filter out unconnected pseudo nodes on the outside

The change is necessitated by the removal of procspied/ebpf endpoint
filtering in the renderers, as a result of which the odd
conntracked-only, unconnected pseudo node can sneak through.

This new way of doing things also makes renderers more composable and
robust, and more directly reflects the objective:
- in the process topologies, filter out all unconnected nodes
- in all other topologies, filter out unconnected pseudo nodes

app/api_topologies.go

@@ -227,7 +227,7 @@ func MakeRegistry() *Registry {
 		},
 		APITopologyDesc{
 			id:       containersID,
-			renderer: render.ContainerWithImageNameRenderer,
+			renderer: render.FilterUnconnectedPseudo(render.ContainerWithImageNameRenderer),
 			Name:     "Containers",
 			Rank:     2,
 			Options:  containerFilters,
@@ -235,20 +235,20 @@ func MakeRegistry() *Registry {
 		APITopologyDesc{
 			id:       containersByHostnameID,
 			parent:   containersID,
-			renderer: render.ContainerHostnameRenderer,
+			renderer: render.FilterUnconnectedPseudo(render.ContainerHostnameRenderer),
 			Name:     "by DNS name",
 			Options:  containerFilters,
 		},
 		APITopologyDesc{
 			id:       containersByImageID,
 			parent:   containersID,
-			renderer: render.ContainerImageRenderer,
+			renderer: render.FilterUnconnectedPseudo(render.ContainerImageRenderer),
 			Name:     "by image",
 			Options:  containerFilters,
 		},
 		APITopologyDesc{
 			id:          podsID,
-			renderer:    render.PodRenderer,
+			renderer:    render.FilterUnconnectedPseudo(render.PodRenderer),
 			Name:        "Pods",
 			Rank:        3,
 			Options:     []APITopologyOptionGroup{unmanagedFilter},
@@ -257,7 +257,7 @@ func MakeRegistry() *Registry {
 		APITopologyDesc{
 			id:          replicaSetsID,
 			parent:      podsID,
-			renderer:    render.ReplicaSetRenderer,
+			renderer:    render.FilterUnconnectedPseudo(render.ReplicaSetRenderer),
 			Name:        "replica sets",
 			Options:     []APITopologyOptionGroup{unmanagedFilter},
 			HideIfEmpty: true,
@@ -265,7 +265,7 @@ func MakeRegistry() *Registry {
 		APITopologyDesc{
 			id:          kubeControllersID,
 			parent:      podsID,
-			renderer:    render.KubeControllerRenderer,
+			renderer:    render.FilterUnconnectedPseudo(render.KubeControllerRenderer),
 			Name:        "controllers",
 			Options:     []APITopologyOptionGroup{unmanagedFilter, k8sControllersTypeFilter},
 			HideIfEmpty: true,
@@ -273,14 +273,14 @@ func MakeRegistry() *Registry {
 		APITopologyDesc{
 			id:          servicesID,
 			parent:      podsID,
-			renderer:    render.PodServiceRenderer,
+			renderer:    render.FilterUnconnectedPseudo(render.PodServiceRenderer),
 			Name:        "services",
 			Options:     []APITopologyOptionGroup{unmanagedFilter},
 			HideIfEmpty: true,
 		},
 		APITopologyDesc{
 			id:          ecsTasksID,
-			renderer:    render.ECSTaskRenderer,
+			renderer:    render.FilterUnconnectedPseudo(render.ECSTaskRenderer),
 			Name:        "Tasks",
 			Rank:        3,
 			Options:     []APITopologyOptionGroup{unmanagedFilter},
@@ -289,14 +289,14 @@ func MakeRegistry() *Registry {
 		APITopologyDesc{
 			id:          ecsServicesID,
 			parent:      ecsTasksID,
-			renderer:    render.ECSServiceRenderer,
+			renderer:    render.FilterUnconnectedPseudo(render.ECSServiceRenderer),
 			Name:        "services",
 			Options:     []APITopologyOptionGroup{unmanagedFilter},
 			HideIfEmpty: true,
 		},
 		APITopologyDesc{
 			id:          swarmServicesID,
-			renderer:    render.SwarmServiceRenderer,
+			renderer:    render.FilterUnconnectedPseudo(render.SwarmServiceRenderer),
 			Name:        "services",
 			Rank:        3,
 			Options:     []APITopologyOptionGroup{unmanagedFilter},
@@ -304,14 +304,14 @@ func MakeRegistry() *Registry {
 		},
 		APITopologyDesc{
 			id:       hostsID,
-			renderer: render.HostRenderer,
+			renderer: render.FilterUnconnectedPseudo(render.HostRenderer),
 			Name:     "Hosts",
 			Rank:     4,
 		},
 		APITopologyDesc{
 			id:       weaveID,
 			parent:   hostsID,
-			renderer: render.WeaveRenderer,
+			renderer: render.FilterUnconnectedPseudo(render.WeaveRenderer),
 			Name:     "Weave Net",
 		},
 	)

render/container.go

@@ -68,13 +68,13 @@ func ConnectionJoin(r Renderer, toIPs func(report.Node) []string) Renderer {
 		return result
 	}
 
-	return FilterUnconnected(MakeMap(
+	return MakeMap(
 		ipToNode,
 		MakeReduce(
 			MakeMap(nodeToIP, r),
 			mapEndpoint2IP,
 		),
-	))
+	)
 }
 
 func ipToNode(n report.Node, _ report.Networks) report.Nodes {

render/filters.go

@@ -215,7 +215,7 @@ func Complement(f FilterFunc) FilterFunc {
 // FilterUnconnected produces a renderer that filters unconnected nodes
 // from the given renderer
 func FilterUnconnected(r Renderer) Renderer {
-	return MakeFilter(
+	return MakeFilterPseudo(
 		func(node report.Node) bool {
 			_, ok := node.Latest.Lookup(IsConnected)
 			return ok
@@ -224,6 +224,21 @@ func FilterUnconnected(r Renderer) Renderer {
 	)
 }
 
+// FilterUnconnectedPseudo produces a renderer that filters
+// unconnected pseudo nodes from the given renderer
+func FilterUnconnectedPseudo(r Renderer) Renderer {
+	return MakeFilterPseudo(
+		func(node report.Node) bool {
+			if !IsPseudoTopology(node) {
+				return true
+			}
+			_, ok := node.Latest.Lookup(IsConnected)
+			return ok
+		},
+		ColorConnected(r),
+	)
+}
+
 // Noop allows all nodes through
 func Noop(_ report.Node) bool { return true }