Bootstrap SLO controller

[thisthat]

Goal

Extend the Keptn Operator with a controller for SLO CRDs.

Technical Details

The Controller should monitor SLO in a format compatible with the current Keptn SLO format.
The SLO format should be part of the spec field.

Example

apiVersion: lifecycle.keptn.sh/v1alpha1
kind: SLO
metadata:
  name: service-test
spec:
  comparison:
    aggregate_function: "avg"
    compare_with: "single_result"
    include_result_with_score: "pass"
    number_of_comparison_results: 1
  filter:
  objectives:
    - sli: "response_time_p95"
      displayName: "Response time P95"
      key_sli: false
      pass:             # pass if (relative change <= 10% AND absolute value is < 600ms)
        - criteria:
            - "<=+10%"  # relative values require a prefixed sign (plus or minus)
            - "<600"    # absolute values only require a logical operator
      warning:          # if the response time is below 800ms, the result should be a warning
        - criteria:
            - "<=800"
      weight: 1
  total_score:
    pass: "90%"
    warning: "75%"

Acceptance Criteria

• The operator monitors Keptn SLO

[oleg-nenashev]

IMHO it should be rather Keptn Lighthouse in the final implementation: keptn/keptn#8985 . And whatever works for the demo. How much of the Keptn codebase do you plan to use @thisthat @odubajDT ? Would it be a hardfork for now?

[thisthat]

@oleg-nenashev this ticket will be closed. I had a discussion with @thschue about how to structure the whole evaluation.
I will create the tickets for this ASAP and let you know :)

[thisthat]

Closing in favor of #122