update tests and changelog

CHANGELOG.md

@@ -214,6 +214,7 @@ Adding a new version? You'll need three changes:
   where `<hash>` is the hash result of the calculated name, like
   `httproute.default.svc.default.a-long-long-long-service-name.80_combined.00001111222233334444aaaabbbbcccc`.
   [#6711](https://github.com/Kong/kubernetes-ingress-controller/pull/6711)
+  [#6766](https://github.com/Kong/kubernetes-ingress-controller/pull/6766)
 - The new tag `k8s-named-route-rule` is added to a Kong Route, in the case when mapped `HTTPRoute`, `GRPCRoute`,
   `TCPRoute`, `TLSRoute` or `UDPRoute` has one or many route rules named (filled `spec.rules[*].name` field),
   those names will be propagated to one or many instances of aforementioned tag.
@@ -224,7 +225,6 @@ Adding a new version? You'll need three changes:
   This can reduce the memory usage in scenarios with a large number of giant secrets.
   [#6795](https://github.com/Kong/kubernetes-ingress-controller/pull/6795)
 
-
 ## [3.3.1]
 
 > Release date: 2024-08-28

internal/dataplane/translator/subtranslator/httproute.go

@@ -54,6 +54,8 @@ type HTTPRoutesTranslationResult struct {
 	HTTPRouteNameToTranslationErrors map[k8stypes.NamespacedName][]error
 }
 
+type splitHTTPRouteMatchesWithPrioritiesGroupedByRule map[string][]SplitHTTPRouteMatchToKongRoutePriority
+
 // TranslateHTTPRoutesToKongstateServices translates a set of HTTPRoutes to kongstate services,
 // and collect the translation errors in the process of translating.
 func TranslateHTTPRoutesToKongstateServices(
@@ -65,20 +67,12 @@ func TranslateHTTPRoutesToKongstateServices(
 ) HTTPRoutesTranslationResult {
 	serviceNameToRules := groupRulesFromHTTPRoutesByKongServiceName(routes, combinedServicesFromDifferentHTTPRoutes)
 
-	// first, split HTTPRoutes by hostnames and matches.
-	ruleToSplitMatchesWithPriorities := make(map[string][]SplitHTTPRouteMatchToKongRoutePriority)
+	// When feature flag expression routes is enabled, we need first split the matches and assign priorities to them
+	// to set proper priorities to the translated Kong routes for satisfying the specification of priorities of HTTPRoute matches:
+	// https://gateway-api.sigs.k8s.io/reference/spec/#gateway.networking.k8s.io/v1.HTTPRouteRule
+	ruleToSplitMatchesWithPriorities := make(splitHTTPRouteMatchesWithPrioritiesGroupedByRule)
 	if expressionRoutes {
-		splitHTTPRouteMatches := []SplitHTTPRouteMatch{}
-		for _, route := range routes {
-			splitHTTPRouteMatches = append(splitHTTPRouteMatches, SplitHTTPRoute(route)...)
-		}
-		// assign priorities to split HTTPRoutes.
-		splitHTTPRouteMatchesWithPriorities := AssignRoutePriorityToSplitHTTPRouteMatches(logger, splitHTTPRouteMatches)
-		for _, matchWithPriority := range splitHTTPRouteMatchesWithPriorities {
-			sourceRoute := matchWithPriority.Match.Source
-			ruleKey := fmt.Sprintf("%s/%s.%d", sourceRoute.Namespace, sourceRoute.Name, matchWithPriority.Match.RuleIndex)
-			ruleToSplitMatchesWithPriorities[ruleKey] = append(ruleToSplitMatchesWithPriorities[ruleKey], matchWithPriority)
-		}
+		ruleToSplitMatchesWithPriorities = groupHTTPRouteMatchesWithPrioritiesByRule(logger, routes)
 	}
 
 	kongstateServiceCache := map[string]kongstate.Service{}
@@ -274,7 +268,7 @@ func translateHTTPRouteRulesMetaToKongstateService(
 	}
 
 	if expressionRoutes {
-		routes, err := translateHTTPRouteRulesMetaToKongstateRoutesWithExpression(matchesWithPriorities)
+		routes, err := translateSplitHTTPRouteMatchesToKongstateRoutesWithExpression(matchesWithPriorities)
 		if err != nil {
 			return kongstate.Service{}, err
 		}
@@ -401,24 +395,6 @@ func translateHTTPRouteRulesMetaToKongstateRoutes(
 	return routes, nil
 }
 
