feat: Refactor mcpServer.matchList config generation logic (#2207)

registry/nacos/mcpserver/watcher.go

@@ -27,6 +27,7 @@ import (
 	apiv1 "github.com/alibaba/higress/api/networking/v1"
 	"github.com/alibaba/higress/pkg/common"
 	common2 "github.com/alibaba/higress/pkg/ingress/kube/common"
+	"github.com/alibaba/higress/pkg/ingress/kube/mcpserver"
 	provider "github.com/alibaba/higress/registry"
 	"github.com/alibaba/higress/registry/memory"
 	"github.com/golang/protobuf/ptypes/wrappers"
@@ -56,7 +57,26 @@ const (
 	DefaultRefreshIntervalLimit = time.Second * 10
 	DefaultFetchPageSize        = 50
 	DefaultJoiner               = "@@"
-	NacosV3LabelKey             = "isV3"
+)
+
+var (
+	supportedProtocols = map[string]bool{
+		provider.HttpProtocol:         true,
+		provider.McpSSEProtocol:       true,
+		provider.McpStreambleProtocol: true,
+	}
+	protocolUpstreamTypeMapping = map[string]string{
+		provider.HttpProtocol:         mcpserver.UpstreamTypeRest,
+		provider.McpSSEProtocol:       mcpserver.UpstreamTypeSSE,
+		provider.McpStreambleProtocol: mcpserver.UpstreamTypeStreamable,
+	}
+	routeRewriteProtocols = map[string]bool{
+		provider.McpSSEProtocol:       true,
+		provider.McpStreambleProtocol: true,
+	}
+	mcpServerRewriteProtocols = map[string]bool{
+		provider.McpSSEProtocol: true,
+	}
 )
 
 var mcpServerLog = log.RegisterScope("McpServer", "Nacos Mcp Server Watcher process.")
@@ -431,7 +451,7 @@ func (w *watcher) getConfigCallback(namespace, group, dataId, data string) {
 		mcpServerLog.Errorf("Unmarshal config data to mcp server error:%v, namespace:%s, groupName:%s, dataId:%s", err, namespace, group, dataId)
 		return
 	}
-	if mcpServer.Protocol == provider.StdioProtocol || mcpServer.Protocol == provider.DubboProtocol || mcpServer.Protocol == provider.McpSSEProtocol {
+	if !supportedProtocols[mcpServer.Protocol] {
 		return
 	}
 	// process mcp service
@@ -670,7 +690,9 @@ func (w *watcher) getServiceCallback(server *provider.McpServer, configGroup, da
 	}
 	namespace := server.RemoteServerConfig.ServiceRef.NamespaceId
 	serviceName := server.RemoteServerConfig.ServiceRef.ServiceName
-	path := server.RemoteServerConfig.ExportPath
+	// Higress doesn't care about the MCP export path configured in nacos.
+	// Any path of the mcp server are supported in request routing.
+	path := "/"
 	protocol := server.Protocol
 	host := getNacosServiceFullHost(groupName, namespace, serviceName)
 
@@ -708,6 +730,8 @@ func (w *watcher) getServiceCallback(server *provider.McpServer, configGroup, da
 		w.cache.UpdateConfigCache(gvk.ServiceEntry, configKey, se, false)
 		vs := w.buildVirtualServiceForMcpServer(serviceEntry, configGroup, dataId, path, server)
 		w.cache.UpdateConfigCache(gvk.VirtualService, configKey, vs, false)
+		mcpServer := w.buildMcpServerForMcpServer(vs.Spec.(*v1alpha3.VirtualService), configGroup, dataId, path, server)
+		w.cache.UpdateConfigCache(mcpserver.GvkMcpServer, configKey, mcpServer, false)
 	}
 }
 
