From 503f0b6dca24a2e967c6591ccea40610c0e1871c Mon Sep 17 00:00:00 2001
From: Umputun <umputun@gmail.com>
Date: Tue, 8 Jun 2021 15:32:35 -0500
Subject: [PATCH] drop regex group in source priority sorting #89

---
 app/discovery/discovery.go      | 10 ++++--
 app/discovery/discovery_test.go | 61 ++++++++++++++++++++++++++++++---
 2 files changed, 65 insertions(+), 6 deletions(-)

diff --git a/app/discovery/discovery.go b/app/discovery/discovery.go
index 172cc085..603cde82 100644
--- a/app/discovery/discovery.go
+++ b/app/discovery/discovery.go
@@ -74,6 +74,8 @@ const (
 	PIConsulCatalog ProviderID = "consul-catalog"
 )
 
+var reGroup = regexp.MustCompile(`(^.*)/\(.*\)`) // capture regex group lil (anything) from src like /blah/foo/(.*)
+
 // MatchType defines the type of mapper (rule)
 type MatchType int
 
@@ -327,9 +329,13 @@ func (s *Service) mergeLists() (res []URLMapper) {
 
 	// sort rules to make assets last and prioritize longer rules first
 	sort.Slice(res, func(i, j int) bool {
+
+		src1 := reGroup.ReplaceAllString(res[i].SrcMatch.String(), "$1")
+		src2 := reGroup.ReplaceAllString(res[j].SrcMatch.String(), "$1")
+
 		// sort by len first, to make longer matches first
-		if len(res[i].SrcMatch.String()) != len(res[j].SrcMatch.String()) {
-			return len(res[i].SrcMatch.String()) > len(res[j].SrcMatch.String())
+		if len(src1) != len(src2) {
+			return len(src1) > len(src2)
 		}
 		// if len identical sort by SrcMatch string to keep same SrcMatch grouped together
 		return res[i].SrcMatch.String() < res[j].SrcMatch.String()
diff --git a/app/discovery/discovery_test.go b/app/discovery/discovery_test.go
index 933d3b30..a4522051 100644
--- a/app/discovery/discovery_test.go
+++ b/app/discovery/discovery_test.go
@@ -62,10 +62,10 @@ func TestService_Run(t *testing.T) {
 	assert.Equal(t, context.DeadlineExceeded, err)
 	mappers := svc.Mappers()
 	assert.Equal(t, 3, len(mappers))
-	assert.Equal(t, PIFile, mappers[0].ProviderID)
-	assert.Equal(t, "*", mappers[0].Server)
-	assert.Equal(t, "^/api/svc1/(.*)", mappers[0].SrcMatch.String())
-	assert.Equal(t, "http://127.0.0.1:8080/blah1/$1", mappers[0].Dst)
+	assert.Equal(t, PIDocker, mappers[0].ProviderID)
+	assert.Equal(t, "localhost", mappers[0].Server)
+	assert.Equal(t, "/api/svc3/xyz", mappers[0].SrcMatch.String())
+	assert.Equal(t, "http://127.0.0.3:8080/blah3/xyz", mappers[0].Dst)
 
 	assert.Equal(t, 1, len(p1.EventsCalls()))
 	assert.Equal(t, 1, len(p2.EventsCalls()))
@@ -173,6 +173,59 @@ func TestService_Match(t *testing.T) {
 	}
 }
 
+func TestService_MatchConflictRegex(t *testing.T) {
+	p1 := &ProviderMock{
+		EventsFunc: func(ctx context.Context) <-chan ProviderID {
+			res := make(chan ProviderID, 1)
+			res <- PIFile
+			return res
+		},
+		ListFunc: func() ([]URLMapper, error) {
+			return []URLMapper{
+				{SrcMatch: *regexp.MustCompile("^/api/svc1/(.*)"), Dst: "http://127.0.0.1:8080/blah/$1", ProviderID: PIFile},
+				{SrcMatch: *regexp.MustCompile("^/api/svc1/cat"), Dst: "http://127.0.0.2:8080/cat", ProviderID: PIFile},
+				{SrcMatch: *regexp.MustCompile("^/api/svc1/abcd"), Dst: "http://127.0.0.3:8080/abcd", ProviderID: PIFile},
+			}, nil
+		},
+	}
+
+	svc := NewService([]Provider{p1}, time.Millisecond*100)
+	ctx, cancel := context.WithTimeout(context.Background(), 500*time.Millisecond)
+	defer cancel()
+
+	err := svc.Run(ctx)
+	require.Error(t, err)
+	assert.Equal(t, context.DeadlineExceeded, err)
+	assert.Equal(t, 3, len(svc.Mappers()))
+
+	tbl := []struct {
+		server, src string
+		res         Matches
+	}{
+		{"example.com", "/api/svc1/xyz/something", Matches{MTProxy, []MatchedRoute{
+			{Destination: "http://127.0.0.1:8080/blah/xyz/something", Alive: true}}}},
+		{"example.com", "/api/svc1/something", Matches{MTProxy, []MatchedRoute{
+			{Destination: "http://127.0.0.1:8080/blah/something", Alive: true}}}},
+		{"example.com", "/api/svc1/cat", Matches{MTProxy, []MatchedRoute{
+			{Destination: "http://127.0.0.2:8080/cat", Alive: true}}}},
+		{"example.com", "/api/svc1/abcd", Matches{MTProxy, []MatchedRoute{
+			{Destination: "http://127.0.0.3:8080/abcd", Alive: true}}}},
+	}
+
+	for i, tt := range tbl {
+		tt := tt
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
+			res := svc.Match(tt.server, tt.src)
+			require.Equal(t, len(tt.res.Routes), len(res.Routes), res.Routes)
+			for i := 0; i < len(res.Routes); i++ {
+				assert.Equal(t, tt.res.Routes[i].Alive, res.Routes[i].Alive)
+				assert.Equal(t, tt.res.Routes[i].Destination, res.Routes[i].Destination)
+			}
+			assert.Equal(t, tt.res.MatchType, res.MatchType)
+		})
+	}
+}
+
 func TestService_Servers(t *testing.T) {
 	p1 := &ProviderMock{
 		EventsFunc: func(ctx context.Context) <-chan ProviderID {