   <pending>     8080/TCP   40s
    
  5. Use your Service object to access the Hello World application:

    curl <your-external-ip-address>:8080
    

    where <your-external-ip-address> is the external IP address of your service.

    The output is a hello message from the application:

    Hello Kubernetes!
    

    Note: If you are using Minikube, enter these commands:

    kubectl cluster-info
    kubectl describe services example-service
    

    The output displays the IP address of your Minikube node and the NodePort value for your service. Then enter this command to access the Hello World application:

    curl <minikube-node-ip-address>:<service-node-port>
    

    where <minikube-node-ip-address> us the IP address of your Minikube node, and <service-node-port> is the NodePort value for your service.

Using a service configuration file

As an alternative to using kubectl expose, you can use a service configuration file to create a Service.

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Learn more about connecting applications with services. {{% /capture %}}