address review comments

Signed-off-by: Clayton Gonsalves <clayton.gonsalves@reddit.com>

apis/projectcontour/v1alpha1/contourconfig.go

@@ -85,10 +85,18 @@ type ContourConfigurationSpec struct {
 	// Tracing defines properties for exporting trace data to OpenTelemetry.
 	Tracing *TracingConfig `json:"tracing,omitempty"`
 
-	// FeatureFlags defines toggle for new contour features.
+	// FeatureFlags defines toggle to enable new contour features.
+	// available toggles are
+	// useEndpointSlices - configures contour to fetch endpoint data
+	// from k8s endpoint slices. defaults to false and reading endpoint
+	// data from the k8s endpoints.
 	FeatureFlags FeatureFlags `json:"featureFlags,omitempty"`
 }
 
+// FeatureFlags defines the set of feature flags
+// to toggle new contour features.
+type FeatureFlags []string
+
 // XDSServerType is the type of xDS server implementation.
 type XDSServerType string
 
@@ -862,10 +870,3 @@ type ContourConfigurationList struct {
 	metav1.ListMeta `json:"metadata,omitempty"`
 	Items           []ContourConfiguration `json:"items"`
 }
-
-type FeatureFlags struct {
-	// useEndpointSlice configures contour to fetch endpoint data
-	// from k8s endpoint slices. defaults to false and reading endpoint
-	// data from the k8s endpoints.
-	UseEndpointSlice bool `json:"useEndpointSlice,omitempty"`
-}

apis/projectcontour/v1alpha1/contourconfig_helpers.go

@@ -17,9 +17,18 @@ import (
 	"fmt"
 	"strconv"
 
+	"golang.org/x/exp/slices"
 	"k8s.io/apimachinery/pkg/util/sets"
 )
 
+const (
+	featureFlagUseEndpointSlices string = "useEndpointSlices"
+)
+
+var featureFlagsMap = map[string]bool{
+	featureFlagUseEndpointSlices: true,
+}
+
 // Validate configuration that is not already covered by CRD validation.
 func (c *ContourConfigurationSpec) Validate() error {
 	// Validation of root configuration fields.
@@ -215,6 +224,20 @@ func (e *EnvoyTLS) SanitizedCipherSuites() []string {
 	return validatedCiphers
 }
 
+func (f FeatureFlags) Validate() error {
+	for _, featureFlag := range f {
+		if _, found := featureFlagsMap[featureFlag]; !found {
+			return fmt.Errorf("invalid contour configuration, unknown feature flag:%s", featureFlag)
+		}
+	}
+
+	return nil
+}
+
+func (f FeatureFlags) IsEndpointSliceEnabled() bool {
+	return slices.Contains(f, featureFlagUseEndpointSlices)
+}
+
 // Validate ensures that exactly one of ControllerName or GatewayRef are specified.
 func (g *GatewayConfig) Validate() error {
 	if g == nil {

apis/projectcontour/v1alpha1/contourconfig_helpers_test.go

@@ -14,6 +14,7 @@
 package v1alpha1_test
 
 import (
+	"fmt"
 	"testing"
 
 	"github.com/projectcontour/contour/apis/projectcontour/v1alpha1"
@@ -294,3 +295,39 @@ func TestAccessLogFormatExtensions(t *testing.T) {
 	}
 	assert.Empty(t, e3.AccessLogFormatterExtensions())
 }
+
+func TestFeatureFlagsValidate(t *testing.T) {
+	tests := []struct {
+		name     string
+		flags    v1alpha1.FeatureFlags
+		expected error
+	}{
+		{
+			name:     "valid flag",
+			flags:    v1alpha1.FeatureFlags{"useEndpointSlices"},
+			expected: nil,
+		},
+		{
+			name:     "invalid flag",
+			flags:    v1alpha1.FeatureFlags{"invalidFlag"},
+			expected: fmt.Errorf("invalid contour configuration, unknown feature flag:invalidFlag"),
+		},
+		{
+			name:     "mix of valid and invalid flags",
+			flags:    v1alpha1.FeatureFlags{"useEndpointSlices", "invalidFlag"},
+			expected: fmt.Errorf("invalid contour configuration, unknown feature flag:invalidFlag"),
+		},
+		{
+			name:     "empty flags",
+			flags:    v1alpha1.FeatureFlags{},
+			expected: nil,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := tt.flags.Validate()
+			assert.Equal(t, tt.expected, err)
+		})
+	}
+}

changelogs/unreleased/5745-clayton-gonsalves-minor.md

@@ -2,3 +2,5 @@
 
 This change optionally enables Contour to consume the kubernetes endpointslice API to determine the endpoints to configure Envoy with.
 Note: This change is off by default and is gated by the feature flag `useEndpointSlice`.
+
+This feature will be enabled by default in a future version on Contour once it has had sufficient bake time in production environments.

