[FAB-8211] Expose ledger from channel svc

This patch exposes the ledger interface from
a client's channel service. The integration tests
related to ledger queries are adjusted to use this
interface.

Change-Id: I6ccf8455583f5f62e8fdb1982482853aab315efd
Signed-off-by: Troy Ronda <troy@troyronda.com>

Author: troyronda

README.md

@@ -23,6 +23,7 @@ You're good to go, happy coding! Check out the examples for usage demonstrations
 ### Examples
 
 - [E2E Test](test/integration/e2e/end_to_end.go): Basic example that uses SDK to query and execute transaction
+- [Ledger Query Test](test/integration/fab/channel_ledger_test.go): Basic example that uses SDK to query a channel's underlying ledger
 - [Multi Org Test](test/integration/orgs/multiple_orgs_test.go): An example that has multiple organisations involved in transaction
 - [Dynamic Endorser Selection](test/integration/sdk/sdk_provider_test.go): An example that uses dynamic endorser selection (based on chaincode policy) 
 - [E2E PKCS11 Test](test/integration/pkcs11/e2e_test.go): E2E Test using a PKCS11 crypto suite and configuration

api/apifabclient/channel.go

@@ -61,11 +61,11 @@ type Channel interface {
 
 // ChannelLedger provides access to the underlying ledger for a channel.
 type ChannelLedger interface {
-	QueryInfo(targets []ProposalProcessor) (*common.BlockchainInfo, error)
-	QueryBlock(blockNumber int, targets []ProposalProcessor) (*common.Block, error)
-	QueryBlockByHash(blockHash []byte, targets []ProposalProcessor) (*common.Block, error)
-	QueryTransaction(transactionID string, targets []ProposalProcessor) (*pb.ProcessedTransaction, error)
-	QueryInstantiatedChaincodes(targets []ProposalProcessor) (*pb.ChaincodeQueryResponse, error)
+	QueryInfo(targets []ProposalProcessor) ([]*common.BlockchainInfo, error)
+	QueryBlock(blockNumber int, targets []ProposalProcessor) ([]*common.Block, error)
+	QueryBlockByHash(blockHash []byte, targets []ProposalProcessor) ([]*common.Block, error)
+	QueryTransaction(transactionID string, targets []ProposalProcessor) ([]*pb.ProcessedTransaction, error)
+	QueryInstantiatedChaincodes(targets []ProposalProcessor) ([]*pb.ChaincodeQueryResponse, error)
 }
 
 // OrgAnchorPeer contains information about an anchor peer on this channel

api/apifabclient/context.go

@@ -32,6 +32,7 @@ type ChannelProvider interface {
 // ChannelService supplies services related to a channel.
 type ChannelService interface {
 	ChannelConfig() (ChannelConfig, error)
+	Ledger() (ChannelLedger, error)
 	Channel() (Channel, error)
 	EventHub() (EventHub, error) // TODO support new event delivery
 }

api/apifabclient/resource.go

@@ -15,8 +15,8 @@ import (
 type Resource interface {
 	CreateChannel(request CreateChannelRequest) (TransactionID, error)
 	InstallChaincode(request InstallChaincodeRequest) ([]*TransactionProposalResponse, string, error)
-	QueryInstalledChaincodes(peer Peer) (*pb.ChaincodeQueryResponse, error)
-	QueryChannels(peer Peer) (*pb.ChannelQueryResponse, error)
+	QueryInstalledChaincodes(peer ProposalProcessor) (*pb.ChaincodeQueryResponse, error)
+	QueryChannels(peer ProposalProcessor) (*pb.ChannelQueryResponse, error)
 
