[GEP-1911] h2c backend protocol conformance

conformance/base/manifests.yaml

@@ -91,9 +91,15 @@ spec:
   selector:
     app: infra-backend-v1
   ports:
-  - protocol: TCP
+  - name: first-port
+    protocol: TCP
     port: 8080
     targetPort: 3000
+  - name: second-port
+    protocol: TCP
+    appProtocol: kubernetes.io/h2c
+    port: 8081
+    targetPort: 3001
 ---
 apiVersion: apps/v1
 kind: Deployment

conformance/tests/httproute-backend-protocol-h2c.go

@@ -0,0 +1,66 @@
+/*
+Copyright 2023 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package tests
+
+import (
+	"testing"
+
+	"k8s.io/apimachinery/pkg/types"
+
+	"sigs.k8s.io/gateway-api/conformance/utils/http"
+	"sigs.k8s.io/gateway-api/conformance/utils/kubernetes"
+	"sigs.k8s.io/gateway-api/conformance/utils/roundtripper"
+	"sigs.k8s.io/gateway-api/conformance/utils/suite"
+)
+
+func init() {
+	ConformanceTests = append(ConformanceTests, HTTPRouteBackendProtocolH2C)
+}
+
+var HTTPRouteBackendProtocolH2C = suite.ConformanceTest{
+	ShortName:   "HTTPRouteBackendProtocolH2C",
+	Description: "A HTTPRoute with a BackendRef that has an appProtocol kubernetes.io/h2c should be functional",
+	Features: []suite.SupportedFeature{
+		suite.SupportGateway,
+		suite.SupportHTTPRoute,
+		suite.SupportHTTPRouteBackendProtocolH2C,
+	},
+	Manifests: []string{
+		"tests/httproute-backend-protocol-h2c.yaml",
+	},
+	Test: func(t *testing.T, suite *suite.ConformanceTestSuite) {
+		ns := "gateway-conformance-infra"
+		routeNN := types.NamespacedName{Name: "backend-protocol-h2c", Namespace: ns}
+		gwNN := types.NamespacedName{Name: "same-namespace", Namespace: ns}
+		gwAddr := kubernetes.GatewayAndHTTPRoutesMustBeAccepted(t, suite.Client, suite.TimeoutConfig, suite.ControllerName, kubernetes.NewGatewayRef(gwNN), routeNN)
+
+		// We are not testing the h2c HTTP upgrade mechanism as it is deprecated
+		// See: https://datatracker.ietf.org/doc/html/rfc9113#versioning
+
+		t.Run("http2 prior knowledge request should reach backend", func(t *testing.T) {
+			http.MakeRequestAndExpectEventuallyConsistentResponse(t, suite.RoundTripper, suite.TimeoutConfig, gwAddr, http.ExpectedResponse{
+				Request: http.Request{
+					Path:     "/",
+					Protocol: roundtripper.H2CPriorKnowledgeProtocol,
+				},
+				Response:  http.Response{StatusCode: 200},
+				Backend:   "infra-backend-v1",
+				Namespace: "gateway-conformance-infra",
+			})
+		})
+	},
+}

conformance/tests/httproute-backend-protocol-h2c.yaml

@@ -0,0 +1,17 @@
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  name: backend-protocol-h2c
+  namespace: gateway-conformance-infra
+spec:
+  parentRefs:
+  - name: same-namespace
+  rules:
+  - backendRefs:
+  # This points to a Service with the following ServicePort
+  # - protocol: TCP
+  #   appProtocol: kubernetes.io/h2c
+  #   port: 8081
+  #   targetPort: 3001
+    - name: infra-backend-v1
+      port: 8081

conformance/utils/http/http.go

@@ -116,6 +116,10 @@ func MakeRequest(t *testing.T, expected *ExpectedResponse, gwAddr, protocol, sch
 		expected.Response.StatusCode = 200
 	}
 
+	if expected.Request.Protocol == "" {
+		expected.Request.Protocol = protocol
+	}
+
 	path, query, _ := strings.Cut(expected.Request.Path, "?")
 	reqURL := url.URL{Scheme: scheme, Host: CalculateHost(t, gwAddr, scheme), Path: path, RawQuery: query}
 
@@ -125,7 +129,7 @@ func MakeRequest(t *testing.T, expected *ExpectedResponse, gwAddr, protocol, sch
 		Method:           expected.Request.Method,
 		Host:             expected.Request.Host,
 		URL:              reqURL,
-		Protocol:         protocol,
+		Protocol:         expected.Request.Protocol,
 		Headers:          map[string][]string{},
 		UnfollowRedirect: expected.Request.UnfollowRedirect,
 	}

conformance/utils/roundtripper/roundtripper.go

@@ -21,6 +21,7 @@ import (
 	"crypto/tls"
 	"crypto/x509"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net"
@@ -29,9 +30,15 @@ import (
 	"net/url"
 	"regexp"
 
