Knative Eventing Sugar Controller

Knative Eventing Sugar Controller will react to special labels and annotations to produce or control eventing resources in a cluster or namespace. This allows cluster operators and developers to focus on creating fewer resources, and the underlying eventing infrastructure is created on-demand, and cleaned up when no longer needed.


The following command installs the Eventing Sugar Controller:

kubectl apply --filename

Automatic Broker Creation

One way to create a Broker is to manually apply a resource to a cluster using the default settings:

kubectl create -f - <<EOF
kind: Broker
  name: default
  namespace: default

There might be cases where automated Broker creation is desirable, such as on namespace creation, or on Trigger creation. The Sugar controller enables those use-cases:

  • When a Namespace is labeled with, the sugar controller will create a default Broker named “default” in that namespace.
  • When a Trigger is annotated with, the controller will create a Broker named by that Trigger in the Trigger’s Namespace.

When a Broker is deleted and the above labels or annotations are in-use, the Sugar Controller will automatically recreate a default Broker.

Namespace Examples

Creating a “default” Broker when creating a Namespace:

kubectl apply -f - <<EOF
apiVersion: v1
kind: Namespace
  name: example
  labels: enabled

To automatically create a Broker after a namespace exists, label the Namespace:

kubectl label namespace default

If the Broker named “default” already exists in the Namespace, the Sugar Controller will do nothing.

Trigger Examples

Create a Broker named by a Trigger ( in the Trigger’s Namespace:

kubectl apply -f - << EOF
kind: Trigger
  name: hello-sugar
  namespace: hello
  annotations: enabled
  broker: sugar
      apiVersion: v1
      kind: Service
      name: event-display

Note: If the named Broker already exists, the Sugar controller will do nothing, and the Trigger will not own the existing Broker.

This will make a Broker called “sugar” in the Namespace “hello”, and attempt to send events to the “event-display” service.

If the Broker of the given name already exists in the Namespace, the Sugar Controller will do nothing.

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