Getting familiar with Kubernetes using minikube

Overview

This post follows the Hello Minikube tutorial from official kubernetes documentation. It is a very basic starting guide and I included it here to have it as a starting point for K8s related posts.

Installation

I used Homebrew to install the required packages minikube and kubectl: brew install minikube kubectl. Both of these could be downloaded and installed using curl.

After installation, I created a minikube cluster using minikube start command. This command pulls the base minikube image using docker which creates a cluster with a control-plane node and starts a container named minikube. After the installation is complete, the created node can be accessed using kubectl get command.

kubectl get nodes
Output:
NAME       STATUS   ROLES           AGE     VERSION
minikube   Ready    control-plane   5m34s   v1.30.0

First Deployment

To run the first deployment, i ran kubectl create deployment command that runs a container based on provided image, which in this case is the kicbase/echo-server:1.0 .

kubectl create deployment hello-minikube --image=kicbase/echo-server:1.0
Output:
deployment.apps/hello-minikube created

The deployed container/s can be viewed as follows:

kubectl get deployments
Output:
NAME             READY   UP-TO-DATE   AVAILABLE   AGE
hello-minikube   1/1     1            1           10s

Similarly, the pod/s inside the container can be viewed as follows:

kubectl get pods
Output:
NAME                              READY   STATUS    RESTARTS   AGE
hello-minikube-5c898d8489-76pms   1/1     Running   0          4m57s

The pod inside the container can only be accessed from outside the kubernetes network by exposing it’s port.

First Service

A kubernetes service is required to expose it outside the virtual network which I have done as follows:

kubectl expose deployment hello-minikube --type=NodePort --port=8080
Output:
service/hello-minikube exposed

As above with deployments, the services can be viewed with the get command.

kubectl get services
Output:
NAME             TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)          AGE
hello-minikube   NodePort    10.98.7.247   <none>        8080:31513/TCP   5m28s
kubernetes       ClusterIP   10.96.0.1     <none>        443/TCP          53m

The —type=Nodeport —port=8080 flags indicates the service should be exposed in the TCP port 8080, which is the port the application inside the hello-minikube pod listens to.

Finally, I used the minikube service hello-minikube command to open the application in the browser. This command opened a browser window and showed the app response.

minikube service hello-minikube
|-----------|----------------|-------------|---------------------------|
| NAMESPACE |      NAME      | TARGET PORT |            URL            |
|-----------|----------------|-------------|---------------------------|
| default   | hello-minikube |        8080 | http://192.168.49.2:31513 |
|-----------|----------------|-------------|---------------------------|
🏃  Starting tunnel for service hello-minikube.
|-----------|----------------|-------------|------------------------|
| NAMESPACE |      NAME      | TARGET PORT |          URL           |
|-----------|----------------|-------------|------------------------|
| default   | hello-minikube |             | http://127.0.0.1:65013 |
|-----------|----------------|-------------|------------------------|
🎉  Opening service default/hello-minikube in default browser...

Additional basic commands

To remove the service: kubectl delete service hello-minikube

To remove the deployment: kubectl delete deployment hello-minikube

To stop the minikube cluster: minikube stop

To delete the minikube cluster: minikube delete