This post walks through running your first pods on a local Kubernetes cluster deployed via minikube. This tutorial follow the outline of the official tutorial.

Prerequisites

This tutorial assumes that you have the following programs installed:

• docker (see here)
• minikube (see here)
• kubectl (see here)

The version information for the tools used in this tutorial is as follows:

docker:

$ docker --version
Docker version 20.10.21, build baeda1f

minikube:

$ minikube version
minikube version: v1.26.0
commit: f4b412861bb746be73053c9f6d2895f12cf78565

kubectl:

$ kubectl version
Client Version: v1.24.3
Kustomize Version: v4.5.4

Create a Minikube Cluster

Start a single-node K8s cluster with minikube:

minikube start

To open the K8s dashboard provided by minikube, run:

minikube dashboard

Create a Deployment

Now that the K8s cluster is running, we can deploy a pod to the cluster with kubectl. A deployment is the preferred method for deploying and managing the lifecycle of pods. For this pod, we use a container image provided by the K8s organization (registry.k8s.io/e2e-test-images/agnhost:2.39). Once deployed to the cluster, the single-container pod implements a simple web service.

Deploy the pod to the cluster with kubectl:

kubectl create deployment hello-node --image=registry.k8s.io/e2e-test-images/agnhost:2.39 -- /agnhost netexec --http-port=8080

We can now use kubectl to query information about our deployment / pod:

# View the deployment
NAME         READY   UP-TO-DATE   AVAILABLE   AGE
hello-node   1/1     1            1           40s
# View the pod
NAME                          READY   STATUS    RESTARTS   AGE
hello-node-667997dc6c-fqvrl   1/1     Running   0          44s

This information is also available in the web-based dashboard provided by minikube.

Create a Service

Now we have a pod running in the cluster, but we have no way of interacting with the web service that it implements. In order to expose the web service to requests from outside the K8s virtual network, we need a service.

Expose the port on which the webserver runs with kubectl:

kubectl expose deployment hello-node --type=LoadBalancer --port=8080

Under the hood, the kubectl expose command creates a service that exposes the webserver port outside of the cluster. We can check the service that was created with:

kubectl get services

At this point, if our cluster were not deployed with minikube, an external IP address would be allocated and our webservice would be accessible there. With minikube, we have to user the minikube service command to access the newly exposed service:

minikube service hello-node

Cleanup

Cleanup our service and deployment with:

kubectl delete service hello-node
kubectl delete deployment hello-node

References

• Kubernetes Official: Hello Minikube
• minikube Documentation
• kubectl Documentation
• docker Documentation