From 028ed32b6f6d8900e1fbdbf78d364d789130df1b Mon Sep 17 00:00:00 2001
From: Alfonso Acosta <fons@weave.works>
Date: Fri, 16 Sep 2016 13:48:37 +0000
Subject: [PATCH] Simplify service node matching

---
 probe/endpoint/dns_snooper.go |  4 ++--
 probe/endpoint/reporter.go    |  2 +-
 render/detailed/summary.go    |  4 +---
 render/process.go             |  4 ++--
 render/theinternet.go         | 26 +++++++++++---------------
 5 files changed, 17 insertions(+), 23 deletions(-)

diff --git a/probe/endpoint/dns_snooper.go b/probe/endpoint/dns_snooper.go
index 3af147fd0..b07cc7367 100644
--- a/probe/endpoint/dns_snooper.go
+++ b/probe/endpoint/dns_snooper.go
@@ -207,9 +207,9 @@ func (s *DNSSnooper) processDNSMessage(dns *layers.DNS) {
 	newDomain := string(domainQueried)
 	for ip := range ips {
 		if existingDomains, err := s.reverseDNSCache.Get(ip); err != nil {
-			existingDomains.(map[string]struct{})[newDomain] = struct{}{}
-		} else {
 			s.reverseDNSCache.Set(ip, map[string]struct{}{newDomain: {}})
+		} else {
+			existingDomains.(map[string]struct{})[newDomain] = struct{}{}
 		}
 	}
 }
diff --git a/probe/endpoint/reporter.go b/probe/endpoint/reporter.go
index 58d59e50e..544311236 100644
--- a/probe/endpoint/reporter.go
+++ b/probe/endpoint/reporter.go
@@ -197,7 +197,7 @@ func (r *Reporter) makeEndpointNode(namespaceID string, addr string, port uint16
 		map[string]string{Addr: addr, Port: portStr})
 	names := r.dnsSnooper.CachedNamesForIP(addr)
 	if resolvedNames, err := r.reverseResolver.get(addr); err == nil {
-		append(names, resolvedNames)
+		names = append(names, resolvedNames...)
 	}
 	if len(names) > 0 {
 		node = node.WithSet(ReverseDNSNames, report.MakeStringSet(names...))
diff --git a/render/detailed/summary.go b/render/detailed/summary.go
index 3f68e2fad..f88a62a07 100644
--- a/render/detailed/summary.go
+++ b/render/detailed/summary.go
@@ -125,10 +125,8 @@ func pseudoNodeSummary(base NodeSummary, n report.Node) (NodeSummary, bool) {
 
 	// try rendering as a known service node
 	if strings.HasPrefix(n.ID, render.ServiceNodeIDPrefix) {
-		serviceID := n.ID[len(render.ServiceNodeIDPrefix):]
-		base.Label = render.KnownServicesForHumans[serviceID]
+		base.Label = n.ID[len(render.ServiceNodeIDPrefix):]
 		base.LabelMinor = ""
-		// TODO: use custom icons for known services?
 		base.Shape = report.Cloud
 		return base, true
 	}
diff --git a/render/process.go b/render/process.go
index 0e81261f1..bc344eba7 100644
--- a/render/process.go
+++ b/render/process.go
@@ -162,8 +162,8 @@ func toInternetNode(m report.Node) report.Node {
 	// a specific node if it is
 	hostnames, _ := m.Sets.Lookup(endpoint.ReverseDNSNames)
 	for _, hostname := range hostnames {
-		if serviceID, ok := lookupKnownService(hostname); ok {
-			return NewDerivedPseudoNode(ServiceNodeIDPrefix+serviceID, m)
+		if isKnownService(hostname) {
+			return NewDerivedPseudoNode(ServiceNodeIDPrefix+hostname, m)
 		}
 	}
 
diff --git a/render/theinternet.go b/render/theinternet.go
index cb24dcc55..d32ed6fb3 100644
--- a/render/theinternet.go
+++ b/render/theinternet.go
@@ -2,7 +2,7 @@ package render
 
 import (
 	"net"
-	"regexp"
+	"strings"
 
 	"github.com/weaveworks/scope/probe/host"
 	"github.com/weaveworks/scope/report"
@@ -12,26 +12,22 @@ var (
 	// ServiceNodeIDPrefix is how the ID all service pseudo nodes begin
 	ServiceNodeIDPrefix = "service-"
 
-	// KnownServicesForHumans contains a human-readable format of the service Ids
-	KnownServicesForHumans = map[string]string{
-		"aws-dynamo": "AWS Dynamo",
-		"aws-s3":     "AWS S3",
-	}
-
 	// Correspondence between hostnames and the service id they are part of
-	knownServicesMatchers = map[*regexp.Regexp]string{
-		regexp.MustCompile(`dynamodb.[^.]+.amazonaws.com`): "aws-dynamo",
-		regexp.MustCompile(`s3-[^.]+.amazonaws.com`):       "aws-s3",
+	knownServicesSuffixes = []string{
+		// See http://docs.aws.amazon.com/general/latest/gr/rande.html for fainer grained
+		// details
+		"amazonaws.com",
+		"googleapis.com",
 	}
 )
 
-func lookupKnownService(hostname string) (string, bool) {
-	for re, id := range knownServicesMatchers {
-		if re.MatchString(hostname) {
-			return id, true
+func isKnownService(hostname string) bool {
+	for _, suffix := range knownServicesSuffixes {
+		if strings.HasSuffix(hostname, suffix) {
+			return true
 		}
 	}
-	return "", false
+	return false
 }
 
 // LocalNetworks returns a superset of the networks (think: CIDRs) that are