-func translateHTTPRouteRulesMetaToKongstateRoutesWithExpression(
-	matchesWithPriorities []SplitHTTPRouteMatchToKongRoutePriority,
-) ([]kongstate.Route, error) {
-	routes := []kongstate.Route{}
-	for _, matchWithPriority := range matchesWithPriorities {
-		// Since each match is assigned a deterministic priority, we have to generate one route for each split match
-		// because every match have a different priority.
-		// TODO: update the algorithm to assign priorities to matches to make it possible to consilidate some matches.
-		// For example, we can assign the same priority to multiple matches from the same rule if they tie on the priority from the fixed fields.
-		route, err := KongExpressionRouteFromHTTPRouteMatchWithPriority(matchWithPriority)
-		if err != nil {
-			return []kongstate.Route{}, err
-		}
-		routes = append(routes, *route)
-	}
-	return routes, nil
-}
-
 // extractUniqueHTTPRoutes extracts unique HTTPRoutes in a grouped list of HTTPRouteRuleMeta.
 func extractUniqueHTTPRoutes(rulesMeta []httpRouteRuleMeta) []*gatewayapi.HTTPRoute {
 	routes := lo.Map(rulesMeta, func(m httpRouteRuleMeta, _ int) *gatewayapi.HTTPRoute {
@@ -558,7 +534,6 @@ func (m httpRouteRuleMeta) getKongServiceNameByBackendRefs() string {
 		hash := sha256.Sum256([]byte(name))
 		// We have already returned when there are no backends in the rule, so it is safe to use backendNames[0].
 		trimmedName := fmt.Sprintf("httproute.%s.svc.%s_combined.%x", m.parentRoute.Namespace, backendNames[0], hash)
-		// REVIEW: should we emit a log here to tell that the name is trimmed? And should we record the original long name?
 		return trimmedName
 	}
 	return name

internal/dataplane/translator/subtranslator/httproute_atc.go

@@ -451,14 +451,14 @@ func (t HTTPRoutePriorityTraits) EncodeToPriority() RoutePriorityType {
 	return priority
 }
 
-// AssignRoutePriorityToSplitHTTPRouteMatches assigns priority to
+// assignRoutePriorityToSplitHTTPRouteMatches assigns priority to
 // ALL split matches from ALL HTTPRoutes in the cache.
 // Firstly assign "fixed" bits by the following fields of the match:
 // hostname, path type, path length, method match, number of header matches, number of query param matches.
 // If ties exists in the first step, where multiple matches has the same priority
 // calculated from the fields, we run a sort for the matches in the tie
 // and assign the bits for "relative order" according to the sorting result of these matches.
-func AssignRoutePriorityToSplitHTTPRouteMatches(
+func assignRoutePriorityToSplitHTTPRouteMatches(
 	logger logr.Logger,
 	splitHTTPRouteMatches []SplitHTTPRouteMatch,
 ) []SplitHTTPRouteMatchToKongRoutePriority {
@@ -541,9 +541,9 @@ func compareSplitHTTPRouteMatchesRelativePriority(match1, match2 SplitHTTPRouteM
 	return true
 }
 
