Given that we want to extend the metrics available through the Metrics API, and that Kubernetes allows us that through it's Custom Metrics API (https://github.com/kubernetes/metrics/tree/master/pkg/apis/custom_metrics), one option to accomplish our goals could be to create our own adapter.
Depending on the application (DB) where we store metrics, that might be a good option. But, given that it is pointless to reinvent the wheel, our first step should be to search for a solution. If someone already created an adapter that suits our needs, it would make sense to adopt it, instead of creating a new one by ourselves. Even if we do choose something that provides only part of the features we're looking for, it's easier ...
