feat: impl cluster buffer limit

internal/gatewayapi/backendtrafficpolicy.go

@@ -301,6 +301,7 @@ func (t *Translator) translateBackendTrafficPolicyForRoute(policy *egv1a1.Backen
 		to        *ir.Timeout
 		ka        *ir.TCPKeepalive
 		rt        *ir.Retry
+		bc        *ir.BackendConnection
 		err, errs error
 	)
 
@@ -348,6 +349,13 @@ func (t *Translator) translateBackendTrafficPolicyForRoute(policy *egv1a1.Backen
 		}
 	}
 
+	if policy.Spec.Connection != nil {
+		if bc, err = t.buildBackendConnection(policy); err != nil {
+			err = perr.WithMessage(err, "BackendConnection")
+			errs = errors.Join(errs, err)
+		}
+	}
+
 	// Early return if got any errors
 	if errs != nil {
 		return errs
@@ -366,17 +374,19 @@ func (t *Translator) translateBackendTrafficPolicyForRoute(policy *egv1a1.Backen
 					r.CircuitBreaker = cb
 					r.TCPKeepalive = ka
 					r.Timeout = to
+					r.BackendConnection = bc
 				}
 			}
 		}
 
 		for _, udp := range x.UDP {
 			if udp.Route != nil {
-				route := udp.Route
+				r := udp.Route
 
-				if strings.HasPrefix(route.Destination.Name, prefix) {
-					route.LoadBalancer = lb
-					route.Timeout = to
+				if strings.HasPrefix(r.Destination.Name, prefix) {
+					r.LoadBalancer = lb
+					r.Timeout = to
+					r.BackendConnection = bc
 				}
 			}
 		}
@@ -386,14 +396,15 @@ func (t *Translator) translateBackendTrafficPolicyForRoute(policy *egv1a1.Backen
 				// Apply if there is a match
 				if strings.HasPrefix(r.Name, prefix) {
 					r.Traffic = &ir.TrafficFeatures{
-						RateLimit:      rl,
-						LoadBalancer:   lb,
-						ProxyProtocol:  pp,
-						HealthCheck:    hc,
-						CircuitBreaker: cb,
-						FaultInjection: fi,
-						TCPKeepalive:   ka,
-						Retry:          rt,
+						RateLimit:         rl,
+						LoadBalancer:      lb,
+						ProxyProtocol:     pp,
+						HealthCheck:       hc,
+						CircuitBreaker:    cb,
+						FaultInjection:    fi,
+						TCPKeepalive:      ka,
+						Retry:             rt,
+						BackendConnection: bc,
 					}
 
 					// Update the Host field in HealthCheck, now that we have access to the Route Hostname.
@@ -1139,6 +1150,31 @@ func int64ToUint32(in int64) (uint32, bool) {
 	return 0, false
 }
 
+func (t *Translator) buildBackendConnection(policy *egv1a1.BackendTrafficPolicy) (*ir.BackendConnection, error) {
+	var (
+		bcIR = &ir.BackendConnection{}
+		bc   = &egv1a1.BackendTrafficPolicyConnection{}
+	)
+
+	if policy.Spec.Connection != nil {
+		bc = policy.Spec.Connection
+
+		if bc.BufferLimit != nil {
+			bf, ok := bc.BufferLimit.AsInt64()
+			if !ok {
+				return nil, fmt.Errorf("invalid BufferLimit value %s", bc.BufferLimit.String())
+			}
+			if bf < 0 || bf > math.MaxUint32 {
+				return nil, fmt.Errorf("BufferLimit value %s is out of range", bc.BufferLimit.String())
+			}
+
+			bcIR.BufferLimitBytes = ptr.To(uint32(bf))
+		}
+	}
+
+	return bcIR, nil
+}
+
 func (t *Translator) buildFaultInjection(policy *egv1a1.BackendTrafficPolicy) *ir.FaultInjection {
 	var fi *ir.FaultInjection
 	if policy.Spec.FaultInjection != nil {

internal/gatewayapi/testdata/backendtrafficpolicy-buffer-limit-out-of-range-error.in.yaml

@@ -0,0 +1,93 @@
+gateways:
+  - apiVersion: gateway.networking.k8s.io/v1
+    kind: Gateway
+    metadata:
+      namespace: envoy-gateway
+      name: gateway-1
+    spec:
+      gatewayClassName: envoy-gateway-class
+      listeners:
+        - name: http
+          protocol: HTTP
+          port: 80
+          allowedRoutes:
+            namespaces:
+              from: All
+  - apiVersion: gateway.networking.k8s.io/v1
+    kind: Gateway
+    metadata:
+      namespace: envoy-gateway
+      name: gateway-2
+    spec:
+      gatewayClassName: envoy-gateway-class
+      listeners:
+        - name: http
+          protocol: HTTP
+          port: 80
+          allowedRoutes:
+            namespaces:
+              from: All
+grpcRoutes:
+  - apiVersion: gateway.networking.k8s.io/v1alpha2
+    kind: GRPCRoute
+    metadata:
+      namespace: default
+      name: grpcroute-1
+    spec:
+      parentRefs:
+        - namespace: envoy-gateway
+          name: gateway-1
+          sectionName: http
+      rules:
+        - backendRefs:
+            - name: service-1
+              port: 8080
+httpRoutes:
+  - apiVersion: gateway.networking.k8s.io/v1
+    kind: HTTPRoute
+    metadata:
+      namespace: default
+      name: httproute-1
+    spec:
+      hostnames:
+        - gateway.envoyproxy.io
+      parentRefs:
+        - namespace: envoy-gateway
+          name: gateway-2
+          sectionName: http
+      rules:
+        - matches:
+            - path:
+                value: "/"
+          backendRefs:
+            - name: service-1
+              port: 8080
+backendTrafficPolicies:
+  - apiVersion: gateway.envoyproxy.io/v1alpha1
+    kind: BackendTrafficPolicy
+    metadata:
+      namespace: envoy-gateway
+      name: policy-for-gateway
+    spec:
+      targetRef:
+        group: gateway.networking.k8s.io
+        kind: Gateway
+        name: gateway-1
+      timeout:
+        tcp:
+          connectTimeout: 15s
+        http:
+          connectionIdleTimeout: 16s
+          maxConnectionDuration: 17s
+  - apiVersion: gateway.envoyproxy.io/v1alpha1
+    kind: BackendTrafficPolicy
+    metadata:
+      namespace: default
+      name: policy-for-route
+    spec:
+      targetRef:
+        group: gateway.networking.k8s.io
+        kind: HTTPRoute
+        name: httproute-1
+      connection:
+        bufferLimit: 1000G