expose GRPC conformance client as in interface

conformance/tests/grpcroute-exact-method-matching.go

@@ -69,7 +69,7 @@ var GRPCExactMethodMatching = suite.ConformanceTest{
 			tc := testCases[i]
 			t.Run(tc.GetTestCaseName(i), func(t *testing.T) {
 				t.Parallel()
-				grpc.MakeRequestAndExpectEventuallyConsistentResponse(t, suite.TimeoutConfig, gwAddr, tc)
+				grpc.MakeRequestAndExpectEventuallyConsistentResponse(t, suite.GRPCClient, suite.TimeoutConfig, gwAddr, tc)
 			})
 		}
 	},

conformance/tests/grpcroute-header-matching.go

@@ -130,7 +130,7 @@ var GRPCRouteHeaderMatching = suite.ConformanceTest{
 			tc := testCases[i]
 			t.Run(tc.GetTestCaseName(i), func(t *testing.T) {
 				t.Parallel()
-				grpc.MakeRequestAndExpectEventuallyConsistentResponse(t, suite.TimeoutConfig, gwAddr, tc)
+				grpc.MakeRequestAndExpectEventuallyConsistentResponse(t, suite.GRPCClient, suite.TimeoutConfig, gwAddr, tc)
 			})
 		}
 	},

conformance/tests/grpcroute-listener-hostname-matching.go

@@ -126,7 +126,7 @@ var GRPCRouteListenerHostnameMatching = suite.ConformanceTest{
 			tc := testCases[i]
 			t.Run(tc.GetTestCaseName(i), func(t *testing.T) {
 				t.Parallel()
-				grpc.MakeRequestAndExpectEventuallyConsistentResponse(t, suite.TimeoutConfig, gwAddr, tc)
+				grpc.MakeRequestAndExpectEventuallyConsistentResponse(t, suite.GRPCClient, suite.TimeoutConfig, gwAddr, tc)
 			})
 		}
 	},

conformance/utils/grpc/grpc.go

@@ -42,6 +42,19 @@ const (
 	echoServerService = "GrpcEcho"
 )
 
+// Client is an interface used to make requests within conformance tests for grpc scenarios.
+// This can be overridden with custom implementations whenever necessary.
+type Client interface {
+	SendRPC(t *testing.T, address string, expected ExpectedResponse, timeout time.Duration) (*Response, error)
+	Close()
+}
+
+// DefaultClient is the default implementation of Client. It will
+// be used if a custom implementation is not specified.
+type DefaultClient struct {
+	Conn *grpc.ClientConn
+}
+
 type Response struct {
 	Code     codes.Code
 	Headers  *metadata.MD
@@ -136,19 +149,14 @@ func (er *ExpectedResponse) GetTestCaseName(i int) string {
 	return fmt.Sprintf("%s should receive a %s (%d)", reqStr, er.Response.Code.String(), er.Response.Code)
 }
 
-type client struct {
-	Conn            *grpc.ClientConn
-	RequestMetadata *RequestMetadata
-}
-
-func (c *client) ensureConnection(address string) error {
+func (c *DefaultClient) ensureConnection(address string, req *RequestMetadata) error {
 	if c.Conn != nil {
 		return nil
 	}
 	var err error
 	dialOpts := []grpc.DialOption{grpc.WithTransportCredentials(insecure.NewCredentials())}
-	if c.RequestMetadata != nil && c.RequestMetadata.Authority != "" {
-		dialOpts = append(dialOpts, grpc.WithAuthority(c.RequestMetadata.Authority))
+	if req != nil && req.Authority != "" {
+		dialOpts = append(dialOpts, grpc.WithAuthority(req.Authority))
 	}
 
 	c.Conn, err = grpc.Dial(address, dialOpts...)
@@ -159,17 +167,20 @@ func (c *client) ensureConnection(address string) error {
 	return nil
 }
 
-func (c *client) resetConnection() {
+func (c *DefaultClient) resetConnection() {
 	if c.Conn == nil {
 		return
 	}
 	c.Conn.Close()
 	c.Conn = nil
 }
 
-func (c *client) SendRPC(t *testing.T, address string, expected ExpectedResponse, timeout time.Duration) (*Response, error) {
+// SendRPC sends a gRPC request to the given address with the expected response.
+// An error will be returned if there is an error running the function but not if an HTTP error status code
+// is received.
+func (c *DefaultClient) SendRPC(t *testing.T, address string, expected ExpectedResponse, timeout time.Duration) (*Response, error) {
 	t.Helper()
-	if err := c.ensureConnection(address); err != nil {
+	if err := c.ensureConnection(address, expected.RequestMetadata); err != nil {
 		return &Response{}, err
 	}
 
