After some readings, it seems there is no sustainable solution for auto-scaling Redis on Kubernetes without adding a controller like Maestro. Unfortunatly the project seems a bit dead.
What are some alternatives for autoscaling Redis ?
Edit: Redis is a statefull app.
If you want to autoscale anything on Kubernetes, it requires some type of controller. For general autoscaling, the community is rallying around the Horizontal Pod Autoscaler. By default, you configure it to scale based on CPU utilization.
If you want to scale based on metrics other than CPU utilization and you're using the Redis helm chart, you can easily configure it to run a Prometheus metric sidecar and can set the autoscaler to scale based on one of those values.