I have a set of applications which are being monitored by Prometheus. Below are sample time series of the metrics:

fastapi_responses_total{app_name="orion-gen-proj_managed-cus-test-1_checkout-api", job="app-b", method="GET", path="/metrics", status_code="200"}
        
fastapi_responses_total{app_name="orion-gen-proj_managed-cus-test-1_registration-api", job="app-a", method="GET", path="/metrics", status_code="200"

These metrics are captured from two different applications. The application names are represented by the substrings checkout-api and registration-api . The applications run on an organisation entity and this entity is represented by the substring managed-cus-test-1. The name of the organisation that an application belongs to always starts with the string managed- but can it have any wildcard value after the string “managed-” e.g managed-cus-test-1 , managed-cus-test-2, managed-cus-test-3

To calculate the availability SLO for these applications I have prepared the following set of recording rules:

groups:
- name: registration-availability
  rules:
  - record: slo:sli_error:ratio_rate5m
    expr: |-
     (avg_over_time( ( (
        (sum(rate(
          fastapi_responses_total{
            app_name=~".*registration-api.*",
            status_code!~"5.."}[5m]
          )) 
        )
        / on(app_name) group_right()
        (sum(rate(
          fastapi_responses_total{
            app_name=~".*registration-api.*"}[5m])
          ))
      ) OR on() vector(0))[5m:60s])
      )
    labels:
      slo_id: registration-availability
      slo_service: registration
      slo: availability

- name: checkout-availability
  rules:
  - record: slo:sli_error:ratio_rate5m
    expr: |-
(avg_over_time( ( (
        (sum(rate(
          fastapi_responses_total{
            app_name=~".*checkout-api.*",
            status_code!~"5.."}[5m]
          )) 
        )
        / on(app_name) group_right()
        (sum(rate(
          fastapi_responses_total{
            app_name=~".*checkout-api.*"}[5m])
          ))
      ) OR on() vector(0))[5m:60s])
      )
        labels:
          slo_id: checkout-availability
          slo_service: checkout
          slo: availability

The recording rules are evaluating correctly and they return two different SLO values, one for each of the applications. I have a requirement to calculate the overall SLO of these two applications. This overall SLO should be based on the organisation to which an application belongs.

For example, because the applications checkout-api and registration-api belong to the same organisation, the SLO calculation should return one consolidated value.

What I want is a label_replace that adds a new label “org” and then does grouping by “org”.

The label_replace should add the new label and preserve the existing filter based on app_name, not replace it.