From d874266cf62412f5801621469436049e77bffebe Mon Sep 17 00:00:00 2001
From: Tom Wilkie <tom.wilkie@gmail.com>
Date: Tue, 1 Mar 2016 17:16:48 +0000
Subject: [PATCH 1/2] Stop mutating nodes in the rendering pipeline

---
 render/mapping.go    | 21 ++++++++++++---------
 render/topologies.go | 29 ++++++++++++++++-------------
 2 files changed, 28 insertions(+), 22 deletions(-)

diff --git a/render/mapping.go b/render/mapping.go
index 5f0f24381..2c78b33aa 100644
--- a/render/mapping.go
+++ b/render/mapping.go
@@ -527,13 +527,14 @@ func MapCountProcessName(n RenderableNode, _ report.Networks) RenderableNodes {
 		return RenderableNodes{n.ID: n}
 	}
 
+	output := n.Copy()
 	processes, _ := n.Node.Counters.Lookup(processesKey)
 	if processes == 1 {
-		n.LabelMinor = "1 process"
+		output.LabelMinor = "1 process"
 	} else {
-		n.LabelMinor = fmt.Sprintf("%d processes", processes)
+		output.LabelMinor = fmt.Sprintf("%d processes", processes)
 	}
-	return RenderableNodes{n.ID: n}
+	return RenderableNodes{output.ID: output}
 }
 
 // MapContainer2ContainerImage maps container RenderableNodes to container
@@ -757,13 +758,14 @@ func MapCountContainers(n RenderableNode, _ report.Networks) RenderableNodes {
 		return RenderableNodes{n.ID: n}
 	}
 
+	output := n.Copy()
 	containers, _ := n.Node.Counters.Lookup(ContainersKey)
 	if containers == 1 {
-		n.LabelMinor = "1 container"
+		output.LabelMinor = "1 container"
 	} else {
-		n.LabelMinor = fmt.Sprintf("%d containers", containers)
+		output.LabelMinor = fmt.Sprintf("%d containers", containers)
 	}
-	return RenderableNodes{n.ID: n}
+	return RenderableNodes{output.ID: output}
 }
 
 // MapCountPods maps 1:1 service nodes, counting the number of pods grouped
@@ -773,13 +775,14 @@ func MapCountPods(n RenderableNode, _ report.Networks) RenderableNodes {
 		return RenderableNodes{n.ID: n}
 	}
 
+	output := n.Copy()
 	pods, _ := n.Node.Counters.Lookup(podsKey)
 	if pods == 1 {
-		n.LabelMinor = "1 pod"
+		output.LabelMinor = "1 pod"
 	} else {
-		n.LabelMinor = fmt.Sprintf("%d pods", pods)
+		output.LabelMinor = fmt.Sprintf("%d pods", pods)
 	}
-	return RenderableNodes{n.ID: n}
+	return RenderableNodes{output.ID: output}
 }
 
 // trySplitAddr is basically ParseArbitraryNodeID, since its callsites
diff --git a/render/topologies.go b/render/topologies.go
index 496787e37..cedc1487e 100644
--- a/render/topologies.go
+++ b/render/topologies.go
@@ -42,6 +42,7 @@ func (r processWithContainerNameRenderer) Render(rpt report.Report) RenderableNo
 		SelectContainer,
 	).Render(rpt)
 
+	outputs := RenderableNodes{}
 	for id, p := range processes {
 		pid, ok := p.Node.Latest.Lookup(process.PID)
 		if !ok {
@@ -55,11 +56,11 @@ func (r processWithContainerNameRenderer) Render(rpt report.Report) RenderableNo
 		if !ok {
 			continue
 		}
-		p.LabelMinor = fmt.Sprintf("%s (%s:%s)", report.ExtractHostID(p.Node), container.LabelMajor, pid)
-		processes[id] = p
+		output := p.Copy()
+		output.LabelMinor = fmt.Sprintf("%s (%s:%s)", report.ExtractHostID(p.Node), container.LabelMajor, pid)
+		outputs[id] = output
 	}
-
-	return processes
+	return outputs
 }
 
 // ProcessWithContainerNameRenderer is a Renderer which produces a process
@@ -131,6 +132,7 @@ func (r containerWithHostIPsRenderer) Render(rpt report.Report) RenderableNodes
 		SelectHost,
 	).Render(rpt)
 
+	outputs := RenderableNodes{}
 	for id, c := range containers {
 		networkMode, ok := c.Node.Latest.Lookup(docker.ContainerNetworkMode)
 		if !ok || networkMode != docker.NetworkModeHost {
@@ -150,11 +152,11 @@ func (r containerWithHostIPsRenderer) Render(rpt report.Report) RenderableNodes
 			}
 		}
 
-		c.Sets = c.Sets.Add(docker.ContainerIPs, newIPs)
-		containers[id] = c
+		output := c.Copy()
+		output.Sets = c.Sets.Add(docker.ContainerIPs, newIPs)
+		outputs[id] = output
 	}
-
-	return containers
+	return outputs
 }
 
 // ContainerWithHostIPsRenderer is a Renderer which produces a container graph
@@ -175,6 +177,7 @@ func (r containerWithImageNameRenderer) Render(rpt report.Report) RenderableNode
 		SelectContainerImage,
 	).Render(rpt)
 
+	outputs := RenderableNodes{}
 	for id, c := range containers {
 		imageID, ok := c.Node.Latest.Lookup(docker.ImageID)
 		if !ok {
@@ -184,12 +187,12 @@ func (r containerWithImageNameRenderer) Render(rpt report.Report) RenderableNode
 		if !ok {
 			continue
 		}
-		c.Rank = ImageNameWithoutVersion(image.LabelMajor)
-		c.Latest = image.Latest.Merge(c.Latest)
-		containers[id] = c
+		output := c.Copy()
+		output.Rank = ImageNameWithoutVersion(image.LabelMajor)
+		output.Latest = image.Latest.Merge(c.Latest)
+		outputs[id] = output
 	}
-
-	return containers
+	return outputs
 }
 
 // ContainerWithImageNameRenderer is a Renderer which produces a container

From 19411b9f76f3471ae44896fa43ca295eb7d9d23d Mon Sep 17 00:00:00 2001
From: Tom Wilkie <tom.wilkie@gmail.com>
Date: Wed, 2 Mar 2016 10:35:11 +0000
Subject: [PATCH 2/2] Review feedback

---
 render/topologies.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/render/topologies.go b/render/topologies.go
index cedc1487e..ffe2772f5 100644
--- a/render/topologies.go
+++ b/render/topologies.go
@@ -44,6 +44,7 @@ func (r processWithContainerNameRenderer) Render(rpt report.Report) RenderableNo
 
 	outputs := RenderableNodes{}
 	for id, p := range processes {
+		outputs[id] = p
 		pid, ok := p.Node.Latest.Lookup(process.PID)
 		if !ok {
 			continue
@@ -134,6 +135,7 @@ func (r containerWithHostIPsRenderer) Render(rpt report.Report) RenderableNodes
 
 	outputs := RenderableNodes{}
 	for id, c := range containers {
+		outputs[id] = c
 		networkMode, ok := c.Node.Latest.Lookup(docker.ContainerNetworkMode)
 		if !ok || networkMode != docker.NetworkModeHost {
 			continue
@@ -179,6 +181,7 @@ func (r containerWithImageNameRenderer) Render(rpt report.Report) RenderableNode
 
 	outputs := RenderableNodes{}
 	for id, c := range containers {
+		outputs[id] = c
 		imageID, ok := c.Node.Latest.Lookup(docker.ImageID)
 		if !ok {
 			continue