121 lines
3.2 KiB
Markdown
121 lines
3.2 KiB
Markdown
---
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title: Provide Load-Balanced Access to an Application in a Cluster
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content_template: templates/tutorial
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---
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{{% capture overview %}}
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This page shows how to create a Kubernetes Service object that provides
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load-balanced access to an application running in a cluster.
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{{% capture prerequisites %}}
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{{< include "task-tutorial-prereqs.md" >}} {{< version-check >}}
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* Run two instances of a Hello World application
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* Create a Service object
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* Use the Service object to access the running application
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## Creating a Service for an application running in two pods
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1. Run a Hello World application in your cluster:
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```
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kubectl run hello-world --replicas=2 --labels="run=load-balancer-example" --image=gcr.io/google-samples/node-hello:1.0 --port=8080
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```
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1. List the pods that are running the Hello World application:
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```
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kubectl get pods --selector="run=load-balancer-example"
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```
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The output is similar to this:
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```
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NAME READY STATUS RESTARTS AGE
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hello-world-2189936611-8fyp0 1/1 Running 0 6m
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hello-world-2189936611-9isq8 1/1 Running 0 6m
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```
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1. Create a Service object that exposes the deployment:
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```
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kubectl expose deployment <your-deployment-name> --type=NodePort --name=example-service
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```
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where `<your-deployment-name>` is the name of your deployment.
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1. Display the IP addresses for your service:
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```
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kubectl get services example-service
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```
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The output shows the internal IP address and the external IP address of
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your service. If the external IP address shows as `<pending>`, repeat the
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command.
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Note: If you are using Minikube, you don't get an external IP address. The
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external IP address remains in the pending state.
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NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
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example-service 10.0.0.160 <pending> 8080/TCP 40s
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1. Use your Service object to access the Hello World application:
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curl <your-external-ip-address>:8080
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where `<your-external-ip-address>` is the external IP address of your
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service.
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The output is a hello message from the application:
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Hello Kubernetes!
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Note: If you are using Minikube, enter these commands:
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kubectl cluster-info
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kubectl describe services example-service
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The output displays the IP address of your Minikube node and the NodePort
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value for your service. Then enter this command to access the Hello World
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application:
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curl <minikube-node-ip-address>:<service-node-port>
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where `<minikube-node-ip-address>` us the IP address of your Minikube node,
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and `<service-node-port>` is the NodePort value for your service.
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## Using a service configuration file
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As an alternative to using `kubectl expose`, you can use a
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[service configuration file](/docs/concepts/services-networking/service/)
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to create a Service.
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{{% capture whatsnext %}}
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Learn more about
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[connecting applications with services](/docs/concepts/services-networking/connect-applications-service/).
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