Doc updates for controller namespace

Make all namespace settings explicit and add more documentation around
setting appropriate namespace when installing.

deploy/kubernetes/snapshot-controller/rbac-snapshot-controller.yaml

@@ -1,8 +1,15 @@
 # RBAC file for the snapshot controller.
+#
+# The snapshot controller implements the control loop for CSI snapshot functionality.
+# It should be installed as part of the base Kubernetes distribution in an appropriate
+# namespace for components implementing base system functionality. For installing with
+# Vanilla Kubernetes, kube-system makes sense for the namespace.
+
 apiVersion: v1
 kind: ServiceAccount
 metadata:
   name: snapshot-controller
+  namespace: default # TODO: replace with the namespace you want for your controller, e.g. kube-system
 
 ---
 kind: ClusterRole
@@ -44,8 +51,7 @@ metadata:
 subjects:
   - kind: ServiceAccount
     name: snapshot-controller
-    # replace with non-default namespace name
-    namespace: default
+    namespace: default # TODO: replace with the namespace you want for your controller, e.g. kube-system
 roleRef:
   kind: ClusterRole
   # change the name also here if the ClusterRole gets renamed
@@ -56,7 +62,7 @@ roleRef:
 kind: Role
 apiVersion: rbac.authorization.k8s.io/v1
 metadata:
-  namespace: default # TODO: replace with the namespace you want for your controller
+  namespace: default # TODO: replace with the namespace you want for your controller, e.g. kube-system
   name: snapshot-controller-leaderelection
 rules:
 - apiGroups: ["coordination.k8s.io"]
@@ -68,11 +74,11 @@ kind: RoleBinding
 apiVersion: rbac.authorization.k8s.io/v1
 metadata:
   name: snapshot-controller-leaderelection
-  namespace: default # TODO: replace with the namespace you want for your controller
+  namespace: default # TODO: replace with the namespace you want for your controller, e.g. kube-system
 subjects:
   - kind: ServiceAccount
     name: snapshot-controller
-    namespace: default # TODO: replace with the namespace you want for your controller
+    namespace: default # TODO: replace with the namespace you want for your controller, e.g. kube-system
 roleRef:
   kind: Role
   name: snapshot-controller-leaderelection

deploy/kubernetes/snapshot-controller/setup-snapshot-controller.yaml

@@ -1,10 +1,16 @@
 # This YAML file shows how to deploy the snapshot controller
 
+# The snapshot controller implements the control loop for CSI snapshot functionality.
+# It should be installed as part of the base Kubernetes distribution in an appropriate
+# namespace for components implementing base system functionality. For installing with
+# Vanilla Kubernetes, kube-system makes sense for the namespace.
+
 ---
 kind: StatefulSet
 apiVersion: apps/v1
 metadata:
   name: snapshot-controller
+  namespace: default # TODO: replace with the namespace you want for your controller, e.g. kube-system
 spec:
   serviceName: "snapshot-controller"
   replicas: 1