Async connections to endpoints (#4050) (#4056)

Add the AsyncConnect flag to the grpc connection code for gateway connections to endorsing peers and orderers

Signed-off-by: andrew-coleman <andrew_coleman@uk.ibm.com>
(cherry picked from commit bf9e310)

Co-authored-by: Andrew Coleman <andrew_coleman@uk.ibm.com>

internal/pkg/gateway/endpoint.go

@@ -115,7 +115,8 @@ func (ef *endpointFactory) newConnection(address string, tlsRootCerts [][]byte)
 			Certificate:       ef.clientCert,
 			Key:               ef.clientKey,
 		},
-		DialTimeout: ef.timeout,
+		DialTimeout:  ef.timeout,
+		AsyncConnect: true,
 	}
 	dialOpts, err := config.DialOptions()
 	if err != nil {

internal/pkg/gateway/endpoint_test.go

@@ -6,12 +6,15 @@ SPDX-License-Identifier: Apache-2.0
 package gateway
 
 import (
+	"context"
 	"testing"
 	"time"
 
+	peerprotos "github.com/hyperledger/fabric-protos-go/peer"
 	"github.com/hyperledger/fabric/common/crypto/tlsgen"
 	"github.com/hyperledger/fabric/gossip/common"
 	"github.com/hyperledger/fabric/internal/pkg/comm"
+	"github.com/hyperledger/fabric/internal/pkg/gateway/mocks"
 	"github.com/stretchr/testify/require"
 )
 
@@ -53,3 +56,45 @@ func TestMutualTLS(t *testing.T) {
 	err = endorser.closeConnection()
 	require.NoError(t, err, "failed to close connection")
 }
+
+//go:generate counterfeiter -o mocks/endorserserver.go --fake-name EndorserServer . endorserServer
+type endorserServer interface {
+	peerprotos.EndorserServer
+}
+
+var payload = []byte("test response")
+
+func TestAsyncConnect(t *testing.T) {
+	server, err := comm.NewGRPCServer("127.0.0.1:0", comm.ServerConfig{})
+	require.NoError(t, err)
+
+	endorserServer := &mocks.EndorserServer{}
+	endorserServer.ProcessProposalReturns(&peerprotos.ProposalResponse{Payload: payload}, nil)
+	peerprotos.RegisterEndorserServer(server.Server(), endorserServer)
+
+	factory := &endpointFactory{
+		timeout: 10 * time.Second,
+	}
+
+	endorser, err := factory.newEndorser(common.PKIidType{}, server.Address(), "msp1", nil)
+	require.NoError(t, err, "failed to make async connection to server")
+
+	endorse := func() (*peerprotos.ProposalResponse, error) {
+		ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+		defer cancel()
+		return endorser.client.ProcessProposal(ctx, &peerprotos.SignedProposal{})
+	}
+
+	_, err = endorse() // server not started, so should timeout
+	require.ErrorContains(t, err, "DeadlineExceeded")
+
+	go server.Start()
+	defer server.Stop()
+
+	pr, err := endorse()
+	require.NoError(t, err)
+	require.Equal(t, payload, pr.GetPayload())
+
+	err = endorser.closeConnection()
+	require.NoError(t, err, "failed to close connection")
+}