今天我们来学下fabric-sdk-go的编写
区块链是未来互联网的发展趋势，区块链是一个信息技术领域的术语。从本质上讲，它是一个共享数据库，存储于其中的数据或信息，具有“不可伪造”“全程留痕”“可以追溯”“公开透明”“集体维护”等特征。基于这些特征，区块链技术奠定了坚实的“信任”基础，创造了可靠的“合作”机制，具有广阔的运用前景。
所以学习区块链也能够为自己多一份保障。
- 首先，在区块链网络搭建完成以及链码编写完成并已经上链后，我们便可编写区块链应用层得编写了，编写应用层需要先编写sdk（请确保自己gopath里面有github.com/hyperledger/fabric-sdk-go包)依赖包我已经上传了 Golang依赖包 可以自行下载。那么我们首先编写应用层的sdk。在编写sdk前需要完成sdk的配置文件，尤其是要进行通信的Fabric组件的地址。我们将所有内容放入一个新的配置文件，Fabric SDK Go配置和我们的自定义参数中。
使用如下命令创建config.yaml
cd $GOPATH/src/github.com/chainHero/heroes-service && \
vi config.yaml
以下是config.yaml的完整内容。
name: "heroes-service-network"
#
# Schema version of the content. Used by the SDK to apply the corresponding parsing rules.
#
version: 1.0.0
#
# The client section used by GO SDK.
#
client:
# Which organization does this application instance belong to? The value must be the name of an org
# defined under "organizations"
organization: org1
logging:
level: info
# Global configuration for peer, event service and orderer timeouts
# if this this section is omitted, then default values will be used (same values as below)
# peer:
# timeout:
# connection: 10s
# response: 180s
# discovery:
# # Expiry period for discovery service greylist filter
# # The channel client will greylist peers that are found to be offline
# # to prevent re-selecting them in subsequent retries.
# # This interval will define how long a peer is greylisted
# greylistExpiry: 10s
# eventService:
# # Event service type (optional). If not specified then the type is automatically
# # determined from channel capabilities.
# type: (deliver|eventhub)
# the below timeouts are commented out to use the default values that are found in
# "pkg/fab/endpointconfig.go"
# the client is free to override the default values by uncommenting and resetting
# the values as they see fit in their config file
# timeout:
# connection: 15s
# registrationResponse: 15s
# orderer:
# timeout:
# connection: 15s
# response: 15s
# global:
# timeout:
# query: 180s
# execute: 180s
# resmgmt: 180s
# cache:
# connectionIdle: 30s
# eventServiceIdle: 2m
# channelConfig: 30m
# channelMembership: 30s
# discovery: 10s
# selection: 10m
# Root of the MSP directories with keys and certs.
cryptoconfig:
path: ${GOPATH}/src/github.com/chainHero/heroes-service/fixtures/crypto-config
# Some SDKs support pluggable KV stores, the properties under "credentialStore"
# are implementation specific
credentialStore:
path: /tmp/heroes-service-store
# [Optional]. Specific to the CryptoSuite implementation used by GO SDK. Software-based implementations
# requiring a key store. PKCS#11 based implementations does not.
cryptoStore:
path: /tmp/heroes-service-msp
# BCCSP config for the client. Used by GO SDK.
BCCSP:
security:
enabled: true
default:
provider: "SW"
hashAlgorithm: "SHA2"
softVerify: true
level: 256
tlsCerts:
# [Optional]. Use system certificate pool when connecting to peers, orderers (for negotiating TLS) Default: false
systemCertPool: false
# [Optional]. Client key and cert for TLS handshake with peers and orderers
client:
keyfile:
certfile:
