Add AgentgatewayPolicy frontend tracing support

api/v1alpha1/agentgateway/agentgateway_policy_types.go

@@ -251,7 +251,6 @@ type BackendTLS struct {
 	AlpnProtocols *[]TinyString `json:"alpnProtocols,omitempty"`
 }
 
-// +kubebuilder:validation:XValidation:rule="!has(self.tracing)",message="tracing is not currently implemented"
 type Frontend struct {
 	// tcp defines settings on managing incoming TCP connections.
 	// +optional
@@ -268,7 +267,6 @@ type Frontend struct {
 	AccessLog *AccessLog `json:"accessLog,omitempty"`
 
 	// Tracing contains various settings for OpenTelemetry tracer.
-	// TODO: not currently implemented
 	// +optional
 	Tracing *Tracing `json:"tracing,omitempty"`
 }
@@ -1269,10 +1267,14 @@ type Tracing struct {
 	// +optional
 	Protocol TracingProtocol `json:"protocol,omitempty"`
 
-	// attributes specifies customizations to the key-value pairs that are included in the trace
+	// attributes specify customizations to the key-value pairs that are included in the trace.
 	// +optional
 	Attributes *LogTracingAttributes `json:"attributes,omitempty"`
 
+	// resources describe the entity producing telemetry and specify the resources to be included in the trace.
+	// +optional
+	Resources []ResourceAdd `json:"resources,omitempty"`
+
 	// randomSampling is an expression to determine the amount of random sampling. Random sampling will initiate a new
 	// trace span if the incoming request does not have a trace initiated already. This should evaluate to a float between
 	// 0.0-1.0, or a boolean (true/false) If unspecified, random sampling is disabled.
@@ -1284,3 +1286,10 @@ type Tracing struct {
 	// +optional
 	ClientSampling *shared.CELExpression `json:"clientSampling,omitempty"`
 }
+
+type ResourceAdd struct {
+	// +required
+	Name ShortString `json:"name"`
+	// +required
+	Expression shared.CELExpression `json:"expression"`
+}

go.mod

@@ -461,3 +461,6 @@ tool (
 	sigs.k8s.io/controller-tools/cmd/controller-gen
 	sigs.k8s.io/kind
 )
+
+// TODO: remove and bump agw
+replace github.com/agentgateway/agentgateway => ../agentgateway

go.sum

@@ -91,8 +91,6 @@ github.com/OpenPeeDeeP/depguard/v2 v2.2.1 h1:vckeWVESWp6Qog7UZSARNqfu/cZqvki8zsu
 github.com/OpenPeeDeeP/depguard/v2 v2.2.1/go.mod h1:q4DKzC4UcVaAvcfd41CZh0PWpGgzrVxUYBlgKNGquUo=
 github.com/PuerkitoBio/goquery v1.10.1 h1:Y8JGYUkXWTGRB6Ars3+j3kN0xg1YqqlwvdTV8WTFQcU=
 github.com/PuerkitoBio/goquery v1.10.1/go.mod h1:IYiHrOMps66ag56LEH7QYDDupKXyo5A8qrjIx3ZtujY=
-github.com/agentgateway/agentgateway v0.11.0 h1:+0SDC/YTRJFUtkfFGe3zvxydIEJHGrwVL6pQEThy+yc=
-github.com/agentgateway/agentgateway v0.11.0/go.mod h1:/Lzpteag/nnE4bwW/3Dh5GaxuICmCQs40VhQpkTatlk=
 github.com/alcortesm/tgz v0.0.0-20161220082320-9c5fe88206d7/go.mod h1:6zEj6s6u/ghQa61ZWa/C2Aw3RkjiTBOix7dkqa1VLIs=
 github.com/alecholmes/xfccparser v0.4.0 h1:IFB4bP34oorjcV3n8utZtBhEwlAw9rZ43pb4LgT23Vo=
 github.com/alecholmes/xfccparser v0.4.0/go.mod h1:J9fzzUOtjw74IwNdGVbjnOVj1UDlwGQj1zZzgQRlRDY=

hack/utils/oss_compliance/osa_provided.md

@@ -3,7 +3,7 @@ Name|Version|License
 [cel.dev/expr](https://cel.dev/expr)|v0.25.1|Apache License 2.0
 [semver/v3](https://github.com/Masterminds/semver)|v3.4.0|MIT License
 [PuerkitoBio/goquery](https://github.com/PuerkitoBio/goquery)|v1.10.1|BSD 3-clause "New" or "Revised" License
-[agentgateway/agentgateway](https://github.com/agentgateway/agentgateway)|v0.11.0|Apache License 2.0
+[agentgateway/agentgateway](https://github.com/agentgateway/agentgateway)|latest|Apache License 2.0
 [anthropics/anthropic-sdk-go](https://github.com/anthropics/anthropic-sdk-go)|v1.13.0|MIT License
 [retry-go/v4](https://github.com/avast/retry-go)|v4.7.0|MIT License
 [xds/go](https://github.com/cncf/xds)|v0.0.0-20251110193048-8bfbf64dc13e|Apache License 2.0

install/helm/agentgateway-crds/templates/agentgateway.dev_agentgatewaypolicies.yaml

