fix: add missing http filters to the http filter chain

Signed-off-by: huabing zhao <[email protected]>

internal/xds/translator/httpfilters.go

@@ -165,9 +165,18 @@ func (t *Translator) patchHCMWithFilters(
 	// rate limit server configuration.
 	t.patchHCMWithRateLimit(mgr, irListener)
 
-	// Add the router filter
-	headerSettings := ptr.Deref(irListener.Headers, ir.HeaderSettings{})
-	mgr.HttpFilters = append(mgr.HttpFilters, filters.GenerateRouterFilter(headerSettings.EnableEnvoyHeaders))
+	// Add the router filter if it doesn't exist.
+	hasRouter := false
+	for _, filter := range mgr.HttpFilters {
+		if filter.Name == wellknown.Router {
+			hasRouter = true
+			break
+		}
+	}
+	if !hasRouter {
+		headerSettings := ptr.Deref(irListener.Headers, ir.HeaderSettings{})
+		mgr.HttpFilters = append(mgr.HttpFilters, filters.GenerateRouterFilter(headerSettings.EnableEnvoyHeaders))
+	}
 
 	// Sort the filters in the correct order.
 	mgr.HttpFilters = sortHTTPFilters(mgr.HttpFilters)

internal/xds/translator/translator.go

@@ -16,10 +16,12 @@ import (
 	endpointv3 "github.com/envoyproxy/go-control-plane/envoy/config/endpoint/v3"
 	listenerv3 "github.com/envoyproxy/go-control-plane/envoy/config/listener/v3"
 	routev3 "github.com/envoyproxy/go-control-plane/envoy/config/route/v3"
+	hcmv3 "github.com/envoyproxy/go-control-plane/envoy/extensions/filters/network/http_connection_manager/v3"
 	tlsv3 "github.com/envoyproxy/go-control-plane/envoy/extensions/transport_sockets/tls/v3"
 	matcherv3 "github.com/envoyproxy/go-control-plane/envoy/type/matcher/v3"
 	resourcev3 "github.com/envoyproxy/go-control-plane/pkg/resource/v3"
 	"github.com/envoyproxy/go-control-plane/pkg/wellknown"
+	"google.golang.org/protobuf/proto"
 	"google.golang.org/protobuf/types/known/anypb"
 	"google.golang.org/protobuf/types/known/wrapperspb"
 
@@ -171,6 +173,17 @@ func (t *Translator) processHTTPListenerXdsTranslation(
 					return err
 				}
 			}
+		} else {
+			// Add HTTP filters to the HCM if they have not yet been added,
+			// the filters have already been sorted in the correct order in the
+			// patchHCMWithFilters function.
+			hcm, err := findHCM(xdsListener.DefaultFilterChain)
+			if err != nil {
+				return err // should not happen
+			}
+			if err = t.patchHCMWithFilters(hcm, httpListener); err != nil {
+				return err
+			}
 		}
 
 		// Create a route config if we have not found one yet
@@ -320,6 +333,19 @@ func (t *Translator) processHTTPListenerXdsTranslation(
 	return errs
 }
 
+func findHCM(filterChain *listenerv3.FilterChain) (*hcmv3.HttpConnectionManager, error) {
+	for _, filter := range filterChain.Filters {
+		if filter.Name == wellknown.HTTPConnectionManager {
+			hcm := &hcmv3.HttpConnectionManager{}
+			if err := anypb.UnmarshalTo(filter.GetTypedConfig(), hcm, proto.UnmarshalOptions{}); err != nil {
+				return nil, err
+			}
+			return hcm, nil
+		}
+	}
+	return nil, errors.New("http connection manager not found")
+}
+
 func buildHTTP3AltSvcHeader(port int) *corev3.HeaderValueOption {
 	return &corev3.HeaderValueOption{
 		Append: &wrapperspb.BoolValue{Value: true},