Kubernetes enables you to define a logical set of Pods and an access policy as a Service. You can then use services and service types to control how your applications receive traffic. The LoadBalancer service type creates an external load balancer in the public cloud infrastructure and assigns a fixed, external IP to the service. Users can then access the service through the exposed IP address. The application is responsible for authentication and authorization. Many public clouds allow you to restrict access to the load balancer by the source IP address. For more information, see the Kubernetes Services, Load Balancer, and Networking documentation.
This tutorial demonstrates how to expose an application running on the Konvoy cluster using the LoadBalancer (layer-4) service type.
Before you begin
Before starting this tutorial, you should verify the following:
You must have access to a Linux, macOS, or Windows computer with a supported operating system version.
You must have a properly deployed and running cluster. For information about deploying Kubernetes with default settings, see the Quick Start.
Expose a pod using the LoadBalancer (L4) service
Deploy a Redis Pod on your Kubernetes cluster by running the following command:
cat <<EOF | kubectl create -f - apiVersion: v1 kind: Pod metadata: labels: app: redis name: redis spec: containers: - name: redis image: redis:5.0.3 ports: - name: redis containerPort: 6379 protocol: TCP EOF
Create a service with the service type of LoadBalancer by running the following command:
cat <<EOF | kubectl create -f - apiVersion: v1 kind: Service metadata: labels: app: redis name: redis spec: type: LoadBalancer selector: app: redis ports: - protocol: TCP port: 6379 targetPort: 6379 EOF
The configuration settings in this example illustrate:
- setting the
- setting the
appto be exposed to
- setting the service
- setting the
Get the URL of the load balancer created by the cloud provider (AWS) for the Redis service by running the following command:
kubectl get svc redis
This command displays the internal and external IP addresses for the service.
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE redis LoadBalancer 10.0.51.32 a92b6c9216ccc11e982140acb7ee21b7-1453813785.us-west-2.elb.amazonaws.com 6379:31423/TCP 43s
Validate that you can access the Redis pod by connecting to the external IP address using the
telnet a92b6c9216ccc11e982140acb7ee21b7-1453813785.us-west-2.elb.amazonaws.com 6379 Trying 126.96.36.199... Connected to a92b6c9216ccc11e982140acb7ee21b7-1453813785.us-west-2.elb.amazonaws.com. Escape character is '^]'. quit +OK Connection closed by foreign host.