Scope operator interaction to namespace

[Zerpet]

Looking at the RabbitmqClusterReference property in User kind:

messaging-topology-operator/api/v1alpha1/user_types.go

Lines 18 to 33 in 06637f5

	type UserSpec struct {
	// Username of the user to create on a RabbitmqCluster.
	// +kubebuilder:validation:Required
	Name string `json:"name"`
	// List of permissions tags to associate with the user. This determines the level of
	// access to the RabbitMQ management UI granted to the user. Omitting this field will
	// lead to a user than can still connect to the cluster through messaging protocols,
	// but cannot perform any management actions.
	// For more information, see https://www.rabbitmq.com/management.html#permissions.
	Tags []UserTag `json:"tags,omitempty"`
	// Reference to the RabbitmqCluster that the user will be created for. This cluster must
	// exist for the User object to be created.
	// +kubebuilder:validation:Required
	RabbitmqClusterReference RabbitmqClusterReference `json:"rabbitmqClusterReference"`
	// TODO: Allow the provision of the user with a pre-defined password through a Secret here
	}

messaging-topology-operator/api/v1alpha1/queue_types.go

Lines 44 to 49 in 06637f5

	type RabbitmqClusterReference struct {
	// +kubebuilder:validation:Required
	Name string `json:"name"`
	// +kubebuilder:validation:Required
	Namespace string `json:"namespace"`
	}

I noticed that we allow to interact with RabbitmqCluster objects in any namespace in the cluster. I'm concerned that we might be allowing a human user Cody to create RabbitMQ primitives in a RabbitMQ cluster they might not have access to. For example, Cody has access only to namespace cody-dev and they create a User kind which references a RabbitmqCluster with name rabbit in namespace foobar. The topology operator will create the user primitive in RabbitMQ, granting Cody credentials to access said RabbitMQ instance.

My concern is that the operator might allow Cody to access RabbitMQ instances they are not supposed or intended to.

Should we remove the namespace aspect, effectively having a LocalObjectReference-like object?

[MirahImage]

This is a breaking change to the API, therefore we need to simultaneously bump the API version to v1alpha2 (issue #63)

[coro]

Just to clarify, this affects all topology objects, which all allow for a namespace field in the cluster reference.

[coro]

@n3wscott How would this proposed change affect knative?