From 85bfcddb3ff50550ba0445d95a82394df4c71bdd Mon Sep 17 00:00:00 2001
From: Tom Wilkie <tom@weave.works>
Date: Sun, 6 Sep 2015 16:26:57 +0000
Subject: [PATCH] Prevent short lived connections appearing as pseudo nodes in
 the applications view.

---
 probe/endpoint/reporter.go | 32 ++++++++++++++++++++++----------
 render/mapping.go          | 13 ++++++++++---
 2 files changed, 32 insertions(+), 13 deletions(-)

diff --git a/probe/endpoint/reporter.go b/probe/endpoint/reporter.go
index bd71224b7..81d4b78ec 100644
--- a/probe/endpoint/reporter.go
+++ b/probe/endpoint/reporter.go
@@ -14,8 +14,9 @@ import (
 
 // Node metadata keys.
 const (
-	Addr = "addr" // typically IPv4
-	Port = "port"
+	Addr        = "addr" // typically IPv4
+	Port        = "port"
+	Conntracked = "conntracked"
 )
 
 // Reporter generates Reports containing the Endpoint topology.
@@ -102,18 +103,27 @@ func (r *Reporter) Report() (report.Report, error) {
 			localAddr  = conn.LocalAddress.String()
 			remoteAddr = conn.RemoteAddress.String()
 		)
-		r.addConnection(&rpt, localAddr, remoteAddr, localPort, remotePort, &conn.Proc)
+		extraNodeInfo := report.MakeNode()
+		if conn.Proc.PID > 0 {
+			extraNodeInfo = extraNodeInfo.WithMetadata(report.Metadata{
+				process.PID: strconv.FormatUint(uint64(conn.Proc.PID), 10),
+			})
+		}
+		r.addConnection(&rpt, localAddr, remoteAddr, localPort, remotePort, &extraNodeInfo, nil)
 	}
 
 	if r.conntracker != nil {
+		extraNodeInfo := report.MakeNode().WithMetadata(report.Metadata{
+			Conntracked: "true",
+		})
 		r.conntracker.WalkFlows(func(f Flow) {
 			var (
-				localPort  = f.Original.Layer4.SrcPort
-				remotePort = f.Original.Layer4.DstPort
+				localPort  = uint16(f.Original.Layer4.SrcPort)
+				remotePort = uint16(f.Original.Layer4.DstPort)
 				localAddr  = f.Original.Layer3.SrcIP
 				remoteAddr = f.Original.Layer3.DstIP
 			)
-			r.addConnection(&rpt, localAddr, remoteAddr, uint16(localPort), uint16(remotePort), nil)
+			r.addConnection(&rpt, localAddr, remoteAddr, localPort, remotePort, &extraNodeInfo, &extraNodeInfo)
 		})
 	}
 
@@ -124,7 +134,7 @@ func (r *Reporter) Report() (report.Report, error) {
 	return rpt, err
 }
 
-func (r *Reporter) addConnection(rpt *report.Report, localAddr, remoteAddr string, localPort, remotePort uint16, proc *procspy.Proc) {
+func (r *Reporter) addConnection(rpt *report.Report, localAddr, remoteAddr string, localPort, remotePort uint16, extraLocalNode, extraRemoteNode *report.Node) {
 	var (
 		localIsClient = int(localPort) > int(remotePort)
 		hostNodeID    = report.MakeHostNodeID(r.hostID)
@@ -188,10 +198,12 @@ func (r *Reporter) addConnection(rpt *report.Report, localAddr, remoteAddr strin
 			})
 		}
 
-		if proc != nil && proc.PID > 0 {
-			localNode.Metadata[process.PID] = strconv.FormatUint(uint64(proc.PID), 10)
+		if extraLocalNode != nil {
+			localNode = localNode.Merge(*extraLocalNode)
+		}
+		if extraRemoteNode != nil {
+			remoteNode = remoteNode.Merge(*extraRemoteNode)
 		}
-
 		rpt.Endpoint = rpt.Endpoint.WithNode(localEndpointNodeID, localNode)
 		rpt.Endpoint = rpt.Endpoint.WithNode(remoteEndpointNodeID, remoteNode)
 	}
diff --git a/render/mapping.go b/render/mapping.go
index 6945abdc7..366a34bab 100644
--- a/render/mapping.go
+++ b/render/mapping.go
@@ -45,9 +45,16 @@ func MapEndpointIdentity(m RenderableNode, local report.Networks) RenderableNode
 		return RenderableNodes{}
 	}
 
+	// We need to filter out short lived connections from this view,
+	// if they don't also have a pid; see #447
+	pid, pidOK := m.Metadata[process.PID]
+	_, conntracked := m.Metadata[endpoint.Conntracked]
+	if !pidOK && conntracked {
+		return RenderableNodes{}
+	}
+
 	// Nodes without a hostid are treated as psuedo nodes
-	_, ok = m.Metadata[report.HostNodeID]
-	if !ok {
+	if _, ok = m.Metadata[report.HostNodeID]; !ok {
 		// If the dstNodeAddr is not in a network local to this report, we emit an
 		// internet node
 		if ip := net.ParseIP(addr); ip != nil && !local.Contains(ip) {
@@ -80,7 +87,7 @@ func MapEndpointIdentity(m RenderableNode, local report.Networks) RenderableNode
 		rank  = major
 	)
 
-	if pid, ok := m.Metadata[process.PID]; ok {
+	if pidOK {
 		minor = fmt.Sprintf("%s (%s)", minor, pid)
 	}