-// KongExpressionRouteFromHTTPRouteMatchWithPriority translates a split HTTPRoute match into expression
+// kongExpressionRouteFromHTTPRouteMatchWithPriority translates a split HTTPRoute match into expression
 // based kong route with assigned priority.
-func KongExpressionRouteFromHTTPRouteMatchWithPriority(
+func kongExpressionRouteFromHTTPRouteMatchWithPriority(
 	httpRouteMatchWithPriority SplitHTTPRouteMatchToKongRoutePriority,
 ) (*kongstate.Route, error) {
 	match := httpRouteMatchWithPriority.Match
@@ -607,20 +607,44 @@ func KongExpressionRouteFromHTTPRouteMatchWithPriority(
 	return r, nil
 }
 
-// KongServiceNameFromSplitHTTPRouteMatch generates service name from split HTTPRoute match.
-// since one HTTPRoute may be split by hostname and rule, the service name will be generated
-// in the format "httproute.<namespace>.<name>.<hostname>.<rule index>".
-// For example: `httproute.default.example.foo.com.0`.
-func KongServiceNameFromSplitHTTPRouteMatch(match SplitHTTPRouteMatch) string {
-	httproute := match.Source
-	hostname := "_"
-	if len(match.Hostname) > 0 {
-		hostname = strings.ReplaceAll(match.Hostname, "*", "_")
+// groupHTTPRouteMatchesWithPrioritiesByRule groups split HTTPRoute matches that has priorities assigned by the source HTTPRoute rule,.
+func groupHTTPRouteMatchesWithPrioritiesByRule(
+	logger logr.Logger, routes []*gatewayapi.HTTPRoute,
+) splitHTTPRouteMatchesWithPrioritiesGroupedByRule {
+	//
+	splitHTTPRouteMatches := []SplitHTTPRouteMatch{}
+	for _, route := range routes {
+		splitHTTPRouteMatches = append(splitHTTPRouteMatches, SplitHTTPRoute(route)...)
+	}
+	// assign priorities to split HTTPRoutes.
+	splitHTTPRouteMatchesWithPriorities := assignRoutePriorityToSplitHTTPRouteMatches(logger, splitHTTPRouteMatches)
+
+	// group the matches with priorities by its source HTTPRoute rule.
+	ruleToSplitMatchesWithPriorities := splitHTTPRouteMatchesWithPrioritiesGroupedByRule{}
+	for _, matchWithPriority := range splitHTTPRouteMatchesWithPriorities {
+		sourceRoute := matchWithPriority.Match.Source
+		ruleKey := fmt.Sprintf("%s/%s.%d", sourceRoute.Namespace, sourceRoute.Name, matchWithPriority.Match.RuleIndex)
+		ruleToSplitMatchesWithPriorities[ruleKey] = append(ruleToSplitMatchesWithPriorities[ruleKey], matchWithPriority)
+	}
+	return ruleToSplitMatchesWithPriorities
+}
+
+// translateSplitHTTPRouteMatchesToKongstateRoutesWithExpression translates a list of split HTTPRoute matches with assigned priorities
+// that are poiting to the same service to list of kongstate route with expressions.
+func translateSplitHTTPRouteMatchesToKongstateRoutesWithExpression(
+	matchesWithPriorities []SplitHTTPRouteMatchToKongRoutePriority,
+) ([]kongstate.Route, error) {
+	routes := []kongstate.Route{}
+	for _, matchWithPriority := range matchesWithPriorities {
+		// Since each match is assigned a deterministic priority, we have to generate one route for each split match
+		// because every match have a different priority.
+		// TODO: update the algorithm to assign priorities to matches to make it possible to consolidate some matches.
+		// For example, we can assign the same priority to multiple matches from the same rule if they tie on the priority from the fixed fields.
+		route, err := kongExpressionRouteFromHTTPRouteMatchWithPriority(matchWithPriority)
+		if err != nil {
+			return []kongstate.Route{}, err
+		}
+		routes = append(routes, *route)
 	}
-	return fmt.Sprintf("httproute.%s.%s.%s.%d",
-		httproute.Namespace,
-		httproute.Name,
-		hostname,
-		match.RuleIndex,
-	)
+	return routes, nil
 }