Ability to control verbosity of validation errors

[laszlocph]

This issue has the exact same motivation as #190

#190 was resolved by two filter function:

• kustomize-controller/controllers/kustomization_controller.go

  Line 645 in 5f966d0

  return "", fmt.Errorf("apply failed: %s", parseApplyError(output))

• kustomize-controller/controllers/kustomization_controller.go

  Line 648 in 5f966d0

  resources := parseApplyOutput(output)

and they handle the apply case perfectly.

I would like that the validate function gets the same treatment too.

kustomize-controller/controllers/kustomization_controller.go

Line 565 in 5f966d0

func (r *KustomizationReconciler) validate(ctx context.Context, kustomization kustomizev1.Kustomization, imp *KustomizeImpersonation, dirPath string) error {

There, the kustomize output is returned without any treatment:

kustomize-controller/controllers/kustomization_controller.go

Line 601 in 5f966d0

return fmt.Errorf("validation failed: %s", string(output))

resulting in a long output, where only the validation error is noteworthy:

validation failed: namespace/flux-system configured (dry run)
customresourcedefinition.apiextensions.k8s.io/alerts.notification.toolkit.fluxcd.io configured (dry run)
customresourcedefinition.apiextensions.k8s.io/buckets.source.toolkit.fluxcd.io configured (dry run)
customresourcedefinition.apiextensions.k8s.io/gitrepositories.source.toolkit.fluxcd.io configured (dry run)
customresourcedefinition.apiextensions.k8s.io/helmcharts.source.toolkit.fluxcd.io configured (dry run)
customresourcedefinition.apiextensions.k8s.io/helmreleases.helm.toolkit.fluxcd.io configured (dry run)
customresourcedefinition.apiextensions.k8s.io/helmrepositories.source.toolkit.fluxcd.io configured (dry run)
customresourcedefinition.apiextensions.k8s.io/kustomizations.kustomize.toolkit.fluxcd.io configured (dry run)
customresourcedefinition.apiextensions.k8s.io/providers.notification.toolkit.fluxcd.io configured (dry run)
customresourcedefinition.apiextensions.k8s.io/receivers.notification.toolkit.fluxcd.io configured (dry run)
serviceaccount/helm-controller configured (dry run)
serviceaccount/kustomize-controller configured (dry run)
serviceaccount/notification-controller configured (dry run)
serviceaccount/source-controller configured (dry run)
clusterrole.rbac.authorization.k8s.io/crd-controller-flux-system configured (dry run)
clusterrolebinding.rbac.authorization.k8s.io/cluster-reconciler-flux-system configured (dry run)
clusterrolebinding.rbac.authorization.k8s.io/crd-controller-flux-system configured (dry run)
secret/gitops-repo configured (dry run)
service/fosdem-2021 configured (dry run)
service/notification-controller configured (dry run)
service/source-controller configured (dry run)
service/webhook-receiver configured (dry run)
error: error validating "fffbeaa2-7f24-44ad-9db5-b14f54d552bf.yaml": error validating data: ValidationError(Deployment.spec.template.spec.containers[0]): unknown field "ima  ge" in io.k8s.api.core.v1.Container; if you choose to ignore these errors, turn validation off with --validate=false

[laszlocph]

I'm happy to take a stab at this, if the need is generally accepted by the Flux maintainers. I would repurpose the parseApplyError function and would take into account that the validation step has (dry run) suffix in each line.

[stefanprodan]

@laszlocph thanks! please go ahead