route shifting test

pkg/ambex/transforms.go

@@ -3,6 +3,9 @@ package ambex
 import (
 	// standard library
 	"context"
+	"crypto/md5"
+	"encoding/hex"
+	"encoding/json"
 	"fmt"
 
 	// third-party libraries
@@ -89,7 +92,7 @@ import (
 //                 "config_source": {
 //                   "ads": {}
 //                 },
-//                 "route_config_name": "ambassador-listener-8443-routeconfig-0"
+//                 "route_config_name": "ambassador-listener-8443-routeconfig-376bf87fb310abb282f452533940481d-0"
 //               }
 //             }
 //           }
@@ -100,7 +103,7 @@ import (
 //
 //  routes = [
 //    {
-//      "name": "ambassador-listener-8443-routeconfig-0",
+//      "name": "ambassador-listener-8443-routeconfig-376bf87fb310abb282f452533940481d-0",
 //      "virtual_hosts": [
 //        {
 //          "name": "ambassador-listener-8443-*",
@@ -114,6 +117,10 @@ import (
 // V3ListenerToRdsListener is the v3 variety of ListnerToRdsListener
 func V3ListenerToRdsListener(lnr *v3listener.Listener) (*v3listener.Listener, []*v3route.RouteConfiguration, error) {
 	l := proto.Clone(lnr).(*v3listener.Listener)
+
+	// Keep track of number of filter chain matches that hash to the same key for collisions
+	matchKeyIndex := make(map[string]int)
+
 	var routes []*v3route.RouteConfiguration
 	for _, fc := range l.FilterChains {
 		for _, f := range fc.Filters {
@@ -135,10 +142,20 @@ func V3ListenerToRdsListener(lnr *v3listener.Listener) (*v3listener.Listener, []
 					if rc.Name == "" {
 						// Generate a unique name for the RouteConfiguration that we can use to
 						// correlate the listener to the RDS record. We use the listener name plus
-						// an index because there can be more than one route configuration
+						// filter_chain_match hash because there can be more than one route configuration
 						// associated with a given listener.
-						rc.Name = fmt.Sprintf("%s-routeconfig-%d", l.Name, len(routes))
+						filterChainMatch, _ := json.Marshal(fc.GetFilterChainMatch())
+
+						// Use MD5 because it's decently fast and cryptographic security isn't needed.
+						matchHash := md5.Sum(filterChainMatch)
+						matchKey := hex.EncodeToString(matchHash[:])
+
+						rc.Name = fmt.Sprintf("%s-routeconfig-%s-%d", l.Name, matchKey, matchKeyIndex[matchKey])
+
+						// Add or update map entry for this filter chain key to dedupe those that hash to the same key.
+						matchKeyIndex[matchKey]++
 					}
+
 					routes = append(routes, rc)
 					// Now that we have extracted and named the RouteConfiguration, we change the
 					// RouteSpecifier from the inline RouteConfig variation to RDS via ADS. This

pkg/ambex/transforms_test.go

@@ -0,0 +1,89 @@
+package ambex
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"google.golang.org/protobuf/types/known/anypb"
+	"google.golang.org/protobuf/types/known/durationpb"
+	"google.golang.org/protobuf/types/known/wrapperspb"
+
+	v3Listener "github.com/emissary-ingress/emissary/v3/pkg/api/envoy/config/listener/v3"
+	v3Route "github.com/emissary-ingress/emissary/v3/pkg/api/envoy/config/route/v3"
+	v3Httpman "github.com/emissary-ingress/emissary/v3/pkg/api/envoy/extensions/filters/network/http_connection_manager/v3"
+	v3Wellknown "github.com/emissary-ingress/emissary/v3/pkg/envoy-control-plane/wellknown"
+)
+
+func TestV3ListenerToRdsListener(t *testing.T) {
+	testRoute := &v3Route.Route_Route{
+		Route: &v3Route.RouteAction{
+			ClusterSpecifier: &v3Route.RouteAction_Cluster{
+				Cluster: "cluster_quote_default_default",
+			},
+			PrefixRewrite: "/",
+			Timeout:       durationpb.New(3 * time.Second),
+		},
+	}
+
+	testHcm := &v3Httpman.HttpConnectionManager{
+		RouteSpecifier: &v3Httpman.HttpConnectionManager_RouteConfig{
+			RouteConfig: &v3Route.RouteConfiguration{
+				VirtualHosts: []*v3Route.VirtualHost{{
+					Name:    "emissary-ingress-listener-8080-*",
+					Domains: []string{"*"},
+					Routes: []*v3Route.Route{{
+						Match: &v3Route.RouteMatch{
+							PathSpecifier: &v3Route.RouteMatch_Prefix{
+								Prefix: "/backend/",
+							},
+						},
+						Action: testRoute,
+					}},
+				}},
+			},
+		},
+	}
+
+	anyTestHcm, err := anypb.New(testHcm)
+	require.NoError(t, err)
+
+	//Create a second identical Hcm
+	anyTestHcm2, err := anypb.New(testHcm)
+	require.NoError(t, err)
+
+	testListener := &v3Listener.Listener{
+		Name: "emissary-ingress-listener-8080",
+		FilterChains: []*v3Listener.FilterChain{{
+			Filters: []*v3Listener.Filter{{
+				Name:       v3Wellknown.HTTPConnectionManager,
+				ConfigType: &v3Listener.Filter_TypedConfig{TypedConfig: anyTestHcm},
+			}, {
+				Name:       v3Wellknown.HTTPConnectionManager,
+				ConfigType: &v3Listener.Filter_TypedConfig{TypedConfig: anyTestHcm2},
+			}},
+			FilterChainMatch: &v3Listener.FilterChainMatch{
+				DestinationPort: &wrapperspb.UInt32Value{Value: uint32(8080)},
+			},
+		}},
+	}
+
+	_, routes, err := V3ListenerToRdsListener(testListener)
+	require.NoError(t, err)
+
+	//Should have 2 routes
+	assert.Equal(t, 2, len(routes))
+
+	for i, rc := range routes {
+		// Confirm that the route name was transformed to the hashed version
+		assert.Equal(t, fmt.Sprintf("emissary-ingress-listener-8080-routeconfig-8c82e45fa3f94ab4e879543e0a1a30ac-%d", i), rc.GetName())
+
+		// Make sure the virtual hosts are unmodified
+		virtualHosts := rc.GetVirtualHosts()
+		assert.Equal(t, 1, len(virtualHosts))
+		assert.Equal(t, "emissary-ingress-listener-8080-*", virtualHosts[0].GetName())
+		assert.Equal(t, []string{"*"}, virtualHosts[0].GetDomains())
+	}
+}