feat: trace watchable messages (#7403)

* feat: trace watchable messages

Signed-off-by: Shreemaan Abhishek <[email protected]>

Author: shreealt

go.mod

@@ -59,6 +59,7 @@ require (
 	go.opentelemetry.io/otel/metric v1.38.0
 	go.opentelemetry.io/otel/sdk v1.38.0
 	go.opentelemetry.io/otel/sdk/metric v1.38.0
+	go.opentelemetry.io/otel/trace v1.38.0
 	go.opentelemetry.io/proto/otlp v1.9.0
 	go.uber.org/zap v1.27.1
 	golang.org/x/exp v0.0.0-20250718183923-645b1fa84792
@@ -290,7 +291,6 @@ require (
 	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.62.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.37.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.34.0 // indirect
-	go.opentelemetry.io/otel/trace v1.38.0 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
 	go.yaml.in/yaml/v2 v2.4.3 // indirect
 	go.yaml.in/yaml/v3 v3.0.4 // indirect

internal/admin/console/api.go

@@ -260,14 +260,14 @@ func (h *Handler) loadConfigDump() ConfigDumpInfo {
 
 	if h.providerResources != nil {
 		// Load controller resources directly from the provider resources
-		controllerResources := h.providerResources.GatewayAPIResources.LoadAll()
+		controllerResourcesContext := h.providerResources.GatewayAPIResources.LoadAll()
 
-		for _, resources := range controllerResources {
-			if resources == nil {
+		for _, resourcesContext := range controllerResourcesContext {
+			if resourcesContext == nil {
 				continue
 			}
 
-			for _, res := range *resources {
+			for _, res := range *resourcesContext.Resources {
 				if res == nil {
 					continue
 				}

internal/admin/console/api_test.go

@@ -151,7 +151,7 @@ func TestLoadConfigDumpWithData(t *testing.T) {
 	// This test focuses on the basic functionality
 	providerRes := &message.ProviderResources{}
 	// Initialize empty watchable map
-	providerRes.GatewayAPIResources = watchable.Map[string, *resource.ControllerResources]{}
+	providerRes.GatewayAPIResources = watchable.Map[string, *resource.ControllerResourcesContext]{}
 
 	// Skip storing to avoid watchable copy issues
 	// providerResources.Store("test", providerRes)

internal/cmd/server.go

@@ -24,6 +24,7 @@ import (
 	"github.com/envoyproxy/gateway/internal/message"
 	"github.com/envoyproxy/gateway/internal/metrics"
 	providerrunner "github.com/envoyproxy/gateway/internal/provider/runner"
+	"github.com/envoyproxy/gateway/internal/traces"
 	xdsrunner "github.com/envoyproxy/gateway/internal/xds/runner"
 )
 
@@ -171,6 +172,10 @@ func startRunners(ctx context.Context, cfg *config.Server, runnerErrors *message
 	runners := []struct {
 		runner Runner
 	}{
+		{
+			// Start the Traces Server
+			runner: traces.New(cfg),
+		},
 		{
 			// Start the Provider Service
 			// It fetches the resources from the configured provider type

internal/gatewayapi/resource/resource.go

@@ -6,6 +6,8 @@
 package resource
 
 import (
+	"context"
+	"reflect"
 	"sort"
 
 	certificatesv1b1 "k8s.io/api/certificates/v1beta1"
@@ -141,6 +143,47 @@ func (r *Resources) GetEndpointSlicesForBackend(svcNamespace, svcName, backendKi
 // ControllerResources holds all the GatewayAPI resources per GatewayClass
 type ControllerResources []*Resources
 
+// ControllerResourcesContext wraps ControllerResources with trace context
+// for propagating spans across async message boundaries
+type ControllerResourcesContext struct {
+	Resources *ControllerResources
+	Context   context.Context
+}
+
+// DeepCopy creates a new ControllerResourcesContext.
+// The Context field is preserved (not deep copied) since contexts are meant to be passed around.
+func (c *ControllerResourcesContext) DeepCopy() *ControllerResourcesContext {
+	if c == nil {
+		return nil
+	}
+	var resourcesCopy *ControllerResources
+	if c.Resources != nil {
+		resourcesCopy = c.Resources.DeepCopy()
+	}
+	return &ControllerResourcesContext{
+		Resources: resourcesCopy,
+		Context:   c.Context,
+	}
+}
+
+// Equal compares two Resources objects for equality.
+func (c *ControllerResourcesContext) Equal(other *ControllerResourcesContext) bool {
+	if c == nil && other == nil {
+		return true
+	}
+	if c == nil || other == nil {
+		return false
+	}
+	if c.Resources == nil && other.Resources == nil {
+		return true
+	}
+	if c.Resources == nil || other.Resources == nil {
+		return false
+	}
+
+	return reflect.DeepEqual(c.Resources, other.Resources)
+}
+
 // DeepCopy creates a new ControllerResources.
 // It is handwritten since the tooling was unable to copy into a new slice
 func (c *ControllerResources) DeepCopy() *ControllerResources {

internal/gatewayapi/resource/resource_test.go

@@ -6,6 +6,7 @@
 package resource
 
 import (
+	"context"
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
@@ -130,6 +131,38 @@ func TestEqualXds(t *testing.T) {
 	}
 }
 
