This repository consists of everything you need to setup simple Kubernetes cluster and demonstrate usage of KEDA redis and cron scalers. For more samples check https://github.com/kedacore/samples

The included helper provides an easy way to perform both 0 -> n and n -> 0 scalings.

The deployment consists of 3 components:

• Redis instance
• Dummy pod that will be scaled up and down
• App service that provides some helper methods

./scripts/build.sh

kind create cluster

./scripts/kind-load.sh

kubectl apply -f deployment/

Deploying KEDA with Helm is very simple:

• Add Helm repo: helm repo add kedacore https://kedacore.github.io/charts
• Update Helm repo: helm repo update
• Install keda Helm chart

kubectl create namespace keda
helm install keda kedacore/keda --namespace keda

To observe how everything works you can watch two things:

• number of pods and their state: watch -n2 "kubectl get pods"
• HPA stats: watch -n2 "kubectl get hpa"

To scale the server deployment using Cron scaler first we have to deploy the ScaledObjects:

kubectl apply -f keda/cron-hpa.yaml

this should result in creation of a new ScaledObjects and new HPA.

Scale will be performed down on odd minutes add restored to default replica on even minutes.

To scale the dummy deployment using Redis scaler first we have to deploy the ScaledObjects:

kubectl apply -f keda/redis-hpa.yaml

this should result in creation of a new ScaledObjects and new HPA

# kubectl get scaledobjects
NAME                 DEPLOYMENT   TRIGGERS   AGE
redis-scaledobject   dummy        redis      5s

# kubectl get hpa
NAME             REFERENCE          TARGETS              MINPODS   MAXPODS   REPLICAS   AGE
keda-hpa-dummy   Deployment/dummy   <unknown>/10 (avg)   1         4         0          45s

To scale up we have to populate the Redis queue. To do this we can use the helper app:

kubectl exec -it $(k get pods | grep "server" | cut -f 1 -d " ") /go/bin/keda-talk redis publish

and to scale down:

kubectl exec -it $(k get pods | grep "server" | cut -f 1 -d " ") /go/bin/keda-talk redis drain