I have 2 services. Service A and Service B. They correspond to deployments dA and dB.

I set up my cluster and start both services/deployments. Service A is reachable from the external world. External World --> Service A <--> Service B.

How can I scale dB (change replicaCount and run kubectl apply OR kubectl scale) from within Service A that is responding to a user request.

For example, if a user that is being served by Service A wants some extra resource in my app, I would like to provide that by adding an extra pod to dB. How do I do this programatically?