[FAB-9808] override orderers configuration

- Orderers config in endpoint channels config will be
taken into consideration before going through orderers
 in channel configuration.
- This functionality may get removed in future


Change-Id: I67a604f59b616b166a7e7a620ceca43ccb2a2650
Signed-off-by: Sudesh Shetty <sudesh.shetty@securekey.com>

Author: sudeshrshetty

pkg/fab/channel/transactor.go

@@ -16,6 +16,7 @@ import (
 
 	reqContext "context"
 
+	"github.com/hyperledger/fabric-sdk-go/pkg/common/errors/status"
 	contextImpl "github.com/hyperledger/fabric-sdk-go/pkg/context"
 	"github.com/hyperledger/fabric-sdk-go/pkg/core/config/endpoint"
 	"github.com/hyperledger/fabric-sdk-go/pkg/fab/txn"
@@ -54,18 +55,31 @@ func NewTransactor(reqCtx reqContext.Context, cfg fab.ChannelCfg) (*Transactor,
 }
 
 func orderersFromChannelCfg(ctx context.Client, cfg fab.ChannelCfg) ([]fab.Orderer, error) {
-	orderers := []fab.Orderer{}
+
+	//below call to get orderers from endpoint config 'channels.<CHANNEL-ID>.orderers' is not recommended.
+	//To override any orderer configuration items, entity matchers should be used.
+	orderers, err := orderersFromChannel(ctx, cfg.ID())
+	if err != nil {
+		return nil, err
+	}
+	if len(orderers) > 0 {
+		logger.Warn("Getting orderers from endpoint config channels.orderer is deprecated, use entity matchers to override orderer configuration")
+		logger.Warn("visit https://github.com/hyperledger/fabric-sdk-go/blob/master/test/fixtures/config/overrides/local_entity_matchers.yaml for samples")
+		return orderers, nil
+	}
+
 	ordererDict, err := orderersByTarget(ctx)
 	if err != nil {
 		return nil, err
 	}
 
-	// Add orderer if specified in config
+	// Add orderer if specified in channel config
 	for _, target := range cfg.Orderers() {
 
 		// Figure out orderer configuration
 		oCfg, ok := ordererDict[target]
 
+		//try entity matcher
 		if !ok {
 			logger.Debugf("Failed to get channel Cfg orderer [%s] from ordererDict, now trying orderer Matchers in Entity Matchers", target)
 			// Try to find a match from entityMatchers config
@@ -77,6 +91,7 @@ func orderersFromChannelCfg(ctx context.Client, cfg fab.ChannelCfg) ([]fab.Order
 			}
 
 		}
+		//create orderer using channel config block orderer address
 		if !ok {
 			logger.Debugf("Unable to find matching ordererConfig from entity Matchers for channel Cfg Orderer [%s]", target)
 			oCfg = fab.OrdererConfig{
@@ -95,6 +110,39 @@ func orderersFromChannelCfg(ctx context.Client, cfg fab.ChannelCfg) ([]fab.Order
 	return orderers, nil
 }
 
+//deprecated
+//orderersFromChannel returns list of fab.Orderer by channel id
+//will return empty list when orderers are not found in endpoint config
+func orderersFromChannel(ctx context.Client, channelID string) ([]fab.Orderer, error) {
+
+	chNetworkConfig, err := ctx.EndpointConfig().ChannelConfig(channelID)
+	if err != nil {
+		return nil, errors.WithMessage(err, "failed to get channel network config")
+	}
+
+	orderers := []fab.Orderer{}
+	for _, chOrderer := range chNetworkConfig.Orderers {
+
+		ordererConfig, err := ctx.EndpointConfig().OrdererConfig(chOrderer)
+		if err != nil {
+			s, ok := status.FromError(err)
+			if !ok || s.Code != status.NoMatchingOrdererEntity.ToInt32() {
+				return nil, errors.Wrapf(err, "unable to get orderer config from [%s]", chOrderer)
+			}
+			//continue if given channel orderer not found in endpoint config
+			continue
+		}
+
+		orderer, err := ctx.InfraProvider().CreateOrdererFromConfig(ordererConfig)
+		if err != nil {
+			return nil, errors.WithMessage(err, "failed to create orderer from config")
+		}
+
+		orderers = append(orderers, orderer)
+	}
+	return orderers, nil
+}
+
 func orderersByTarget(ctx context.Client) (map[string]fab.OrdererConfig, error) {
 	ordererDict := map[string]fab.OrdererConfig{}
 	orderersConfig, err := ctx.EndpointConfig().OrderersConfig()

pkg/fab/channel/transactor_test.go

@@ -11,8 +11,13 @@ import (
 
 	"time"
 