+	"golang.org/x/net/http2"
+
 	"sigs.k8s.io/gateway-api/conformance/utils/config"
 )
 
+const (
+	H2CPriorKnowledgeProtocol = "H2C_PRIOR_KNOWLEDGE"
+)
+
 // RoundTripper is an interface used to make requests within conformance tests.
 // This can be overridden with custom implementations whenever necessary.
 type RoundTripper interface {
@@ -104,19 +111,7 @@ type DefaultRoundTripper struct {
 	CustomDialContext func(context.Context, string, string) (net.Conn, error)
 }
 
-// CaptureRoundTrip makes a request with the provided parameters and returns the
-// captured request and response from echoserver. An error will be returned if
-// there is an error running the function but not if an HTTP error status code
-// is received.
-func (d *DefaultRoundTripper) CaptureRoundTrip(request Request) (*CapturedRequest, *CapturedResponse, error) {
-	client := &http.Client{}
-
-	if request.UnfollowRedirect {
-		client.CheckRedirect = func(req *http.Request, via []*http.Request) error {
-			return http.ErrUseLastResponse
-		}
-	}
-
+func (d *DefaultRoundTripper) httpTransport(request Request) (http.RoundTripper, error) {
 	transport := &http.Transport{
 		DialContext: d.CustomDialContext,
 		// We disable keep-alives so that we don't leak established TCP connections.
@@ -131,10 +126,61 @@ func (d *DefaultRoundTripper) CaptureRoundTrip(request Request) (*CapturedReques
 	if request.Server != "" && len(request.CertPem) != 0 && len(request.KeyPem) != 0 {
 		tlsConfig, err := tlsClientConfig(request.Server, request.CertPem, request.KeyPem)
 		if err != nil {
-			return nil, nil, err
+			return nil, err
 		}
 		transport.TLSClientConfig = tlsConfig
 	}
+
+	return transport, nil
+}
+
+func (d *DefaultRoundTripper) h2cPriorKnowledgeTransport(request Request) (http.RoundTripper, error) {
+	if request.Server != "" && len(request.CertPem) != 0 && len(request.KeyPem) != 0 {
+		return nil, errors.New("request has configured cert and key but h2 prior knowledge is not encrypted")
+	}
+
+	transport := &http2.Transport{
+		AllowHTTP: true,
+		DialTLSContext: func(ctx context.Context, network, addr string, cfg *tls.Config) (net.Conn, error) {
+			var d net.Dialer
+			return d.DialContext(ctx, network, addr)
+		},
+	}
+
+	return transport, nil
+}
+
+// CaptureRoundTrip makes a request with the provided parameters and returns the
+// captured request and response from echoserver. An error will be returned if
+// there is an error running the function but not if an HTTP error status code
+// is received.
+func (d *DefaultRoundTripper) CaptureRoundTrip(request Request) (*CapturedRequest, *CapturedResponse, error) {
+	var transport http.RoundTripper
+	var err error
+
+	switch request.Protocol {
+	case H2CPriorKnowledgeProtocol:
+		transport, err = d.h2cPriorKnowledgeTransport(request)
+	default:
+		transport, err = d.httpTransport(request)
+	}
+
+	if err != nil {
+		return nil, nil, err
+	}
+
+	return d.defaultRoundTrip(request, transport)
+}
+
+func (d *DefaultRoundTripper) defaultRoundTrip(request Request, transport http.RoundTripper) (*CapturedRequest, *CapturedResponse, error) {
+	client := &http.Client{}
+
+	if request.UnfollowRedirect {
+		client.CheckRedirect = func(req *http.Request, via []*http.Request) error {
+			return http.ErrUseLastResponse
+		}
+	}
+
 	client.Transport = transport
 
 	method := "GET"

conformance/utils/suite/features.go

@@ -133,6 +133,9 @@ const (
 
 	// This option indicates support for HTTPRoute backendRequest timeouts (extended conformance).
 	SupportHTTPRouteBackendTimeout SupportedFeature = "HTTPRouteBackendTimeout"
+
+	// This option indicates support for HTTPRoute with a backendref with an appProtocol 'kubernetes.io/h2c'
+	SupportHTTPRouteBackendProtocolH2C SupportedFeature = "HTTPRouteBackendProtocolH2C"
 )
 
 // HTTPRouteExtendedFeatures includes all the supported features for HTTPRoute
@@ -167,6 +170,7 @@ const (
 // Implementations have the flexibility to opt-in for either specific features or the entire set.
 var HTTPRouteExperimentalFeatures = sets.New(
 	SupportHTTPRouteDestinationPortMatching,
+	SupportHTTPRouteBackendProtocolH2C,
 )
 
 // -----------------------------------------------------------------------------