Eventing v0.5 updates (#1125)

Author: samodell

docs/eventing/README.md

@@ -39,9 +39,23 @@ generic interfaces that can be implemented by multiple Kubernetes resources:
    returned events may be further processed in the same way that events from an
    external event source are processed.
 
+### Event brokers and triggers
+
+As of v0.5, Knative Eventing defines Broker and Trigger objects to make it
+easier to filter events.
+
+A Broker provides a bucket of events which can be selected by attribute. It
+receives events and forwards them to subscribers defined by one or more matching
+Triggers.
+
+A Trigger describes a filter on event attributes which should be delivered to an
+Addressable. You can create as many Triggers as necessary.
+
+![Broker Trigger Diagram](./images/broker-trigger-overview.svg)
+
 ### Event channels and subscriptions
 
-Knative Eventing also defines a single event forwarding and persistence layer,
+Knative Eventing also defines an event forwarding and persistence layer,
 called a
 [**Channel**](https://github.com/knative/eventing/blob/master/pkg/apis/eventing/v1alpha1/channel_types.go#L36).
 Messaging implementations may provide implementations of Channels via the
@@ -73,25 +87,6 @@ subscription, and if you have any functions that make use of any external (to
 cluster) services, you must enable it also for them to work.
 [Follow the instructions to configure outbound network access](../serving/outbound-network-access.md).
 
-Install the core Knative Eventing (which provides an in-memory
-ChannelProvisioner) and the core sources (which provides the Kubernetes Events,
-GitHub, and "Container" Sources) with the following commands:
-
-```bash
-kubectl apply --filename https://github.com/knative/eventing/releases/download/v0.4.0/release.yaml
-kubectl apply --filename https://github.com/knative/eventing-sources/releases/download/v0.4.0/release.yaml
-```
-
-In addition to the core sources, there are [other sources](./sources/README.md)
-that you can install.
-
-This document will be updated as additional sources (which are custom resource
-definitions and an associated controller) and channels
-(ClusterChannelProvisioners and controllers) become available.
-
-Check out the [Configuration](#configuration) section to learn more about
-operating Knative Eventing.
-
 ## Architecture
 
 The eventing infrastructure supports two forms of event delivery at the moment:
@@ -127,7 +122,10 @@ Knative Eventing defines the following Sources in the
 `sources.eventing.knative.dev` API group. Types below are declared in golang
 format, but may be expressed as simple lists, etc in YAML. All Sources should be
 part of the `sources` category, so you can list all existing Sources with
-`kubectl get sources`. The currently-implemented Sources are described below:
+`kubectl get sources`. The currently-implemented Sources are described below.
+
+In addition to the core sources, there are [other sources](./sources/README.md)
+that you can install.
 
 _Want to implement your own source? Check out
 [the tutorial](./samples/writing-a-source/README.md)._
@@ -305,7 +303,7 @@ example.
 ## Getting Started
 
 - [Setup Knative Serving](../install/README.md)
-- [Install Eventing components](#installation)
+- [Install the Eventing component](#installation)
 - [Run samples](./samples/)
 
 ## Configuration