cmd/contour/serve.go

@@ -457,7 +457,7 @@ func (s *Server) doServe() error {
 
 	// Endpoints updates are handled directly by the EndpointsTranslator/EndpointSliceTranslator due to the high update volume.
 	var endpointHandler EndpointsTranslator
-	if contourConfiguration.FeatureFlags.UseEndpointSlice {
+	if contourConfiguration.FeatureFlags.IsEndpointSliceEnabled() {
 		endpointHandler = xdscache_v3.NewEndpointSliceTranslator(s.log.WithField("context", "endpointstranslator"))
 	} else {
 		endpointHandler = xdscache_v3.NewEndpointsTranslator(s.log.WithField("context", "endpointstranslator"))
@@ -600,7 +600,7 @@ func (s *Server) doServe() error {
 	}
 
 	// Inform on endpoints/endpointSlices.
-	if contourConfiguration.FeatureFlags.UseEndpointSlice {
+	if contourConfiguration.FeatureFlags.IsEndpointSliceEnabled() {
 		if err := informOnResource(&discoveryv1.EndpointSlice{}, &contour.EventRecorder{
 			Next:    endpointHandler,
 			Counter: contourMetrics.EventHandlerOperations,
@@ -612,7 +612,7 @@ func (s *Server) doServe() error {
 			Next:    endpointHandler,
 			Counter: contourMetrics.EventHandlerOperations,
 		}, s.mgr.GetCache()); err != nil {
-			s.log.WithError(err).WithField("resource", "endpointslices").Fatal("failed to create informer")
+			s.log.WithError(err).WithField("resource", "endpoints").Fatal("failed to create informer")
 		}
 	}
 

cmd/contour/servecontext.go

@@ -588,9 +588,7 @@ func (ctx *serveContext) convertToContourConfigurationSpec() contour_api_v1alpha
 		Policy:                      policy,
 		Metrics:                     &contourMetrics,
 		Tracing:                     tracingConfig,
-		FeatureFlags: contour_api_v1alpha1.FeatureFlags{
-			UseEndpointSlice: ctx.Config.FeatureFlags.UseEndpointSlice,
-		},
+		FeatureFlags:                ctx.Config.FeatureFlags,
 	}
 
 	xdsServerType := contour_api_v1alpha1.ContourServerType

examples/contour/01-crds.yaml

@@ -449,14 +449,13 @@ spec:
                     type: object
                 type: object
               featureFlags:
-                description: FeatureFlags defines toggle for new contour features.
-                properties:
-                  useEndpointSlice:
-                    description: useEndpointSlice configures contour to fetch endpoint
-                      data from k8s endpoint slices. defaults to false and reading
-                      endpoint data from the k8s endpoints.
-                    type: boolean
-                type: object
+                description: FeatureFlags defines toggle to enable new contour features.
+                  available toggles are useEndpointSlices - configures contour to
+                  fetch endpoint data from k8s endpoint slices. defaults to false
+                  and reading endpoint data from the k8s endpoints.
+                items:
+                  type: string
+                type: array
               gateway:
                 description: Gateway contains parameters for the gateway-api Gateway
                   that Contour is configured to serve traffic.
@@ -3899,14 +3898,13 @@ spec:
                         type: object
                     type: object
                   featureFlags:
-                    description: FeatureFlags defines toggle for new contour features.
-                    properties:
-                      useEndpointSlice:
-                        description: useEndpointSlice configures contour to fetch
-                          endpoint data from k8s endpoint slices. defaults to false
-                          and reading endpoint data from the k8s endpoints.
-                        type: boolean
-                    type: object
+                    description: FeatureFlags defines toggle to enable new contour
+                      features. available toggles are useEndpointSlices - configures
+                      contour to fetch endpoint data from k8s endpoint slices. defaults
+                      to false and reading endpoint data from the k8s endpoints.
+                    items:
+                      type: string
+                    type: array
                   gateway:
                     description: Gateway contains parameters for the gateway-api Gateway
                       that Contour is configured to serve traffic.

