scale-in-cluster

in-cluster-scaler

A simple pod scaler golang application that can scale pod replicas inside the cluster via manipulating the deployment

Setup & Installtion

git clone <repo-url>

For acquiring the Docker image either pull the image or build a new image using Dockerfile via type this command:

docker build -t <image-name> .

⚠️ If you will use the newly created Docker image, you need to change the image property of the deployment manifest with the new <image-name>.

Ingress part:

In order to access the services from outside the cluster, we need to install Ingress Controller then create an ingress manifest. It allows us to reach services via a browser by just typing a URL and it also maps custom DNS names to IP addresses.

Install NGINX Ingress Controller for Docker Desktop from here

To use custom DNS name to reach application via browser, we need to edit hosts, append 127.0.0.1 podmanagement.com to hosts by using this command:

sudo nano /etc/hosts

Running The App

To run the application, we need to create deployment and ingress from yaml files using these commands:

kubectl apply -f pod-scaler.deployment.yaml
kubectl apply -f pod-scaler.ingress.yaml

⚠️ There should exist a dummy pod that crated with deployment manifest inside the cluster. I used this repository to create a pod that used a deployment named nodeapp-deployment

Open a browser and then go to podmanagement.com to make sure that application is running

podmanagement.com/scale/{replica-count} to scale the specific replicas

Getting basic info about kubernetes components:

kubectl get node
kubectl get pod
kubectl get service
kubectl get ingress
kubectl get all