+func TestEqualControllerResourcesContext(t *testing.T) {
+	c1 := context.Background()
+	c2 := context.TODO()
+	r1 := &ControllerResourcesContext{
+		Resources: &ControllerResources{
+			{
+				GatewayClass: &gwapiv1.GatewayClass{
+					ObjectMeta: metav1.ObjectMeta{
+						Name: "foo",
+					},
+				},
+			},
+		},
+		Context: c1,
+	}
+	r2 := &ControllerResourcesContext{
+		Resources: &ControllerResources{
+			{
+				GatewayClass: &gwapiv1.GatewayClass{
+					ObjectMeta: metav1.ObjectMeta{
+						Name: "foo",
+					},
+				},
+			},
+		},
+		Context: c2,
+	}
+
+	assert.True(t, r1.Equal(r2))
+	assert.True(t, r2.Equal(r1))
+}
+
 func TestGetEndpointSlicesForBackendDualStack(t *testing.T) {
 	// Test data setup
 	dualStackService := &discoveryv1.EndpointSlice{
@@ -205,3 +238,141 @@ func TestGetEndpointSlicesForBackendDualStack(t *testing.T) {
 		}
 	})
 }
+
+func TestControllerResourcesContextDeepCopy(t *testing.T) {
+	tests := []struct {
+		name string
+		ctx  *ControllerResourcesContext
+	}{
+		{
+			name: "nil context",
+			ctx:  nil,
+		},
+		{
+			name: "empty context",
+			ctx: &ControllerResourcesContext{
+				Resources: &ControllerResources{},
+				Context:   context.Background(),
+			},
+		},
+		{
+			name: "context with resources",
+			ctx: &ControllerResourcesContext{
+				Resources: &ControllerResources{
+					{
+						GatewayClass: &gwapiv1.GatewayClass{
+							ObjectMeta: metav1.ObjectMeta{
+								Name: "test-gateway-class",
+							},
+						},
+					},
+				},
+				Context: context.Background(),
+			},
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			copied := tc.ctx.DeepCopy()
+
+			if tc.ctx == nil {
+				assert.Nil(t, copied)
+				return
+			}
+
+			// Verify the copy is not nil
+			require.NotNil(t, copied)
+
+			// Verify the copy is a different object
+			assert.NotSame(t, tc.ctx, copied)
+
+			// Verify Resources are deep copied
+			if tc.ctx.Resources != nil {
+				require.NotNil(t, copied.Resources)
+				assert.NotSame(t, tc.ctx.Resources, copied.Resources)
+
+				// Verify the contents are equal
+				assert.Len(t, *copied.Resources, len(*tc.ctx.Resources))
+			}
+
+			// Verify Context is preserved (not deep copied, same reference)
+			assert.Equal(t, tc.ctx.Context, copied.Context)
+		})
+	}
+}
+
+func TestControllerResourcesDeepCopy(t *testing.T) {
+	tests := []struct {
+		name      string
+		resources *ControllerResources
+	}{
+		{
+			name:      "nil resources",
+			resources: nil,
+		},
+		{
+			name:      "empty resources",
+			resources: &ControllerResources{},
+		},
+		{
+			name: "resources with gateway class",
+			resources: &ControllerResources{
+				{
+					GatewayClass: &gwapiv1.GatewayClass{
+						ObjectMeta: metav1.ObjectMeta{
+							Name: "test-gateway-class",
+						},
+					},
+				},
+			},
+		},
+		{
+			name: "multiple resources",
+			resources: &ControllerResources{
+				{
+					GatewayClass: &gwapiv1.GatewayClass{
+						ObjectMeta: metav1.ObjectMeta{
+							Name: "gateway-class-1",
+						},
+					},
+				},
+				{
+					GatewayClass: &gwapiv1.GatewayClass{
+						ObjectMeta: metav1.ObjectMeta{
+							Name: "gateway-class-2",
+						},
+					},
+				},
+			},
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			copied := tc.resources.DeepCopy()
+
+			if tc.resources == nil {
+				assert.Nil(t, copied)
+				return
+			}
+
+			// Verify the copy is not nil
+			require.NotNil(t, copied)
+
+			// Verify the copy is a different object
+			assert.NotSame(t, tc.resources, copied)
+
+			// Verify the length is the same
+			assert.Len(t, *copied, len(*tc.resources))
+
+			// Verify each resource is deep copied
+			for i := range *tc.resources {
+				if (*tc.resources)[i] != nil {
+					require.NotNil(t, (*copied)[i])
+					assert.NotSame(t, (*tc.resources)[i], (*copied)[i])
+				}
+			}
+		})
+	}
+}