examples/render/contour-deployment.yaml

@@ -668,14 +668,13 @@ spec:
                     type: object
                 type: object
               featureFlags:
-                description: FeatureFlags defines toggle for new contour features.
-                properties:
-                  useEndpointSlice:
-                    description: useEndpointSlice configures contour to fetch endpoint
-                      data from k8s endpoint slices. defaults to false and reading
-                      endpoint data from the k8s endpoints.
-                    type: boolean
-                type: object
+                description: FeatureFlags defines toggle to enable new contour features.
+                  available toggles are useEndpointSlices - configures contour to
+                  fetch endpoint data from k8s endpoint slices. defaults to false
+                  and reading endpoint data from the k8s endpoints.
+                items:
+                  type: string
+                type: array
               gateway:
                 description: Gateway contains parameters for the gateway-api Gateway
                   that Contour is configured to serve traffic.
@@ -4118,14 +4117,13 @@ spec:
                         type: object
                     type: object
                   featureFlags:
-                    description: FeatureFlags defines toggle for new contour features.
-                    properties:
-                      useEndpointSlice:
-                        description: useEndpointSlice configures contour to fetch
-                          endpoint data from k8s endpoint slices. defaults to false
-                          and reading endpoint data from the k8s endpoints.
-                        type: boolean
-                    type: object
+                    description: FeatureFlags defines toggle to enable new contour
+                      features. available toggles are useEndpointSlices - configures
+                      contour to fetch endpoint data from k8s endpoint slices. defaults
+                      to false and reading endpoint data from the k8s endpoints.
+                    items:
+                      type: string
+                    type: array
                   gateway:
                     description: Gateway contains parameters for the gateway-api Gateway
                       that Contour is configured to serve traffic.

examples/render/contour-gateway-provisioner.yaml

@@ -463,14 +463,13 @@ spec:
                     type: object
                 type: object
               featureFlags:
-                description: FeatureFlags defines toggle for new contour features.
-                properties:
-                  useEndpointSlice:
-                    description: useEndpointSlice configures contour to fetch endpoint
-                      data from k8s endpoint slices. defaults to false and reading
-                      endpoint data from the k8s endpoints.
-                    type: boolean
-                type: object
+                description: FeatureFlags defines toggle to enable new contour features.
+                  available toggles are useEndpointSlices - configures contour to
+                  fetch endpoint data from k8s endpoint slices. defaults to false
+                  and reading endpoint data from the k8s endpoints.
+                items:
+                  type: string
+                type: array
               gateway:
                 description: Gateway contains parameters for the gateway-api Gateway
                   that Contour is configured to serve traffic.
@@ -3913,14 +3912,13 @@ spec:
                         type: object
                     type: object
                   featureFlags:
-                    description: FeatureFlags defines toggle for new contour features.
-                    properties:
-                      useEndpointSlice:
-                        description: useEndpointSlice configures contour to fetch
-                          endpoint data from k8s endpoint slices. defaults to false
-                          and reading endpoint data from the k8s endpoints.
-                        type: boolean
-                    type: object
+                    description: FeatureFlags defines toggle to enable new contour
+                      features. available toggles are useEndpointSlices - configures
+                      contour to fetch endpoint data from k8s endpoint slices. defaults
+                      to false and reading endpoint data from the k8s endpoints.
+                    items:
+                      type: string
+                    type: array
                   gateway:
                     description: Gateway contains parameters for the gateway-api Gateway
                       that Contour is configured to serve traffic.

examples/render/contour-gateway.yaml

@@ -674,14 +674,13 @@ spec:
                     type: object
                 type: object
               featureFlags:
-                description: FeatureFlags defines toggle for new contour features.
-                properties:
-                  useEndpointSlice:
-                    description: useEndpointSlice configures contour to fetch endpoint
-                      data from k8s endpoint slices. defaults to false and reading
-                      endpoint data from the k8s endpoints.
-                    type: boolean
-                type: object
+                description: FeatureFlags defines toggle to enable new contour features.
+                  available toggles are useEndpointSlices - configures contour to
+                  fetch endpoint data from k8s endpoint slices. defaults to false
+                  and reading endpoint data from the k8s endpoints.
+                items:
+                  type: string
+                type: array
               gateway:
                 description: Gateway contains parameters for the gateway-api Gateway
                   that Contour is configured to serve traffic.
@@ -4124,14 +4123,13 @@ spec:
                         type: object
                     type: object
                   featureFlags:
-                    description: FeatureFlags defines toggle for new contour features.
-                    properties:
-                      useEndpointSlice:
-                        description: useEndpointSlice configures contour to fetch
-                          endpoint data from k8s endpoint slices. defaults to false
-                          and reading endpoint data from the k8s endpoints.
-                        type: boolean
-                    type: object
+                    description: FeatureFlags defines toggle to enable new contour
+                      features. available toggles are useEndpointSlices - configures
+                      contour to fetch endpoint data from k8s endpoint slices. defaults
+                      to false and reading endpoint data from the k8s endpoints.
+                    items:
+                      type: string
+                    type: array
                   gateway:
                     description: Gateway contains parameters for the gateway-api Gateway
                       that Contour is configured to serve traffic.