Implement Verify Weight

[mvgmb]

Closes #22

The weight verification takes into account the following scenarios:

Valid HTTPProxy

When the HTTPProxy is valid and does not contain errors.

status:
  conditions:
  - lastTransitionTime: "2023-08-10T22:27:04Z"
    message: Valid HTTPProxy
    observedGeneration: 43
    reason: Valid
    status: "True"
    type: Valid
  currentStatus: valid
  description: Valid HTTPProxy

Invalid HTTProxy

When the HTTPProxy contains an error or its state is invalid.

status:
  conditions:
  - errors:
    - message: 'fqdn "example.com" is used in multiple
        HTTPProxies: argo-rollouts-demo/demo, test-demo/demo'
      reason: DuplicateVhost
      status: "True"
      type: VirtualHostError
    lastTransitionTime: "2023-08-10T22:26:30Z"
    message: At least one error present, see Errors for details
    observedGeneration: 1
    reason: ErrorPresent
    status: "False"
    type: Valid
  currentStatus: invalid
  description: At least one error present, see Errors for details

Outdated HTTPProxy

When the HTTPProxy status' observedGeneration field does not match the metadata's generation field don't match. This happens when the operator is unavailable or is having issues updating the HTTPProxy.

apiVersion: projectcontour.io/v1
kind: HTTPProxy
metadata:
  generation: 50
  name: demo
status:
  conditions:
  - lastTransitionTime: "2023-08-10T22:40:39Z"
    message: Valid HTTPProxy
    observedGeneration: 49 # current generation is 50, meaning the operator still hasn't reflected changes made to manifest
    reason: Valid
    status: "True"
    type: Valid
  currentStatus: valid
  description: Valid HTTPProxy

[izturn]

@mvgmb ping

[izturn]

LGTM @mvgmb thx