kubernetes-hands-on

Prerequisites:

• Docker
• kubernetes-cli (kubectl) : https://kubernetes.io/docs/tasks/tools/install-kubectl/
• minikube : https://minikube.sigs.k8s.io/docs/start/
• Virtualbox version 5.2+ ([or other minikube compatible hypervisors][minikube-hypervisors])

As an alternative if you are using Windows/Mac system, you can install docker desktop which provides native kubernetes support.

References:

Install K8 through Docker desktop for Windows: https://birthday.play-with-docker.com/kubernetes-docker-desktop/

Install K8 through Docker desktop for Mac: https://medium.com/backbase/kubernetes-in-local-the-easy-way-f8ef2b98be68

demo-voting-app Microservice Architecture

demo-voting-app with Pods and Services

demo-voting-app Deployment with Scale up Architecture

• A front-end web app in Python which lets you vote between two options
• A Redis queue which collects new votes
• A .NET Core worker which consumes votes and stores them in Postgres database
• A Postgres DB which store the vote count from worker
• A Node.js webapp which shows the results of the voting in real time

Run the appplication in Kubernetes

---

Clone this repo: git clone https://github.com/amrityam/kubernetes-hands-on.git

First create the demo-voting-app namespace:

kubectl create namespace demo-voting-app

Run the following command to create the deployments and services objects:

cd kubernetes-hands-on\demo-voting-app\k8-specifications

kubectl create -f deployments\voting-app-deployment.yaml
kubectl create -f services\voting-app-service.yaml

kubectl create -f deployments\redis-deployment.yaml
kubectl create -f services\redis-service.yaml

kubectl create -f deployments\postgres-deployment.yaml
kubectl create -f services\postgres-service.yaml

kubectl create -f deployments\worker-app-deployment.yaml

kubectl create -f deployments\result-app-deployment.yaml
kubectl create -f services\result-app-service.yaml

Now validate all the deployments and pods are running fine by using below command.

kubectl get deployments,pods,svc --namespace demo-voting-app

The voting-app is now available on port 30004 and the result-app one is running on port 30005.

Scale up the deployments:

kubectl scale deployments voting-app-deploy --replicas=3 --namespace demo-voting-app

Now refresh the voting-app page and you can notice each time the page is served by a new pod.

Clean up resources and delete namespace:

To stop the application and delete all resources run the below command which deletes the namespace we have created earlier.

kubectl delete namespace demo-voting-app