 	GenesisBlockFromOrderer(channelName string, orderer Orderer) (*common.Block, error)
 	JoinChannel(request JoinChannelRequest) error

pkg/fabric-client/channel/channel.go

@@ -331,7 +331,11 @@ func resolveOrdererURL(ordererURL string) string {
 // (height, known peers).
 // This query will be made to the primary peer.
 func (c *Channel) QueryInfo() (*common.BlockchainInfo, error) {
-	l := NewLedger(c.clientContext, c.name)
+	l, err := NewLedger(c.clientContext, c.name)
+	if err != nil {
+		return nil, errors.WithMessage(err, "ledger client creation failed")
+	}
+
 	resps, err := l.QueryInfo([]fab.ProposalProcessor{c.PrimaryPeer()})
 	if err != nil {
 		return nil, err
@@ -343,7 +347,11 @@ func (c *Channel) QueryInfo() (*common.BlockchainInfo, error) {
 // This query will be made to the primary peer.
 // Returns the block.
 func (c *Channel) QueryBlockByHash(blockHash []byte) (*common.Block, error) {
-	l := NewLedger(c.clientContext, c.name)
+	l, err := NewLedger(c.clientContext, c.name)
+	if err != nil {
+		return nil, errors.WithMessage(err, "ledger client creation failed")
+	}
+
 	resps, err := l.QueryBlockByHash(blockHash, []fab.ProposalProcessor{c.PrimaryPeer()})
 	if err != nil {
 		return nil, err
@@ -356,7 +364,11 @@ func (c *Channel) QueryBlockByHash(blockHash []byte) (*common.Block, error) {
 // blockNumber: The number which is the ID of the Block.
 // It returns the block.
 func (c *Channel) QueryBlock(blockNumber int) (*common.Block, error) {
-	l := NewLedger(c.clientContext, c.name)
+	l, err := NewLedger(c.clientContext, c.name)
+	if err != nil {
+		return nil, errors.WithMessage(err, "ledger client creation failed")
+	}
+
 	resps, err := l.QueryBlock(blockNumber, []fab.ProposalProcessor{c.PrimaryPeer()})
 	if err != nil {
 		return nil, err
@@ -369,7 +381,11 @@ func (c *Channel) QueryBlock(blockNumber int) (*common.Block, error) {
 // Returns the ProcessedTransaction information containing the transaction.
 // TODO: add optional target
 func (c *Channel) QueryTransaction(transactionID string) (*pb.ProcessedTransaction, error) {
-	l := NewLedger(c.clientContext, c.name)
+	l, err := NewLedger(c.clientContext, c.name)
+	if err != nil {
+		return nil, errors.WithMessage(err, "ledger client creation failed")
+	}
+
 	resps, err := l.QueryTransaction(transactionID, []fab.ProposalProcessor{c.PrimaryPeer()})
 	if err != nil {
 		return nil, err
@@ -380,7 +396,11 @@ func (c *Channel) QueryTransaction(transactionID string) (*pb.ProcessedTransacti
 // QueryInstantiatedChaincodes queries the instantiated chaincodes on this channel.
 // This query will be made to the primary peer.
 func (c *Channel) QueryInstantiatedChaincodes() (*pb.ChaincodeQueryResponse, error) {
-	l := NewLedger(c.clientContext, c.name)
+	l, err := NewLedger(c.clientContext, c.name)
+	if err != nil {
+		return nil, errors.WithMessage(err, "ledger client creation failed")
+	}
+
 	resps, err := l.QueryInstantiatedChaincodes([]fab.ProposalProcessor{c.PrimaryPeer()})
 	if err != nil {
 		return nil, err
@@ -392,7 +412,11 @@ func (c *Channel) QueryInstantiatedChaincodes() (*pb.ChaincodeQueryResponse, err
 // QueryConfigBlock returns the current configuration block for the specified channel. If the
 // peer doesn't belong to the channel, return error
 func (c *Channel) QueryConfigBlock(peers []fab.Peer, minResponses int) (*common.ConfigEnvelope, error) {
-	l := NewLedger(c.clientContext, c.name)
+	l, err := NewLedger(c.clientContext, c.name)
+	if err != nil {
+		return nil, errors.WithMessage(err, "ledger client creation failed")
+	}
+
 	return l.QueryConfigBlock(peers, minResponses)
 }
 

