Evaluate() error response for node chaincode

The gateway Evaluate() method is not returning the error response to the client for node chaincodes. The code path for node chaincode errors is different than for Go chaincodes (this is a known separate issue).
It turns out the endorser is handling this difference and populates the Response field of the ProposalResponse accordingly.  The gateway needs to use this field rather than the one in the ChaincodeAction structure.

Signed-off-by: andrew-coleman <andrew_coleman@uk.ibm.com>

internal/pkg/gateway/api.go

@@ -66,20 +66,22 @@ func (gs *Server) Evaluate(ctx context.Context, request *gp.EvaluateRequest) (*g
 
 	response, err := endorser.client.ProcessProposal(ctx, signedProposal)
 	if err != nil {
-		logger.Debugw("Evaluate call to endorser failed", "channel", request.ChannelId, "txid", request.TransactionId, "endorserAddress", endorser.endpointConfig.address, "endorserMspid", endorser.endpointConfig.mspid, "error", err)
+		logger.Debugw("Evaluate call to endorser failed", "chaincode", chaincodeID, "channel", channel, "txid", request.TransactionId, "endorserAddress", endorser.endpointConfig.address, "endorserMspid", endorser.endpointConfig.mspid, "error", err)
 		return nil, wrappedRpcError(err, "failed to evaluate transaction", endpointError(endorser.endpointConfig, err))
 	}
 
-	retVal, err := getTransactionResponse(response)
-	if err != nil {
-		logger.Debugw("Evaluate call to endorser returned a malformed or error response", "channel", request.ChannelId, "txid", request.TransactionId, "endorserAddress", endorser.endpointConfig.address, "endorserMspid", endorser.endpointConfig.mspid, "error", err)
-		return nil, rpcError(codes.Unknown, err.Error(), endpointError(endorser.endpointConfig, err))
+	rr := response.GetResponse()
+	if rr != nil && (rr.Status < 200 || rr.Status >= 400) {
+		logger.Debugw("Evaluate call to endorser returned a malformed or error response", "chaincode", chaincodeID, "channel", channel, "txid", request.TransactionId, "endorserAddress", endorser.endpointConfig.address, "endorserMspid", endorser.endpointConfig.mspid, "status", rr.Status, "message", rr.Message)
+		err = fmt.Errorf("error %d returned from chaincode %s on channel %s: %s", rr.Status, chaincodeID, channel, rr.Message)
+		return nil, rpcError(codes.Unknown, "error returned from chaincode: "+rr.Message, endpointError(endorser.endpointConfig, err))
 	}
+
 	evaluateResponse := &gp.EvaluateResponse{
-		Result: retVal,
+		Result: rr,
 	}
 
-	logger.Debugw("Evaluate call to endorser returned success", "channel", request.ChannelId, "txid", request.TransactionId, "endorserAddress", endorser.endpointConfig.address, "endorserMspid", endorser.endpointConfig.mspid, "status", retVal.GetStatus(), "message", retVal.GetMessage())
+	logger.Debugw("Evaluate call to endorser returned success", "channel", request.ChannelId, "txid", request.TransactionId, "endorserAddress", endorser.endpointConfig.address, "endorserMspid", endorser.endpointConfig.mspid, "status", rr.GetStatus(), "message", rr.GetMessage())
 	return evaluateResponse, nil
 }
 
@@ -247,13 +249,8 @@ func (gs *Server) Endorse(ctx context.Context, request *gp.EndorseRequest) (*gp.
 		return nil, status.Errorf(codes.Aborted, "failed to assemble transaction: %s", err)
 	}
 
-	retVal, err := getTransactionResponse(responses[0])
-	if err != nil {
-		return nil, status.Errorf(codes.Aborted, "failed to extract transaction response: %s", err)
-	}
-
 	endorseResponse := &gp.EndorseResponse{
-		Result:              retVal,
+		Result:              responses[0].GetResponse(),
 		PreparedTransaction: env,
 	}
 	return endorseResponse, nil

internal/pkg/gateway/api_test.go

@@ -309,11 +309,11 @@ func TestEvaluate(t *testing.T) {
 				proposalResponseStatus:  400,
 				proposalResponseMessage: "Mock chaincode error",
 			},
-			errString: "rpc error: code = Unknown desc = error 400, Mock chaincode error",
+			errString: "rpc error: code = Unknown desc = error returned from chaincode: Mock chaincode error",
 			errDetails: []*pb.EndpointError{{
 				Address: "peer1:8051",
 				MspId:   "msp1",
-				Message: "error 400, Mock chaincode error",
+				Message: "error 400 returned from chaincode test_chaincode on channel test_channel: Mock chaincode error",
 			}},
 		},
 		{

internal/pkg/gateway/apiutils.go

@@ -17,31 +17,6 @@ import (
 	"google.golang.org/grpc/status"
 )
 
-func getTransactionResponse(response *peer.ProposalResponse) (*peer.Response, error) {
-	var retVal *peer.Response
-
-	if response.GetPayload() != nil {
-		payload, err := protoutil.UnmarshalProposalResponsePayload(response.Payload)
-		if err != nil {
-			return nil, err
-		}
-
-		extension, err := protoutil.UnmarshalChaincodeAction(payload.Extension)
-		if err != nil {
-			return nil, err
-		}
-
-		if extension.GetResponse() != nil {
-			if extension.Response.Status < 200 || extension.Response.Status >= 400 {
-				return nil, fmt.Errorf("error %d, %s", extension.Response.Status, extension.Response.Message)
-			}
-			retVal = extension.Response
-		}
-	}
-
-	return retVal, nil
-}
-
 func getChannelAndChaincodeFromSignedProposal(signedProposal *peer.SignedProposal) (string, string, bool, error) {
 	if signedProposal == nil {
 		return "", "", false, fmt.Errorf("a signed proposal is required")