Is there a way to pass environment variables through the services in Kubernetes?

I tried passing it in to my service yaml like this:

apiVersion: v1
kind: Service
metadata:
  labels:
    name: kafka
  name: kafka
spec:
  ports:
    - port: 9092
    selector:
      name: kafka
  env:
    - name: BROKER_ID
      value: "1"

The service is being consumed by kubectl, and is created.

I've confirmed the service is connected to my container through env | grep KAFKA and the output of variables greatly increase, as expected when my service is up.

However, I would like to pass in custom environment-variables that have to be different depending on which instance of the container it is in.

Is this possible?