don't show Failed pods

these are not alive, and Scope generally only shows the living, not
the dead.

probe/kubernetes/pod.go

@@ -16,7 +16,10 @@ const (
 )
 
 // Pod states we handle specially
-const StateDeleted = "deleted"
+const (
+	StateDeleted = "deleted"
+	StateFailed  = "Failed"
+)
 
 // Pod represents a Kubernetes pod
 type Pod interface {

render/pod.go

@@ -46,7 +46,7 @@ var PodRenderer = Memoise(ConditionalRenderer(renderKubernetesTopologies,
 	MakeFilter(
 		func(n report.Node) bool {
 			state, ok := n.Latest.Lookup(kubernetes.State)
-			return (!ok || state != kubernetes.StateDeleted)
+			return !ok || !(state == kubernetes.StateDeleted || state == kubernetes.StateFailed)
 		},
 		MakeReduce(
 			PropagateSingleMetrics(report.Container,