Fix Route.ID() returns conflicting IDs (prometheus#3803)

* Update TestRouteID tests

This commit updates the TestRouteID tests to be more simple without
reducing test coverage. It also adds new cases that show a bug
in the existing code where conflicting IDs can be returned.

Signed-off-by: George Robinson <[email protected]>

* Fix Route.ID() returns conflicting IDs

This commit fixes a bug where Route.ID() returns conflicting IDs.
For example, the configuration:

    receiver: test
    routes:
    - matchers:
        - foo=bar
      continue: true
      routes:
      - matchers:
        - bar=baz
    - matchers:
        - foo=bar
      continue: true
      routes:
      - matchers:
        - bar=baz

Gives the following Route IDs:

    {}
    {}/{foo="bar"}/0
    {}/{foo="bar"}/{bar="baz"}/0
    {}/{foo="bar"}/1
    {}/{foo="bar"}/{bar="baz"}/0

When it should give these Route IDs:

    {}
    {}/{foo="bar"}/0
    {}/{foo="bar"}/0/{bar="baz"}/0
    {}/{foo="bar"}/1
    {}/{foo="bar"}/1/{bar="baz"}/0

Signed-off-by: George Robinson <[email protected]>

---------

Signed-off-by: George Robinson <[email protected]>

dispatch/route.go

@@ -17,6 +17,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"sort"
+	"strconv"
 	"strings"
 	"time"
 
@@ -184,22 +185,23 @@ func (r *Route) Key() string {
 func (r *Route) ID() string {
 	b := strings.Builder{}
 
-	position := -1
 	if r.parent != nil {
-		// Find the position in the same level leaf.
-		for i, cr := range r.parent.Routes {
-			if cr == r {
-				position = i
+		b.WriteString(r.parent.ID())
+		b.WriteRune('/')
+	}
+
+	b.WriteString(r.Matchers.String())
+
+	if r.parent != nil {
+		for i := range r.parent.Routes {
+			if r == r.parent.Routes[i] {
+				b.WriteRune('/')
+				b.WriteString(strconv.Itoa(i))
 				break
 			}
 		}
 	}
-	b.WriteString(r.Key())
 
-	if position > -1 {
-		b.WriteRune('/')
-		b.WriteString(fmt.Sprint(position))
-	}
 	return b.String()
 }
 

dispatch/route_test.go

@@ -856,68 +856,67 @@ routes:
 
 func TestRouteID(t *testing.T) {
 	in := `
-receiver: 'notify-def'
-
+receiver: default
 routes:
-- matchers: ['{owner="team-A"}', '{level!="critical"}']
-  receiver: 'notify-D'
-  group_by: [...]
-  continue: true
-- matchers: ['{owner="team-A"}', '{level!="critical"}']
-  receiver: 'notify-A'
+- continue: true
+  matchers:
+  - foo=bar
+  receiver: test1
   routes:
-  - matchers: ['{env="testing"}', '{baz!~".*quux"}']
-    receiver: 'notify-testing'
-    group_by: [...]
-  - match:
-      env: "production"
-    receiver: 'notify-productionA'
-    group_wait: 1m
-    continue: true
-  - matchers: [ env=~"produ.*", job=~".*"]
-    receiver: 'notify-productionB'
-    group_wait: 30s
-    group_interval: 5m
-    repeat_interval: 1h
-    group_by: ['job']
-- match_re:
-    owner: 'team-(B|C)'
-  group_by: ['foo', 'bar']
-  group_wait: 2m
-  receiver: 'notify-BC'
-- matchers: [group_by="role"]
-  group_by: ['role']
+  - matchers:
+    - bar=baz
+- continue: true
+  matchers:
+  - foo=bar
+  receiver: test1
   routes:
-  - matchers: ['{env="testing"}']
-    receiver: 'notify-testing'
-    routes:
-    - matchers: [wait="long"]
-      group_wait: 2m
+  - matchers:
+    - bar=baz
+- continue: true
+  matchers:
+  - foo=bar
+  receiver: test2
+  routes:
+  - matchers:
+    - bar=baz
+- continue: true
+  matchers:
+  - bar=baz
+  receiver: test3
+  routes:
+  - matchers:
+    - baz=qux
+  - matchers:
+    - qux=corge
+- continue: true
+  matchers:
+  - qux=~"[a-zA-Z0-9]+"
+- continue: true
+  matchers:
+  - corge!~"[0-9]+"
 `
-
-	var ctree config.Route
-	if err := yaml.UnmarshalStrict([]byte(in), &ctree); err != nil {
-		t.Fatal(err)
-	}
-	tree := NewRoute(&ctree, nil)
+	cr := config.Route{}
+	require.NoError(t, yaml.Unmarshal([]byte(in), &cr))
+	r := NewRoute(&cr, nil)
 
 	expected := []string{
 		"{}",
-		"{}/{level!=\"critical\",owner=\"team-A\"}/0",
-		"{}/{level!=\"critical\",owner=\"team-A\"}/1",
-		"{}/{level!=\"critical\",owner=\"team-A\"}/{baz!~\".*quux\",env=\"testing\"}/0",
-		"{}/{level!=\"critical\",owner=\"team-A\"}/{env=\"production\"}/1",
-		"{}/{level!=\"critical\",owner=\"team-A\"}/{env=~\"produ.*\",job=~\".*\"}/2",
-		"{}/{owner=~\"^(?:team-(B|C))$\"}/2",
-		"{}/{group_by=\"role\"}/3",
-		"{}/{group_by=\"role\"}/{env=\"testing\"}/0",
-		"{}/{group_by=\"role\"}/{env=\"testing\"}/{wait=\"long\"}/0",
+		"{}/{foo=\"bar\"}/0",
+		"{}/{foo=\"bar\"}/0/{bar=\"baz\"}/0",
+		"{}/{foo=\"bar\"}/1",
+		"{}/{foo=\"bar\"}/1/{bar=\"baz\"}/0",
+		"{}/{foo=\"bar\"}/2",
+		"{}/{foo=\"bar\"}/2/{bar=\"baz\"}/0",
+		"{}/{bar=\"baz\"}/3",
+		"{}/{bar=\"baz\"}/3/{baz=\"qux\"}/0",
+		"{}/{bar=\"baz\"}/3/{qux=\"corge\"}/1",
+		"{}/{qux=~\"[a-zA-Z0-9]+\"}/4",
+		"{}/{corge!~\"[0-9]+\"}/5",
 	}
 
-	var got []string
-	tree.Walk(func(r *Route) {
-		got = append(got, r.ID())
+	var actual []string
+	r.Walk(func(r *Route) {
+		actual = append(actual, r.ID())
 	})
-
-	require.ElementsMatch(t, got, expected)
+	require.ElementsMatch(t, actual, expected)
 }