Issue with GCP PubSub scaledObject

[raghu-manne]

I am trying to test out keda with GCP pubsub andd the getting below error. Any insights where am i doing wrong?
2023-06-29T11:26:13Z ERROR Reconciler error {"controller": "scaledobject", "controllerGroup": "keda.sh", "controllerKind": "ScaledObject", "ScaledObject": {"name":"test","namespace":"default"}, "namespace": "default", "name": "test", "reconcileID": "5b54cc98-02bf-4dea-a270-125a70a957b5", "error": "HorizontalPodAutoscaler.autoscaling \"keda-hpa-test\" is invalid: spec.metrics[0].external.target.averageValue: Invalid value: resource.Quantity{i:resource.int64Amount{value:0, scale:0}, d:resource.infDecAmount{Dec:(*inf.Dec)(nil)}, s:\"0\", Format:\"DecimalSI\"}: must be positive"}
My scaledobject looks like this

apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  name: pubsub-test
  namespace: default
spec:
  scaleTargetRef:
    name: consume-pubsub-messages #Target Workload Name
  triggers:
  - type: gcp-pubsub
    authenticationRef:
      name: test
    metadata:
      subscriptionName: "keda-test-subscription" # Required

Scaledobject events says this

Events:
  Type     Reason                   Age                    From           Message
  ----     ------                   ----                   ----           -------
  Warning  ScaledObjectCheckFailed  2m6s (x16 over 4m50s)  keda-operator  failed to ensure HPA is correctly created for ScaledObject

[raghu-manne]

I am still having the same issue, i even tried with other cluster as well.
Can anyone help me here? @zroubalik @tomkerkhove @JorTurFer

[tomkerkhove]

Can you try assinging a target value please? Maybe we broke the default behavior when nothing is specified

https://keda.sh/docs/2.11/scalers/gcp-pub-sub/

[JorTurFer]

I think that the error is here:

keda/pkg/scalers/gcp_pubsub_scaler.go

Lines 73 to 96 in d48475b

	if subSize, subSizePresent := config.TriggerMetadata["subscriptionSize"]; subSizePresent {
	if modePresent || valuePresent {
	return nil, errors.New("you can use either mode and value fields or subscriptionSize field")
	}
	logger.Info("subscriptionSize field is deprecated. Use mode and value fields instead")
	subSizeValue, err := strconv.ParseFloat(subSize, 64)
	if err != nil {
	return nil, fmt.Errorf("value parsing error %w", err)
	}
	meta.value = subSizeValue
	} else {
	if modePresent {
	meta.mode = mode
	meta.value = pubSubDefaultValue
	}
	if valuePresent {
	triggerValue, err := strconv.ParseFloat(value, 64)
	if err != nil {
	return nil, fmt.Errorf("value parsing error %w", err)
	}
	meta.value = triggerValue
	}
	}

If we use the default mode, the default value isn't assigned.
And yes, this looks like a breaking change from our side because previous versions applied correctly default values.

[JorTurFer]

I think that the solution in the code is just adding the default value during meta initializtion here:

keda/pkg/scalers/gcp_pubsub_scaler.go

Lines 66 to 71 in d48475b

	func parsePubSubMetadata(config *ScalerConfig, logger logr.Logger) (*pubsubMetadata, error) {
	// set subscription size to the default mode
	meta := pubsubMetadata{mode: pubSubModeSubscriptionSize}
	mode, modePresent := config.TriggerMetadata["mode"]
	value, valuePresent := config.TriggerMetadata["value"]

Would you open a PR fixing it?

[raghu-manne]

Hi @tomkerkhove @JorTurFer,
Is this fixed now or is it still the same?
I tried it once again yesterday and i am getting the same response from the scaledObject.

[JorTurFer]

AFAIR, nobody has fixed it yet.
Are you willing to draft a PR with the fix? I think that just doing this should be enough

[raghu-manne]

@JorTurFer I don't have knowledge on Go, let me see if i can understand.