Current behavior

• When updating a method and the reference of the method in a mapping rule in the Backend CR the following error is shown:

  Error sync backend [backend-name] mappingrules: backend metric method ref for mapping rule not found
  

• When updating a method and the reference of the method in a  mapping rule in the Product CR the following error is shown:

  Error sync product [product-name] mappingrules: product metric method ref for mapping rule not found
  

 Steps to reproduce:
1) Create a Backend with a couple of mapping rules
2) Create a Product which has the Backend referenced
3) Promote the Product
4) Delete the existing mapping rules and methods and put new ones in the Backend CR at the same time (as one operation). The Backend CR will not sync and will show the error: "'Task failed SyncMappingRules: Error sync backend [backend-reproducer] mappingrules: backend metric method ref for mapping rule not found'"
5) OR instead of step 4), update the method and the reference of the method in the mapping rule at the same time. For example:

Initial mapping rules:

  mappingRules:
    - httpMethod: GET
      increment: 1
      last: false
      metricMethodRef: GET_one
      pattern: /one
    - httpMethod: POST
      increment: 1
      last: false
      metricMethodRef: POST_one
      pattern: /one
  methods:
    GET_one:
      friendlyName: GET /one
    POST_one:
      friendlyName: POST /one
 

Change applied:

  mappingRules:
    - httpMethod: GET
      increment: 1
      last: false
      metricMethodRef: GET_two ----> method udpated
      pattern: /one
    - httpMethod: POST
      increment: 1
      last: false
      metricMethodRef: POST_one
      pattern: /one
  methods:
    GET_two:
      friendlyName: GET /two  ----> method udpated
    POST_one:
      friendlyName: POST /one

 
Currently the 3scale Operator cannot delete a method that is referenced by at least one mapping rule from an active gateway configuration. The solution to the issue is shared in this KCS solution:

1. Create new methods and/or metrics
2. Update the mapping rules to use those methods/metrics and/or create new mapping rules
3. Promote the Product
4. Delete the methods and mapping rules not in use
5. Promote the Product

Expected behavior
It should be possible updating any methods and references of the methods in mapping rules at once either in a Product CR or Backend CR.