FAB-8591 Improve channel create/update error

This CR simply wraps the output returned from the configtx processing to
indicate whether the update processing was being treated as channel
creation, or as a channel update.  This is to assist users especially
when they attempt to recreate an extant channel resulting in a
previously difficult to understand error message.

Change-Id: I39d0adc0a4b9b53aa252710575e83309f5fa4524
Signed-off-by: Jason Yellick <jyellick@us.ibm.com>

common/configtx/update.go

@@ -22,7 +22,7 @@ func (vi *ValidatorImpl) verifyReadSet(readSet map[string]comparable) error {
 		}
 
 		if existing.version() != value.version() {
-			return errors.Errorf("readset expected key %s at version %d, but got version %d", key, value.version(), existing.version())
+			return errors.Errorf("proposed update requires that key %s be at version %d, but it is currently at version %d", key, value.version(), existing.version())
 		}
 	}
 	return nil

orderer/common/msgprocessor/standardchannel.go

@@ -7,11 +7,15 @@ SPDX-License-Identifier: Apache-2.0
 package msgprocessor
 
 import (
+	"fmt"
+
 	"github.com/hyperledger/fabric/common/channelconfig"
 	"github.com/hyperledger/fabric/common/crypto"
 	"github.com/hyperledger/fabric/common/policies"
 	cb "github.com/hyperledger/fabric/protos/common"
 	"github.com/hyperledger/fabric/protos/utils"
+
+	"github.com/pkg/errors"
 )
 
 // StandardChannelSupport includes the resources needed for the StandardChannel processor.
@@ -98,7 +102,7 @@ func (s *StandardChannel) ProcessConfigUpdateMsg(env *cb.Envelope) (config *cb.E
 
 	configEnvelope, err := s.support.ProposeConfigUpdate(env)
 	if err != nil {
-		return nil, 0, err
+		return nil, 0, errors.WithMessage(err, fmt.Sprintf("error applying config update to existing channel '%s'", s.support.ChainID()))
 	}
 
 	config, err = utils.CreateSignedEnvelope(cb.HeaderType_CONFIG, s.support.ChainID(), s.support.Signer(), configEnvelope, msgVersion, epoch)

orderer/common/msgprocessor/standardchannel_test.go

@@ -69,6 +69,16 @@ func TestProcessNormalMsg(t *testing.T) {
 }
 
 func TestConfigUpdateMsg(t *testing.T) {
+	t.Run("BadUpdate", func(t *testing.T) {
+		ms := &mockSystemChannelFilterSupport{
+			ProposeConfigUpdateVal: &cb.ConfigEnvelope{},
+			ProposeConfigUpdateErr: fmt.Errorf("An error"),
+		}
+		config, cs, err := NewStandardChannel(ms, NewRuleSet(nil)).ProcessConfigUpdateMsg(&cb.Envelope{})
+		assert.Nil(t, config)
+		assert.Equal(t, uint64(0), cs)
+		assert.EqualError(t, err, "error applying config update to existing channel 'foo': An error")
+	})
 	t.Run("BadMsg", func(t *testing.T) {
 		ms := &mockSystemChannelFilterSupport{
 			ProposeConfigUpdateVal: &cb.ConfigEnvelope{},

orderer/common/msgprocessor/systemchannel.go

@@ -16,6 +16,8 @@ import (
 	"github.com/hyperledger/fabric/common/policies"
 	cb "github.com/hyperledger/fabric/protos/common"
 	"github.com/hyperledger/fabric/protos/utils"
+
+	"github.com/pkg/errors"
 )
 
 // ChannelConfigTemplator can be used to generate config templates.
@@ -101,7 +103,7 @@ func (s *SystemChannel) ProcessConfigUpdateMsg(envConfigUpdate *cb.Envelope) (co
 
 	newChannelConfigEnv, err := bundle.ConfigtxValidator().ProposeConfigUpdate(envConfigUpdate)
 	if err != nil {
-		return nil, 0, err
+		return nil, 0, errors.WithMessage(err, fmt.Sprintf("error validating channel creation transaction for new channel '%s', could not succesfully apply update to template configuration", channelID))
 	}
 
 	newChannelEnvConfig, err := utils.CreateSignedEnvelope(cb.HeaderType_CONFIG, channelID, s.support.Signer(), newChannelConfigEnv, msgVersion, epoch)

orderer/common/msgprocessor/systemchannel_test.go

@@ -140,7 +140,7 @@ func TestSystemChannelConfigUpdateMsg(t *testing.T) {
 				},
 			}),
 		})
-		assert.Equal(t, mscs.NewChannelConfigVal.ProposeConfigUpdateError, err)
+		assert.EqualError(t, err, "error validating channel creation transaction for new channel 'foodifferent', could not succesfully apply update to template configuration: An error")
 	})
 	t.Run("BadSignEnvelope", func(t *testing.T) {
 		mscs := &mockSystemChannelSupport{