+	"github.com/hyperledger/fabric-sdk-go/pkg/common/providers/core"
 	"github.com/hyperledger/fabric-sdk-go/pkg/common/providers/fab"
 	"github.com/hyperledger/fabric-sdk-go/pkg/context"
+	"github.com/hyperledger/fabric-sdk-go/pkg/core/config"
+	"github.com/hyperledger/fabric-sdk-go/pkg/core/config/lookup"
+	mocksConfig "github.com/hyperledger/fabric-sdk-go/pkg/core/mocks"
+	fabImpl "github.com/hyperledger/fabric-sdk-go/pkg/fab"
 	"github.com/hyperledger/fabric-sdk-go/pkg/fab/mocks"
 	"github.com/hyperledger/fabric-sdk-go/pkg/fab/txn"
 	mspmocks "github.com/hyperledger/fabric-sdk-go/pkg/msp/test/mockmsp"
@@ -136,3 +141,47 @@ func TestOrderersFromChannelCfgBadTLS(t *testing.T) {
 	assert.Nil(t, err)
 	assert.NotEmpty(t, o)
 }
+
+// TestOrderersURLOverride tests orderer URL override from endpoint channels config
+func TestOrderersURLOverride(t *testing.T) {
+	sampleOrdererURL := "orderer.example.com.sample.url:100090"
+
+	//Create endpoint config
+	configBackends, err := config.FromFile("../../core/config/testdata/config_test.yaml")()
+	if err != nil {
+		t.Fatal("failed to get config backends")
+	}
+
+	//Override orderer URL in endpoint config
+	//Create an empty network config
+	networkConfig := fab.NetworkConfig{}
+	err = lookup.New(configBackends...).UnmarshalKey("orderers", &networkConfig.Orderers)
+	if err != nil {
+		t.Fatal("failed to unmarshal orderer")
+	}
+
+	orderer := networkConfig.Orderers["orderer.example.com"]
+	orderer.URL = sampleOrdererURL
+	networkConfig.Orderers["orderer.example.com"] = orderer
+
+	backendMap := make(map[string]interface{})
+	backendMap["orderers"] = networkConfig.Orderers
+	backends := append([]core.ConfigBackend{}, &mocksConfig.MockConfigBackend{KeyValueMap: backendMap})
+	backends = append(backends, configBackends...)
+	endpointCfg, err := fabImpl.ConfigFromBackend(backends...)
+	if err != nil {
+		t.Fatal("failed to get endpoint config")
+	}
+
+	user := mspmocks.NewMockSigningIdentity("test", "test")
+	ctx := mocks.NewMockContext(user)
+	ctx.SetEndpointConfig(endpointCfg)
+	chConfig := mocks.NewMockChannelCfg("mychannel")
+	chConfig.MockOrderers = []string{"example.com"}
+
+	o, err := orderersFromChannelCfg(ctx, chConfig)
+	assert.Nil(t, err)
+	assert.NotEmpty(t, o)
+	assert.Equal(t, 1, len(o), "expected one orderer from response orderers list")
+	assert.Equal(t, sampleOrdererURL, o[0].URL(), "orderer URL override from endpointconfig channels is not working as expected")
+}

pkg/fab/mocks/mockfabricprovider.go

@@ -69,6 +69,10 @@ func (f *MockInfraProvider) CreateOrdererFromConfig(cfg *fab.OrdererConfig) (fab
 		return f.customOrderer, nil
 	}
 
+	if cfg.URL != "" {
+		return &MockOrderer{OrdererURL: cfg.URL}, nil
+	}
+
 	return &MockOrderer{}, nil
 }