(bugfix) Issue-1464 issue resolved

[S-mishina]

summary

if delegation: true is set while a VirtualService has already been created by Flagger, there are no changes to the newSpec. Therefore, I suspect that the hosts and gateway are not removed.

flagger/pkg/router/istio.go

Lines 296 to 300 in 9a0c6e7

	if canary.Spec.Service.Delegation {
	// delegate VirtualService requires the hosts and gateway empty.
	virtualService.Spec.Gateways = []string{}
	virtualService.Spec.Hosts = []string{}
	}

flagger/pkg/router/istio.go

Line 333 in 9a0c6e7

if specDiff != "" || labelsDiff != "" || annotationsDiff != "" {

[MEMO] Code of the relevant part

flagger/pkg/router/istio.go

Lines 325 to 364 in 9a0c6e7

	if virtualService != nil {
	specDiff := cmp.Diff(
	newSpec,
	virtualService.Spec,
	ignoreCmpOptions...,
	)
	labelsDiff := cmp.Diff(newMetadata.Labels, virtualService.Labels, cmpopts.EquateEmpty())
	annotationsDiff := cmp.Diff(newMetadata.Annotations, virtualService.Annotations, cmpopts.EquateEmpty())
	if specDiff != "" || labelsDiff != "" || annotationsDiff != "" {
	vtClone := virtualService.DeepCopy()
	vtClone.Spec = newSpec
	vtClone.ObjectMeta.Annotations = newMetadata.Annotations
	vtClone.ObjectMeta.Labels = newMetadata.Labels
	//If annotation kubectl.kubernetes.io/last-applied-configuration is present no need to duplicate
	//serialization. If not present store the serialized object in annotation
	//flagger.kubernetes.app/original-configuration
	if _, ok := vtClone.Annotations[kubectlAnnotation]; !ok && specDiff != "" {
	b, err := json.Marshal(virtualService.Spec)
	if err != nil {
	ir.logger.Warnf("Unable to marshal VS %s for orig-configuration annotation", virtualService.Name)
	}
	if vtClone.ObjectMeta.Annotations == nil {
	vtClone.ObjectMeta.Annotations = make(map[string]string)
	} else {
	vtClone.ObjectMeta.Annotations = filterMetadata(vtClone.ObjectMeta.Annotations)
	}
	vtClone.ObjectMeta.Annotations[configAnnotation] = string(b)
	}
	_, err = ir.istioClient.NetworkingV1beta1().VirtualServices(canary.Namespace).Update(context.TODO(), vtClone, metav1.UpdateOptions{})
	if err != nil {
	return fmt.Errorf("VirtualService %s.%s update error: %w", apexName, canary.Namespace, err)
	}
	ir.logger.With("canary", fmt.Sprintf("%s.%s", canary.Name, canary.Namespace)).
	Infof("VirtualService %s.%s updated", virtualService.GetName(), canary.Namespace)
	}
	}

※ This is just a suggestion for now, and there may be a better way to do it.

reference)
#1464

[S-mishina]

The current fix causes the changes to be periodically applied to Istio. It would be better to incorporate newSpec and detect the differences, so that only the changes are applied.

80cae71

[S-mishina]

flagger/pkg/router/istio.go

Lines 296 to 300 in 9a0c6e7

	if canary.Spec.Service.Delegation {
	// delegate VirtualService requires the hosts and gateway empty.
	virtualService.Spec.Gateways = []string{}
	virtualService.Spec.Hosts = []string{}
	}

If we replace the above with newSpec and make a difference, it could be applied!

65867f7

[S-mishina]

If virtualService.Spec.Gateways and virtualService.Spec.Hosts are empty, wouldn't it mean that no differences will be detected if nothing is added to newSpec?

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 6 lines in your changes are missing coverage. Please review.

Project coverage is 34.09%. Comparing base (e3a529e) to head (808f945).
Report is 18 commits behind head on main.

Files	Patch %	Lines
pkg/router/istio.go	0.00%	6 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #1644       +/-   ##
===========================================
- Coverage   56.51%   34.09%   -22.43%     
===========================================
  Files          85      282      +197     
  Lines        8571    20563    +11992     
===========================================
+ Hits         4844     7011     +2167     
- Misses       3053    12622     +9569     
- Partials      674      930      +256     

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