NextJS & Kubernetes

General instructions

Run docker-compose firest. This will build and tag the nextjs image (also useful for quickly testing the image was build and runs) and starts a local Docker Registry. This local DOcker registry will be used from our Local Kubernetes. Using a local DOcker registry is faster both in downloading and most importantly uploading the built image.

docker-compose up -d
docker tag nextjs-k8s 192.168.1.4:5000/nextjs-k8s
docker push 192.168.1.4:5000/nextjs-k8s

For more convenience I have tagged this image as karadalex/nextjs-k8s and pushed it at the public Docker hub (this is a slow operation).

Deploy to Kubernetes

cd k8s
./kube-up.sh

Quickly test nextjs via port-forwarding

kubectl port-forward service/nextjs-k8s 3000

and visit the Nextjs app at http://localhost:3000

Autoscaling

Install metrics server (with insecure flag passed, do not use in production) to use cpu metrics for the autoscaling

kubectl apply -f metrics-server.yaml

Set autoscaling strategy

cd k8s
kubectl autoscale deployment nextjs-k8s --cpu-percent=50 --min=2 --max=10

Simulate load

kubectl run -i --tty load-generator --image=busybox /bin/sh
while true; do wget -q -O- http://nextjs-k8s:3000; done

Scale down

kubectl scale deploy nextjs-k8s --replicas=2
kubectl get pods -w

For more complex load scenarios install k6 https://k6.io/docs/getting-started/installation/ start the port-forwarding

kubectl port-forward service/nextjs-k8s 3000

and then run the load test

k6 run load-test-autoscaling.js