Prometheus as SLI provider not working

[jetzlstorfer]

Due to the current limitation that SLI providers can not live in the execution plane, there needs to be a workaround to use the data from Prometheus in this example.

One potential workaround is that the prometheus-service will subscribe to sh.keptn.event.evaluation.triggered events and sends a sh.keptn.event.get-sli.started in return. This is needed since the sh.keptn.event.get-sli.triggered can not be retrieved from services living on the execution plane.

However, this is one potential workaround, other workarounds might exist as well.
In the end, this should be supported by Keptn out-of-the-box without any workaround needed.

[jetzlstorfer]

Also referring to the KEP here keptn/enhancement-proposals#56