feat: Direct Response

api/v1alpha1/virtualbackend_types.go

@@ -0,0 +1,52 @@
+// Copyright Envoy Gateway Authors
+// SPDX-License-Identifier: Apache-2.0
+// The full text of the Apache license is available in the LICENSE file at
+// the root of the repo.
+
+package v1alpha1
+
+import metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+
+const (
+	// KindVirtualBackend is the name of the VirtualBackend kind.
+	KindVirtualBackend = "VirtualBackend"
+)
+
+// +kubebuilder:validation:Minimum=100
+// +kubebuilder:validation:Maximum=599
+type StatusCode uint32
+
+// +kubebuilder:validation:Pattern=`^([\w-]+)$`
+type ResponseHeader string
+
+// +kubebuilder:object:root=true
+// +kubebuilder:resource:categories=envoy-gateway,shortName=vb
+//
+// VirtualBackend defines the configuration for direct response.
+type VirtualBackend struct {
+	metav1.TypeMeta   `json:",inline"`
+	metav1.ObjectMeta `json:"metadata,omitempty"`
+
+	// Spec defines desired state of VirtualBackend.
+	Spec VirtualBackendSpec `json:"spec"`
+}
+
+// +kubebuilder:validation:XValidation:rule="has(self.statusCode)"
+//
+// VirtualBackendSpec defines direct response configuration.
+type VirtualBackendSpec struct {
+	// +optional
+	//
+	// Body contains data which gateway returns in direct response.
+	Body *[]byte `json:"body,omitempty" yaml:"body,omitempty"`
+
+	// +kubebuilder:default=200
+	//
+	// StatusCode defines HTTP response status code of direct response. Default value is 200.
+	StatusCode StatusCode `json:"statusCode" yaml:"statusCode"`
+
+	// +optional
+	//
+	// ResponseHeaders defines Header:Value map of additional headers to response.
+	ResponseHeaders map[ResponseHeader]string `json:"responseHeaders,omitempty" yaml:"responseHeaders,omitempty"`
+}

charts/gateway-helm/crds/generated/gateway.envoyproxy.io_virtualbackends.yaml

@@ -0,0 +1,73 @@
+---
+apiVersion: apiextensions.k8s.io/v1
+kind: CustomResourceDefinition
+metadata:
+  annotations:
+    controller-gen.kubebuilder.io/version: v0.15.0
+  name: virtualbackends.gateway.envoyproxy.io
+spec:
+  group: gateway.envoyproxy.io
+  names:
+    categories:
+    - envoy-gateway
+    kind: VirtualBackend
+    listKind: VirtualBackendList
+    plural: virtualbackends
+    shortNames:
+    - vb
+    singular: virtualbackend
+  scope: Namespaced
+  versions:
+  - name: v1alpha1
+    schema:
+      openAPIV3Schema:
+        description: VirtualBackend defines the configuration for direct response.
+        properties:
+          apiVersion:
+            description: |-
+              APIVersion defines the versioned schema of this representation of an object.
+              Servers should convert recognized schemas to the latest internal value, and
+              may reject unrecognized values.
+              More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources
+            type: string
+          kind:
+            description: |-
+              Kind is a string value representing the REST resource this object represents.
+              Servers may infer this from the endpoint the client submits requests to.
+              Cannot be updated.
+              In CamelCase.
+              More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds
+            type: string
+          metadata:
+            type: object
+          spec:
+            description: Spec defines desired state of VirtualBackend.
+            properties:
+              body:
+                description: Body contains data which gateway returns in direct response.
+                format: byte
+                type: string
+              responseHeaders:
+                additionalProperties:
+                  type: string
+                description: ResponseHeaders defines Header:Value map of additional
+                  headers to response.
+                type: object
+              statusCode:
+                default: 200
+                description: StatusCode defines HTTP response status code of direct
+                  response. Default value is 200.
+                format: int32
+                maximum: 599
+                minimum: 100
+                type: integer
+            required:
+            - statusCode
+            type: object
+            x-kubernetes-validations:
+            - rule: has(self.statusCode)
+        required:
+        - spec
+        type: object
+    served: true
+    storage: true

