Resolve TriggerBindings with no Kind set in sink

[dibyom]

Changes

When upgrading from 0.2.1 to 0.3, the Sink might have
to process a Binding that has no Kind set. This is
because, we only persist the default Kind when the Binding
object is created/updated. The reconciler also sets the defaults
by calling SetDefaults but that change is not persisted to etcd.

In the future, we might want to consider updating the object from the
reconciler itself if any default values were set.

Fixes: #459

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[ncskier]

/test pull-tekton-triggers-build-tests

[ncskier]

This might be a problem if a user does not add the kind field for their bindings, and then tries to update the EventListener, right? https://github.com/tektoncd/triggers/blob/master/pkg/apis/triggers/v1alpha1/event_listener_validation.go#L53

if b.Kind != NamespacedTriggerBindingKind && b.Kind != ClusterTriggerBindingKind {
	return apis.ErrInvalidValue(fmt.Errorf("invalid kind"), fmt.Sprintf("bindings[%d].kind", i))
}

[dibyom]

This might be a problem if a user does not add the kind field for their bindings, and then tries to update the EventListener, right? https://github.com/tektoncd/triggers/blob/master/pkg/apis/triggers/v1alpha1/event_listener_validation.go#L53

I don't think so. For any newly created/updated bindings, we'll set the right defaults so that validation branch should never be hit. The issue is only for old bindings that are not updated.

[dibyom]

Also, the build failures are real, still testing this out :D

[akihikokuroda]

/approve

[ncskier]

I tested this out and was able to upgrade from v0.2.1 without any problems 👍
/lgtm

[tekton-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: akihikokuroda, ncskier

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