@@ -1707,8 +1707,8 @@ spec:
                       tracer.
                     properties:
                       attributes:
-                        description: attributes specifies customizations to the key-value
-                          pairs that are included in the trace
+                        description: attributes specify customizations to the key-value
+                          pairs that are included in the trace.
                         properties:
                           add:
                             description: |-
@@ -1844,13 +1844,30 @@ spec:
                         maxLength: 16384
                         minLength: 1
                         type: string
+                      resources:
+                        description: resources describe the entity producing telemetry
+                          and specify the resources to be included in the trace.
+                        items:
+                          properties:
+                            expression:
+                              description: CELExpression represents a Common Expression
+                                Language (CEL) expression.
+                              maxLength: 16384
+                              minLength: 1
+                              type: string
+                            name:
+                              maxLength: 256
+                              minLength: 1
+                              type: string
+                          required:
+                          - expression
+                          - name
+                          type: object
+                        type: array
                     required:
                     - backendRef
                     type: object
                 type: object
-                x-kubernetes-validations:
-                - message: tracing is not currently implemented
-                  rule: '!has(self.tracing)'
               targetRefs:
                 description: targetRefs specifies the target resources by reference
                   to attach the policy to.

pkg/agentgateway/plugins/frontend_policies.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/kgateway-dev/kgateway/v2/api/v1alpha1/agentgateway"
 	"github.com/kgateway-dev/kgateway/v2/pkg/kgateway/wellknown"
+	"github.com/kgateway-dev/kgateway/v2/pkg/utils/kubeutils"
 )
 
 const (
@@ -63,18 +64,95 @@ func translateFrontendPolicyToAgw(
 
 func translateFrontendTracing(policy *agentgateway.AgentgatewayPolicy, name string, target *api.PolicyTarget) []AgwPolicy {
 	tracing := policy.Spec.Frontend.Tracing
+	if tracing == nil {
+		return nil
+	}
+
+	var provider *api.BackendReference
+	ref := tracing.BackendRef
+	if ref.Kind == nil || *ref.Kind == "Service" {
+		ns := policy.GetNamespace()
+		if tracing.BackendRef.Namespace != nil {
+			ns = string(*tracing.BackendRef.Namespace)
+		}
+		var port uint32
+		if ref.Port != nil {
+			port = uint32(*ref.Port)
+		}
+		hostname := kubeutils.GetServiceHostname(string(ref.Name), ns)
+		provider = &api.BackendReference{
+			Kind: &api.BackendReference_Service_{
+				Service: &api.BackendReference_Service{
+					Namespace: ns,
+					Hostname:  hostname,
+				},
+			},
+			Port: port,
+		}
+	} else {
+		// TODO: support other backend ref kinds
+		logger.Error("Backend reference kind is not supported", "kind", string(*ref.Kind))
+	}
+
+	var addAttributes []*api.FrontendPolicySpec_TracingAttribute
+	var rmAttributes []string
+	if tracing.Attributes != nil {
+		for _, add := range tracing.Attributes.Add {
+			addAttributes = append(addAttributes, &api.FrontendPolicySpec_TracingAttribute{
+				Name:  add.Name,
+				Value: string(add.Expression),
+			})
+		}
+		for _, rm := range tracing.Attributes.Remove {
+			rmAttributes = append(rmAttributes, rm)
+		}
+	}
+
+	var addResources []*api.FrontendPolicySpec_TracingAttribute
+	if tracing.Resources != nil {
+		for _, add := range tracing.Resources {
+			addResources = append(addResources, &api.FrontendPolicySpec_TracingAttribute{
+				Name:  add.Name,
+				Value: string(add.Expression),
+			})
+		}
+	}
+
+	var randomSampling *string
+	if tracing.RandomSampling != nil {
+		randomSampling = ptr.Of(string(*tracing.RandomSampling))
+	}
+
+	var clientSampling *string
+	if tracing.ClientSampling != nil {
+		clientSampling = ptr.Of(string(*tracing.ClientSampling))
+	}
+
+	protocol := api.FrontendPolicySpec_Tracing_HTTP
+	if tracing.Protocol == agentgateway.TracingProtocolHttp {
+		protocol = api.FrontendPolicySpec_Tracing_HTTP
+	} else if tracing.Protocol == agentgateway.TracingProtocolGrpc {
+		protocol = api.FrontendPolicySpec_Tracing_GRPC
+	}
+
 	tracingPolicy := &api.Policy{
 		Key:    name + frontendTracingPolicySuffix + attachmentName(target),
 		Name:   TypedResourceName(wellknown.AgentgatewayPolicyGVK.Kind, policy),
 		Target: target,
 		Kind: &api.Policy_Frontend{
 			Frontend: &api.FrontendPolicySpec{
-				// TODO: implement this
-				Kind: &api.FrontendPolicySpec_Tracing_{Tracing: &api.FrontendPolicySpec_Tracing{}},
+				Kind: &api.FrontendPolicySpec_Tracing_{Tracing: &api.FrontendPolicySpec_Tracing{
+					ProviderBackend: provider,
+					Attributes:      addAttributes,
+					Remove:          rmAttributes,
+					Resources:       addResources,
+					Protocol:        protocol,
+					RandomSampling:  randomSampling,
+					ClientSampling:  clientSampling,
+				}},
 			},
 		},
 	}
-	_ = tracing
 