@@ -735,16 +759,28 @@ func (w *watcher) buildVirtualServiceForMcpServer(serviceentry *v1alpha3.Service
 	if path != "/" {
 		mergePath = mergePath + "/" + strings.TrimPrefix(path, "/")
 	}
+	mergePath = strings.TrimSuffix(mergePath, "/")
 
 	vs := &v1alpha3.VirtualService{
 		Hosts:    hosts,
 		Gateways: gateways,
 		Http: []*v1alpha3.HTTPRoute{{
 			Name: routeName,
+			// We need to use both exact and prefix matches here to ensure a proper matching.
+			// Also otherwise, prefix rewrite won't work correctly for Streamable HTTP transport, either.
+			// Example:
+			// Assume mergePath=/mcp/test prefixRewrite=/ requestPath=/mcp/test/abc
+			// If we only use prefix match, the rewritten path will be //abc.
 			Match: []*v1alpha3.HTTPMatchRequest{{
+				Uri: &v1alpha3.StringMatch{
+					MatchType: &v1alpha3.StringMatch_Exact{
+						Exact: mergePath,
+					},
+				},
+			}, {
 				Uri: &v1alpha3.StringMatch{
 					MatchType: &v1alpha3.StringMatch_Prefix{
-						Prefix: mergePath,
+						Prefix: mergePath + "/",
 					},
 				},
 			}},
@@ -759,9 +795,9 @@ func (w *watcher) buildVirtualServiceForMcpServer(serviceentry *v1alpha3.Service
 		}},
 	}
 
-	if server.Protocol == provider.McpStreambleProtocol {
+	if routeRewriteProtocols[server.Protocol] {
 		vs.Http[0].Rewrite = &v1alpha3.HTTPRewrite{
-			Uri: path,
+			Uri: "/",
 		}
 	}
 
@@ -777,6 +813,49 @@ func (w *watcher) buildVirtualServiceForMcpServer(serviceentry *v1alpha3.Service
 	}
 }
 
+func (w *watcher) buildMcpServerForMcpServer(vs *v1alpha3.VirtualService, group, dataId, path string, server *provider.McpServer) *config.Config {
+	if vs == nil {
+		return nil
+	}
+	domains := w.McpServerExportDomains
+	if len(domains) == 0 {
+		domains = []string{"*"}
+	}
+	name := fmt.Sprintf("%s-%s-%s", provider.IstioMcpAutoGeneratedMcpServerName, group, strings.TrimSuffix(dataId, ".json"))
+	httpRoute := vs.Http[0]
+	pathMatchValue := ""
+	for _, match := range httpRoute.Match {
+		if match.Uri != nil && match.Uri.GetExact() != "" {
+			pathMatchValue = match.Uri.GetExact()
+			break
+		}
+	}
+	protocol := server.Protocol
+
+	mcpServer := &mcpserver.McpServer{
+		Name:           name,
+		Domains:        domains,
+		PathMatchType:  mcpserver.PrefixMatchType,
+		PathMatchValue: pathMatchValue,
+		UpstreamType:   protocolUpstreamTypeMapping[protocol],
+	}
+	if mcpServerRewriteProtocols[protocol] {
+		mcpServer.EnablePathRewrite = true
+		mcpServer.PathRewritePrefix = "/"
+	}
+
+	mcpServerLog.Debugf("construct mcpserver %v", mcpServer)
+
+	return &config.Config{
+		Meta: config.Meta{
+			GroupVersionKind: mcpserver.GvkMcpServer,
+			Name:             name,
+			Namespace:        w.namespace,
+		},
+		Spec: mcpServer,
+	}
+}
+
 func (w *watcher) generateServiceEntry(host string, services []model.Instance) *v1alpha3.ServiceEntry {
 	portList := make([]*v1alpha3.ServicePort, 0)
 	endpoints := make([]*v1alpha3.WorkloadEntry, 0)
@@ -980,3 +1059,13 @@ func isValidIP(ipStr string) bool {
 	ip := net.ParseIP(ipStr)
 	return ip != nil
 }
+
+func normalizeRewritePathPrefix(path string) string {
+	if path == "" || path == "/" {
+		return "/"
+	}
+	if path[0] != '/' {
+		path = "/" + path
+	}
+	return strings.TrimSuffix(path, "/")
+}