Kubernetes Hands-on Workshop

6 min readDec 24, 2021

Kubernetes is used to maintain, scale and deploy containerised applications. It is one of the most used open-source application that accelerate the application lifecycle. In this blog, I am going to teach Kubernetes via a hands-on workshop. The contents of the workshop;

Install Minikube
Kubernetes common features
Run a pod
Run the cron job
Create a secret
Kubernetes logs
Create config map
Create a pod with json
Create service
Kubernetes service types
Create load balancer
Nodeport example
Creating Kubernetes Deployment
Update the image for deployment
e2e application via Kubernetes
Create Kubernetes cluster on AWS

Install minikube (Docker)

The workshop will be done on minikube, you can also use any Kubernetes cloud provider like AWS, Azure, Google..

https://minikube.sigs.k8s.io/docs/start/

Step 1 — Start cluster using Docker

Start a cluster using the docker driver:

minikube start — driver=docker

Step 2 — Start minikube

minikube start

Step 3 — Test sample command

kubectl get pod

Run a pod

A pod consist of multiple application that can be deployed to Kubernetes

Step 1 — Run the pod with the following command

kubectl run nginx — image=nginx

First parameter is pod name
Second parameter is the image name

Step 2 — List the pod

kubectl get pod

Create namespace

It allow to separate the containerised applications through different virtual clusters

kubectl create ns nginx-ns

Run a pod via file definition

Prepare the pod with the following definition

As a first step, you need to create a namespace

kubectl create ns nginx-ns

Create a pod with the required specifications

kubectl apply -f pod.yaml

You can check whether the pod is running in the nginx-ns namespace

kubectl get pod --namespace=nginx-ns

Create a cron job

Let’s create a cron job with the following specifications

name of job : cron
time interval : every 5 minutes
container name : busyboxcron
image: busybox

The container is supposed to print the date in the system shell

Tip : When you see this kind of question, please search cron job in the documentation

Create the cronjob with the following yaml

You can check the pod

kubectl get pods

Create a pod with secret

Create a secret with the following command

kubectl create secret generic db-secret — from-literal=username=serkan — from-literal=password=serkan123

Let’s create a pod with the following specifications

secret name= db-secret
readonly = true
pod name = mypod
container name = redis
image = redis
mountPath = “/etc/foo”

kubectl apply -f pod_secret.yaml

Connect to the pod

kubectl exec mypod -it sh

Locate to the folder

cd /etc/foo

List the files

ls -l

Create a config map

Create a config map with the following command

kubectl create configmap myconfig — from-literal=dbType=DynamoDB — from-literal=progLanguage=Java

Create a POD with the following features, use the myconfig as a ConfigMap.

pod name : podconfig
container name : busybox
image : k8s.gcr.io/busybox

Define the following e pod environment variables from myconfig

DATABASE_TYPE from dbType
PROGRAMMING_LANGUAGE from progLanguage

Use the following pod definition

Create the pod with the following command

Create a service

Please create the following pod before starting to the question

Create a Service that expose the pod on port 443. The name of the service should be myservice

Expose the pod via following command

kubectl expose pod static-web --port=443 —-name=myservice

You can check via kubectl get services command

Create a service ( NodePort)

Please run the pod before starting to the exercise

kubectl run nginx — image=nginx

Create a service for nginx pod which serves on port 80 and the type should be NodePort. The service name should be nginx-service

Expose the pod with kubectl command

kubectl expose pod nginx --port=80 --type=NodePort --name=nginx-service

You can check whether the service is created

kubectl get service nginx-service

Kubernetes Deployment

Please see the sample configuration for deployment

kubectl apply -f deployment.yaml

Kubernetes Deployment ( Update max.unavailable )

Please deploy the following deployment for that exercise

Deploy the provided yaml in the question

kubectl apply -f deployment.yaml

In the nginx-deployment, please make a required configuration that specifies the maximum 2 Pods that can be unavailable during the update process.

.spec.strategy.rollingUpdate.maxUnavailable is an optional field that specifies the maximum number of Pods that can be unavailable during the update process. !!!!

In order to make an update in the deployment, execute this comment

kubectl edit deployment nginx-deployment

Max Unavailable

.spec.strategy.rollingUpdate.maxUnavailable is an optional field that specifies the maximum number of Pods that can be unavailable during the update process. The value can be an absolute number (for example, 5) or a percentage of desired Pods (for example, 10%).

Change the .spec.strategy.rollingUpdate.maxUnavailable field in the deployment

As-is

to-be

After the change, save the file, You should see the file is edited

Kubernetes Deployment rollback

Please deploy the following deployment for that exercise

For the nginx-deployment , please update image with nginx:1.16.1 version. After the rollout is successfully finished, please rollout undo the image with previous version

As a first step, please create the deployment in Kubernetes