 	logger.Debug("generated tracing policy",
 		"policy", policy.Name,

pkg/agentgateway/plugins/testdata/frontendpolicy/full.yaml

@@ -29,19 +29,23 @@ spec:
         add:
           - expression: 'request.headers["user-agent"]'
             name: http.useragent
-#    tracing:
-#      backendRef:
-#        name: my-otel
-#        namespace: some-other-ns
-#      protocol: GRPC
-#      clientSampling: "true"
-#      randomSampling: "true"
-#      attributes:
-#        remove:
-#          - response.code
-#        add:
-#          - expression: 'request.headers["user-agent"]'
-#            name: http.useragent
+    tracing:
+      backendRef:
+        name: my-otel
+        namespace: some-other-ns
+        port: 4317
+      protocol: GRPC
+      clientSampling: "true"
+      randomSampling: "true"
+      resources:
+        - name: service.name
+          expression: "agent-gateway"
+      attributes:
+        remove:
+          - response.code
+        add:
+          - expression: 'request.headers["user-agent"]'
+            name: http.useragent
 
 ---
 # Output
@@ -111,6 +115,34 @@ output:
       gateway:
         name: test
         namespace: default
+- Policy:
+    frontend:
+      tracing:
+        attributes:
+        - name: http.useragent
+          value: request.headers["user-agent"]
+        clientSampling: "true"
+        protocol: GRPC
+        providerBackend:
+          port: 4317
+          service:
+            hostname: my-otel.some-other-ns.svc.cluster.local
+            namespace: some-other-ns
+        randomSampling: "true"
+        remove:
+        - response.code
+        resources:
+        - name: service.name
+          value: agent-gateway
+    key: frontend/default/agw:frontend-tracing:default/test
+    name:
+      kind: AgentgatewayPolicy
+      name: agw
+      namespace: default
+    target:
+      gateway:
+        name: test
+        namespace: default
 status:
   ancestors:
   - ancestorRef:

test/e2e/features/tracing/testdata/setup.yaml

@@ -62,53 +62,4 @@ spec:
               cpu: "100m"
             limits:
               cpu: "200m"
----
-# Custom GWP to define OTEL_RESOURCE_ATTRIBUTES required for the environment detector
-kind: GatewayParameters
-apiVersion: gateway.kgateway.dev/v1alpha1
-metadata:
-  name: tracing-params
-spec:
-  kube:
-    envoyContainer:
-      env:
-      - name: OTEL_RESOURCE_ATTRIBUTES
-        value: "environment=detector,resource=attribute"
----
-kind: Gateway
-apiVersion: gateway.networking.k8s.io/v1
-metadata:
-  name: gw
-spec:
-  gatewayClassName: kgateway
-  infrastructure:
-    parametersRef:
-      name: tracing-params
-      group: gateway.kgateway.dev
-      kind: GatewayParameters
-  listeners:
-    - protocol: HTTP
-      port: 8080
-      name: http
-      allowedRoutes:
-        namespaces:
-          from: All
----
-apiVersion: gateway.networking.k8s.io/v1
-kind: HTTPRoute
-metadata:
-  name: httpbin
-  namespace: httpbin
-  labels:
-    example: httpbin-route
-spec:
-  parentRefs:
-    - name: gw
-      namespace: default
-  hostnames:
-    - "www.example.com"
-  rules:
-    - backendRefs:
-        - name: httpbin
-          port: 8000
 ---