fix(grpcserver): preserve projected backend refs by port

Author: mahmut-Abi

internal/grpcserver/snapshot_projection.go

@@ -2,6 +2,7 @@ package grpcserver
 
 import (
 	"log/slog"
+	"strconv"
 
 	"github.com/nantian-gw/gateway/internal/ir"
 	controlv1 "github.com/nantian-gw/proto/gateway/control/v1"
@@ -182,6 +183,12 @@ func filterBackendRefs(routeNamespace string, refs []ir.BackendRef, survivingBac
 		}
 		if _, ok := survivingBackends[backendProjectionKey(namespace, ref.Name)]; ok {
 			out = append(out, ref)
+			continue
+		}
+		if ref.Port != 0 {
+			if _, ok := survivingBackends[backendProjectionKey(namespace, portQualifiedBackendName(ref.Name, ref.Port))]; ok {
+				out = append(out, ref)
+			}
 		}
 	}
 	return out
@@ -282,6 +289,10 @@ func backendProjectionKey(namespace, name string) string {
 	return namespace + "/" + name
 }
 
+func portQualifiedBackendName(name string, port uint32) string {
+	return name + ":" + strconv.Itoa(int(port))
+}
+
 func supportsFeature(supported map[string]struct{}, feature string) bool {
 	_, ok := supported[feature]
 	return ok

internal/grpcserver/snapshot_projection_test.go

@@ -173,6 +173,133 @@ func TestProjectedSnapshotPreservesListenerWhenAllAttachedRoutesArePruned(t *tes
 	}
 }
 
+func TestProjectedSnapshotKeepsHTTPRouteWithPortQualifiedBackendName(t *testing.T) {
+	t.Parallel()
+
+	projected := buildProjectedProtoSnapshot(
+		&ir.Snapshot{
+			HTTPRoutes: []ir.HTTPRoute{{
+				Name:      "echo-route",
+				Namespace: "default",
+				Rules: []ir.HTTPRule{{
+					Name: "echo",
+					BackendRefs: []ir.BackendRef{{
+						Name:      "echo",
+						Namespace: "default",
+						Port:      80,
+					}},
+				}},
+			}},
+			Backends: []ir.BackendCluster{{
+				Name:           "echo:80",
+				Namespace:      "default",
+				Protocol:       "HTTP",
+				ConnectTimeout: 5 * time.Second,
+				Endpoints: []ir.BackendEndpoint{{
+					Address: "10.0.0.10",
+					Port:    80,
+					Healthy: true,
+				}},
+			}},
+		},
+		effectiveProjectionProfile([]string{featureCoreV1}),
+		slog.New(slog.NewTextHandler(io.Discard, nil)),
+	)
+
+	route := findProjectedHTTPRoute(t, projected, "echo-route")
+	if got := len(route.GetRules()); got != 1 {
+		t.Fatalf("http route rule count = %d, want 1", got)
+	}
+	if got := len(route.GetRules()[0].GetBackendRefs()); got != 1 {
+		t.Fatalf("http route backend ref count = %d, want 1", got)
+	}
+}
+
+func TestProjectedSnapshotKeepsGRPCRouteWithPortQualifiedBackendName(t *testing.T) {
+	t.Parallel()
+
+	projected := buildProjectedProtoSnapshot(
+		&ir.Snapshot{
+			GRPCRoutes: []ir.GRPCRoute{{
+				Name:      "echo-grpc",
+				Namespace: "default",
+				Rules: []ir.GRPCRule{{
+					Name: "echo",
+					BackendRefs: []ir.BackendRef{{
+						Name:      "echo",
+						Namespace: "default",
+						Port:      9000,
+					}},
+				}},
+			}},
+			Backends: []ir.BackendCluster{{
+				Name:           "echo:9000",
+				Namespace:      "default",
+				Protocol:       "GRPC",
+				ConnectTimeout: 5 * time.Second,
+				Endpoints: []ir.BackendEndpoint{{
+					Address: "10.0.0.11",
+					Port:    9000,
+					Healthy: true,
+				}},
+			}},
+		},
+		effectiveProjectionProfile([]string{featureCoreV1}),
+		slog.New(slog.NewTextHandler(io.Discard, nil)),
+	)
+
+	route := findProjectedGRPCRoute(t, projected, "echo-grpc")
+	if got := len(route.GetRules()); got != 1 {
+		t.Fatalf("grpc route rule count = %d, want 1", got)
+	}
+	if got := len(route.GetRules()[0].GetBackendRefs()); got != 1 {
+		t.Fatalf("grpc route backend ref count = %d, want 1", got)
+	}
+}
+
+func TestProjectedSnapshotKeepsStreamRouteWithPortQualifiedBackendName(t *testing.T) {
+	t.Parallel()
+
+	projected := buildProjectedProtoSnapshot(
+		&ir.Snapshot{
+			StreamRoutes: []ir.StreamRoute{{
+				Name:      "echo-stream",
+				Namespace: "default",
+				Kind:      "TCP",
+				Rules: []ir.StreamRule{{
+					Name: "echo",
+					BackendRefs: []ir.BackendRef{{
+						Name:      "echo",
+						Namespace: "default",
+						Port:      7000,
+					}},
+				}},
+			}},
+			Backends: []ir.BackendCluster{{
+				Name:           "echo:7000",
+				Namespace:      "default",
+				Protocol:       "TCP",
+				ConnectTimeout: 5 * time.Second,
+				Endpoints: []ir.BackendEndpoint{{
+					Address: "10.0.0.12",
+					Port:    7000,
+					Healthy: true,
+				}},
+			}},
+		},
+		effectiveProjectionProfile([]string{featureCoreV1}),
+		slog.New(slog.NewTextHandler(io.Discard, nil)),
+	)
+
+	route := findProjectedStreamRoute(t, projected, "echo-stream")
+	if got := len(route.GetRules()); got != 1 {
+		t.Fatalf("stream route rule count = %d, want 1", got)
+	}
+	if got := len(route.GetRules()[0].GetBackendRefs()); got != 1 {
+		t.Fatalf("stream route backend ref count = %d, want 1", got)
+	}
+}
+
 func projectionTestSnapshot() *ir.Snapshot {
 	return &ir.Snapshot{
 		ID:          "projection-snapshot",