This repository consists of everything you need to setup simple Kubernetes cluster and demonstrate usage of KEDA mongo 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 4 components:

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

kubectl apply -f deployment/

Follow the official KEDA guide https://keda.sh/deploy/

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

kubectl apply -f keda/mongo-hpa.yaml

this should result again in creation of ScaleObject and an HPA:

kubectl get scaledobjects

NAME                 SCALETARGETKIND      SCALETARGETNAME   MIN   MAX   TRIGGERS   AUTHENTICATION          READY   ACTIVE   FALLBACK   PAUSED    AGE
mongo-scaledobject   apps/v1.Deployment   dummy-mongo             5     mongodb    mongodb-local-trigger   True    False    False      Unknown   1d

To scale up we have to insert some values to Mongo database. To do this we can use the helper app:

kubectl exec $(kubectl get pods | grep "server" | cut -f 1 -d " ") -- keda-talk mongo insert

to check pods being scaled:

kubectl get pods

to scale down, delete all the records:

kubectl exec $(kubectl get pods | grep "server" | cut -f 1 -d " ") -- keda-talk mongo delete

and to debug scaling of the dummy pod:

kubectl logs -n keda -l app=keda-operator