pkg/fabric-client/channel/ledger.go

@@ -32,12 +32,12 @@ type Ledger struct {
 }
 
 // NewLedger constructs a Ledger client for the current context and named channel.
-func NewLedger(ctx fab.Context, chName string) *Ledger {
+func NewLedger(ctx fab.Context, chName string) (*Ledger, error) {
 	l := Ledger{
 		ctx:    ctx,
 		chName: chName,
 	}
-	return &l
+	return &l, nil
 }
 
 // QueryInfo queries for various useful information on the state of the channel

pkg/fabric-client/channel/ledger_test.go

@@ -181,5 +181,5 @@ func setupTestLedger() (*Ledger, error) {
 func setupLedger(channelID string) (*Ledger, error) {
 	user := mocks.NewMockUser("test")
 	ctx := mocks.NewMockContext(user)
-	return NewLedger(ctx, channelID), nil
+	return NewLedger(ctx, channelID)
 }

pkg/fabric-client/mocks/mockchprovider.go

@@ -68,3 +68,8 @@ func (cs *MockChannelService) Channel() (fab.Channel, error) {
 func (cs *MockChannelService) ChannelConfig() (fab.ChannelConfig, error) {
 	return nil, nil
 }
+
+// Ledger ...
+func (cs *MockChannelService) Ledger() (fab.ChannelLedger, error) {
+	return nil, nil
+}

pkg/fabric-client/mocks/mockresource.go

@@ -58,7 +58,7 @@ func (c *MockResource) CreateChannel(request fab.CreateChannelRequest) (fab.Tran
 }
 
 //QueryChannels ...
-func (c *MockResource) QueryChannels(peer fab.Peer) (*pb.ChannelQueryResponse, error) {
+func (c *MockResource) QueryChannels(peer fab.ProposalProcessor) (*pb.ChannelQueryResponse, error) {
 	return nil, errors.New("Not implemented yet")
 }
 
@@ -77,7 +77,7 @@ func (c *MockResource) JoinChannel(request fab.JoinChannelRequest) error {
 }
 
 //QueryInstalledChaincodes mocks query installed chaincodes
-func (c *MockResource) QueryInstalledChaincodes(peer fab.Peer) (*pb.ChaincodeQueryResponse, error) {
+func (c *MockResource) QueryInstalledChaincodes(peer fab.ProposalProcessor) (*pb.ChaincodeQueryResponse, error) {
 	if peer == nil {
 		return nil, errors.New("Generate Error")
 	}

pkg/fabric-client/resource/resource.go

@@ -321,7 +321,7 @@ func (c *Resource) createOrUpdateChannel(request fab.CreateChannelRequest, haveE
 }
 
 // QueryChannels queries the names of all the channels that a peer has joined.
-func (c *Resource) QueryChannels(peer fab.Peer) (*pb.ChannelQueryResponse, error) {
+func (c *Resource) QueryChannels(peer fab.ProposalProcessor) (*pb.ChannelQueryResponse, error) {
 
 	if peer == nil {
 		return nil, errors.New("peer required")
@@ -346,7 +346,7 @@ func (c *Resource) QueryChannels(peer fab.Peer) (*pb.ChannelQueryResponse, error
 
 // QueryInstalledChaincodes queries the installed chaincodes on a peer.
 // Returns the details of all chaincodes installed on a peer.
-func (c *Resource) QueryInstalledChaincodes(peer fab.Peer) (*pb.ChaincodeQueryResponse, error) {
+func (c *Resource) QueryInstalledChaincodes(peer fab.ProposalProcessor) (*pb.ChaincodeQueryResponse, error) {
 
 	if peer == nil {
 		return nil, errors.New("peer required")