internal/gatewayapi/resource.go

@@ -63,6 +63,7 @@ type Resources struct {
 	EnvoyExtensionPolicies  []*egv1a1.EnvoyExtensionPolicy `json:"envoyExtensionPolicies,omitempty" yaml:"envoyExtensionPolicies,omitempty"`
 	ExtensionServerPolicies []unstructured.Unstructured    `json:"extensionServerPolicies,omitempty" yaml:"extensionServerPolicies,omitempty"`
 	Backends                []*egv1a1.Backend              `json:"backends,omitempty" yaml:"backends,omitempty"`
+	VirtualBackends         []*egv1a1.VirtualBackend       `json:"virtualBackends,omitempty" yaml:"virtualBackends,omitempty"`
 }
 
 func NewResources() *Resources {
@@ -86,6 +87,7 @@ func NewResources() *Resources {
 		EnvoyExtensionPolicies:  []*egv1a1.EnvoyExtensionPolicy{},
 		ExtensionServerPolicies: []unstructured.Unstructured{},
 		Backends:                []*egv1a1.Backend{},
+		VirtualBackends:         []*egv1a1.VirtualBackend{},
 	}
 }
 
@@ -139,6 +141,16 @@ func (r *Resources) GetBackend(namespace, name string) *egv1a1.Backend {
 	return nil
 }
 
+func (r *Resources) GetVirtualBackend(namespace, name string) *egv1a1.VirtualBackend {
+	for _, vb := range r.VirtualBackends {
+		if vb.Namespace == namespace && vb.Name == name {
+			return vb
+		}
+	}
+
+	return nil
+}
+
 func (r *Resources) GetSecret(namespace, name string) *corev1.Secret {
 	for _, secret := range r.Secrets {
 		if secret.Namespace == namespace && secret.Name == name {

internal/gatewayapi/route.go

@@ -202,6 +202,27 @@ func (t *Translator) processHTTPRouteRules(httpRoute *HTTPRouteContext, parentRe
 			if !t.IsEnvoyServiceRouting(envoyProxy) && ds != nil && len(ds.Endpoints) > 0 && ds.AddressType != nil {
 				dstAddrTypeMap[*ds.AddressType]++
 			}
+
+			if backendRef.Kind != nil && *backendRef.Kind == egv1a1.KindVirtualBackend {
+				vb := resources.GetVirtualBackend(NamespaceDerefOr(backendRef.Namespace, httpRoute.Namespace), string(backendRef.Name))
+				for _, route := range ruleRoutes {
+					directResponse := &ir.DirectResponse{
+						Body:       string(*vb.Spec.Body),
+						StatusCode: uint32(vb.Spec.StatusCode),
+					}
+
+					route.DirectResponse = directResponse
+					for header, value := range vb.Spec.ResponseHeaders {
+						responseHeader := ir.AddHeader{
+							Name:   string(header),
+							Value:  value,
+							Append: false,
+						}
+						route.AddResponseHeaders = append(route.AddResponseHeaders, responseHeader)
+					}
+				}
+			}
+
 			if ds == nil {
 				continue
 			}
@@ -237,7 +258,7 @@ func (t *Translator) processHTTPRouteRules(httpRoute *HTTPRouteContext, parentRe
 		// If the route has no valid backends then just use a direct response and don't fuss with weighted responses
 		for _, ruleRoute := range ruleRoutes {
 			noValidBackends := ruleRoute.Destination == nil || ruleRoute.Destination.ToBackendWeights().Valid == 0
-			if noValidBackends && ruleRoute.Redirect == nil {
+			if noValidBackends && ruleRoute.Redirect == nil && ruleRoute.DirectResponse == nil {
 				ruleRoute.DirectResponse = &ir.DirectResponse{
 					StatusCode: 500,
 				}

internal/gatewayapi/testdata/httproute-with-virtualbackend.in.yaml

@@ -0,0 +1,45 @@
+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
+          hostname: "*.envoyproxy.io"
+          allowedRoutes:
+            namespaces:
+              from: All
+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-1
+          sectionName: http
+      rules:
+        - matches:
+            - path:
+                value: "/"
+          backendRefs:
+            - kind: VirtualBackend
+              name: virtual-backend-1
+virtualBackends:
+  - apiVersion: gateway.envoyproxy.io/v1alpha1
+    kind: VirtualBackend
+    metadata:
+      namespace: default
+      name: virtual-backend-1
+    spec:
+      body: eyJlcnIiOiAiU29tZSBlcnJvciJ9
+      statusCode: 501