examples readme: documentation explaining the two provided examples

Signed-off-by: hasheddan <georgedanielmangum@gmail.com>

Author: hasheddan

examples/README.md

@@ -0,0 +1,32 @@
+# Examples
+
+These two examples represent the usage of `controller-runtime` libraries for built-in Kubernetes resources as well as custom resources.
+
+## builtins/
+
+This example implements a custom controller and webhooks for the *existing* ReplicaSet resource.
+
+* `controller.go`: implements a reconciler for ReplicaSets
+* `mutatingwebhook.go`: implements a mutating webhook that adds an annotation to every incoming Pod ("example-mutating-admission-webhook" = "foo")
+* `validatingwebhook.go`: implements a validating webhook that checks to see if a Pod has the aforementioned annotation
+* `main.go`
+    1. Creates a new manager
+    2. Creates a new controller that watches both ReplicaSets and Pods and reconciles the objects with the implemented reconciler
+    3. Registers the mutating and validating webhooks with the manager
+    4. Starts the manager
+
+## crd/
+
+This example implements a *new* Kubernetes resource, ChaosPod, and creates a custom controller that watches it and webhooks that mutate and validate.
+
+* `pkg/`
+    * `resource.go`: defines the schema for the ChaosPod API and implements validate and mutate webhooks
+    * `groupversion_info.go`: specifies the Group and Version for the ChaosPod API
+    * `zz_generated.deepcopy.go`: deep copy functions generated by kubebuilder
+* `main.go`
+    1. Creates a new manager
+    2. Adds ChaosPod resource to the manager's schema
+    3. Implements a reconciler to execute the desired behavior of the ChaosPod API
+    4. Creates a new controller that watches ChaosPods and reconciles the objects with the implemented reconciler
+    5. Adds ChaosPod webhooks to manager
+    6. Starts the manager