Osmclient changes related to VIM configuration with a Prometheus TSDB system

Proposers

• Luis Vega(Whitestack)

Description

After the changes introduced in feature 10920, we need to enhance the feature. For that, we will add a default metric mapping for prometheus case and change how the prometheus_config.json file works. Also, the user could map some of the metric (not all of them). Other change that will be added is the Robot Test for VIM that uses Prometheus as Telemetry System. Finally, we have to document the functionality.

Demo or definition of done

Adding a VIM that does not have Gnocchi but a Prometheus TSDB for storing VM metrics, should allow for the same functionality that OSM has today with Gnocchi collection, including the storage of those metrics in OSM's Prometheus under the same names, as well as the autoscaling and other capabilities. Be able to create say VIM with the prometheus_config.json file, just with some mappings or without anyone and get the same functionality.