As a JDG Admin I can monitor a JDG cluster using Prometheus
So that system metrics can be monitored (For example, most of the JMX metrics, JVM settings and cache related aspect should be exposed.)
and alerts can be triggered based on thresholds for such metrics.

Acceptance Criteria:
Prometheus server can collect metrics from a JDG cluster.
Endpoints should be accessible (query) through REST (curl).

Background: Prometheus the current monitoring and alert standard for Cloud Native Foundation and the default choice for monitoring Kubernetes applications. As we integrate JDG (full) and JDG based services on OpenShift, we should enable Prometheus endpoints on JDG in order to enable monitoring using this tool. There is an on-going discussion about CloudForms and Prometheus on the OpenShift side but even if CloudForms become the standard they will work on a connector to read Prometheus endpoints to provide an integrated monitoring solution.