@@ -179,8 +190,8 @@ func (c *client) SendRPC(t *testing.T, address string, expected ExpectedResponse
 	}
 	ctx, cancel := context.WithTimeout(context.Background(), timeout)
 
-	if c.RequestMetadata != nil && len(c.RequestMetadata.Metadata) > 0 {
-		ctx = metadata.NewOutgoingContext(ctx, metadata.New(c.RequestMetadata.Metadata))
+	if expected.RequestMetadata != nil && len(expected.RequestMetadata.Metadata) > 0 {
+		ctx = metadata.NewOutgoingContext(ctx, metadata.New(expected.RequestMetadata.Metadata))
 	}
 
 	defer cancel()
@@ -215,7 +226,7 @@ func (c *client) SendRPC(t *testing.T, address string, expected ExpectedResponse
 	return resp, nil
 }
 
-func (c *client) Close() {
+func (c *DefaultClient) Close() {
 	if c.Conn != nil {
 		c.Conn.Close()
 	}
@@ -256,13 +267,9 @@ func validateExpectedResponse(t *testing.T, expected ExpectedResponse) {
 	require.Equal(t, 1, requestTypeCount, "expected only one request type to be set, but found %d: %v", requestTypeCount, expected)
 }
 
-func MakeRequestAndExpectEventuallyConsistentResponse(t *testing.T, timeoutConfig config.TimeoutConfig, gwAddr string, expected ExpectedResponse) {
+func MakeRequestAndExpectEventuallyConsistentResponse(t *testing.T, c Client, timeoutConfig config.TimeoutConfig, gwAddr string, expected ExpectedResponse) {
 	t.Helper()
 	validateExpectedResponse(t, expected)
-	c := &client{
-		Conn:            nil,
-		RequestMetadata: expected.RequestMetadata,
-	}
 	defer c.Close()
 	sendRPC := func(elapsed time.Duration) bool {
 		resp, err := c.SendRPC(t, gwAddr, expected, timeoutConfig.MaxTimeToConsistency-elapsed)

conformance/utils/suite/suite.go

@@ -40,6 +40,7 @@ import (
 	confv1 "sigs.k8s.io/gateway-api/conformance/apis/v1"
 	"sigs.k8s.io/gateway-api/conformance/utils/config"
 	"sigs.k8s.io/gateway-api/conformance/utils/flags"
+	"sigs.k8s.io/gateway-api/conformance/utils/grpc"
 	"sigs.k8s.io/gateway-api/conformance/utils/kubernetes"
 	"sigs.k8s.io/gateway-api/conformance/utils/roundtripper"
 	"sigs.k8s.io/gateway-api/conformance/utils/tlog"
@@ -59,6 +60,7 @@ type ConformanceTestSuite struct {
 	RESTClient               *rest.RESTClient
 	RestConfig               *rest.Config
 	RoundTripper             roundtripper.RoundTripper
+	GRPCClient               grpc.Client
 	GatewayClassName         string
 	ControllerName           string
 	Debug                    bool
@@ -125,6 +127,7 @@ type ConformanceOptions struct {
 	GatewayClassName     string
 	Debug                bool
 	RoundTripper         roundtripper.RoundTripper
+	GRPCClient           grpc.Client
 	BaseManifests        string
 	MeshManifests        string
 	NamespaceLabels      map[string]string
@@ -189,6 +192,11 @@ func NewConformanceTestSuite(options ConformanceOptions) (*ConformanceTestSuite,
 		roundTripper = &roundtripper.DefaultRoundTripper{Debug: options.Debug, TimeoutConfig: options.TimeoutConfig}
 	}
 
+	grpcClient := options.GRPCClient
+	if grpcClient == nil {
+		grpcClient = &grpc.DefaultClient{Conn: nil}
+	}
+
 	installedCRDs := &apiextensionsv1.CustomResourceDefinitionList{}
 	err := options.Client.List(context.TODO(), installedCRDs)
 	if err != nil {
@@ -229,6 +237,7 @@ func NewConformanceTestSuite(options ConformanceOptions) (*ConformanceTestSuite,
 		Clientset:        options.Clientset,
 		RestConfig:       options.RestConfig,
 		RoundTripper:     roundTripper,
+		GRPCClient:       grpcClient,
 		GatewayClassName: options.GatewayClassName,
 		Debug:            options.Debug,
 		Cleanup:          options.CleanupBaseResources,