join with original renderer in ConnectionJoin

This guarantees that the output won't contain bare nodes containing
just an id and topology, as produced by ipToNode. Previously this was
ensured by calling convention, now it's ensured by construction.

render/container.go

@@ -36,12 +36,7 @@ var ContainerRenderer = MakeFilter(
 			MapProcess2Container,
 			ColorConnectedProcessRenderer,
 		),
-
-		// This mapper brings in connections by joining with container
-		// IPs.
 		ConnectionJoin(MapContainer2IP, SelectContainer),
-
-		SelectContainer,
 	),
 )
 
@@ -68,12 +63,15 @@ func ConnectionJoin(toIPs func(report.Node) []string, r Renderer) Renderer {
 		return result
 	}
 
-	return MakeMap(
-		ipToNode,
-		MakeReduce(
-			MakeMap(nodeToIP, r),
-			mapEndpoint2IP,
+	return MakeReduce(
+		MakeMap(
+			ipToNode,
+			MakeReduce(
+				MakeMap(nodeToIP, r),
+				mapEndpoint2IP,
+			),
 		),
+		r,
 	)
 }
 

render/pod.go

@@ -48,8 +48,7 @@ var PodRenderer = ConditionalRenderer(renderKubernetesTopologies,
 					),
 				),
 			),
-			selectPodsWithDeployments{},
-			ConnectionJoin(MapPod2IP, SelectPod),
+			ConnectionJoin(MapPod2IP, selectPodsWithDeployments{}),
 		),
 	),
 )