#
# [Optional]. But most apps would have this section so that channel objects can be constructed
# based on the content below. If an app is creating channels, then it likely will not need this
# section.
#
channels:
# name of the channel
chainhero:
# Required. list of orderers designated by the application to use for transactions on this
# channel. This list can be a result of access control ("org1" can only access "ordererA"), or
# operational decisions to share loads from applications among the orderers. The values must
# be "names" of orgs defined under "organizations/peers"
# deprecated: not recommended, to override any orderer configuration items, entity matchers should be used.
# orderers:
# - orderer.example.com
# Required. list of peers from participating orgs
peers:
peer0.org1.hf.chainhero.io:
# [Optional]. will this peer be sent transaction proposals for endorsement? The peer must
# have the chaincode installed. The app can also use this property to decide which peers
# to send the chaincode install request. Default: true
endorsingPeer: true
# [Optional]. will this peer be sent query proposals? The peer must have the chaincode
# installed. The app can also use this property to decide which peers to send the
# chaincode install request. Default: true
chaincodeQuery: true
# [Optional]. will this peer be sent query proposals that do not require chaincodes, like
# queryBlock(), queryTransaction(), etc. Default: true
ledgerQuery: true
# [Optional]. will this peer be the target of the SDK's listener registration? All peers can
# produce events but the app typically only needs to connect to one to listen to events.
# Default: true
eventSource: true
peer1.org1.hf.chainhero.io:
policies:
#[Optional] options for retrieving channel configuration blocks
queryChannelConfig:
#[Optional] min number of success responses (from targets/peers)
minResponses: 1
#[Optional] channel config will be retrieved for these number of random targets
maxTargets: 1
#[Optional] retry options for query config block
retryOpts:
#[Optional] number of retry attempts
attempts: 5
#[Optional] the back off interval for the first retry attempt
initialBackoff: 500ms
#[Optional] the maximum back off interval for any retry attempt
maxBackoff: 5s
#[Optional] he factor by which the initial back off period is exponentially incremented
backoffFactor: 2.0
#
# list of participating organizations in this network
#
organizations:
org1:
mspid: org1.hf.chainhero.io
cryptoPath: peerOrganizations/org1.hf.chainhero.io/users/{userName}@org1.hf.chainhero.io/msp
peers:
- peer0.org1.hf.chainhero.io
- peer1.org1.hf.chainhero.io
# [Optional]. Certificate Authorities issue certificates for identification purposes in a Fabric based
# network. Typically certificates provisioning is done in a separate process outside of the
# runtime network. Fabric-CA is a special certificate authority that provides a REST APIs for
# dynamic certificate management (enroll, revoke, re-enroll). The following section is only for
# Fabric-CA servers.
certificateAuthorities:
- ca.org1.hf.chainhero.io
#
# List of orderers to send transaction and channel create/update requests to. For the time
# being only one orderer is needed. If more than one is defined, which one get used by the
# SDK is implementation specific. Consult each SDK's documentation for its handling of orderers.
#
orderers:
orderer.hf.chainhero.io:
url: localhost:7050
# these are standard properties defined by the gRPC library
# they will be passed in as-is to gRPC client constructor
grpcOptions:
ssl-target-name-override: orderer.hf.chainhero.io
# These parameters should be set in coordination with the keepalive policy on the server,
# as incompatible settings can result in closing of connection.
# When duration of the 'keep-alive-time' is set to 0 or less the keep alive client parameters are disabled
keep-alive-time: 0s
keep-alive-timeout: 20s
keep-alive-permit: false
fail-fast: false
# allow-insecure will be taken into consideration if address has no protocol defined, if true then grpc or else grpcs
allow-insecure: false
tlsCACerts:
# Certificate location absolute path
path: ${GOPATH}/src/github.com/chainHero/heroes-service/fixtures/crypto-config/ordererOrganizations/hf.chainhero.io/tlsca/tlsca.hf.chainhero.io-cert.pem
#
# List of peers to send various requests to, including endorsement, query
# and event listener registration.
#
peers:
peer0.org1.hf.chainhero.io:
# this URL is used to send endorsement and query requests
url: localhost:7051
# eventUrl is only needed when using eventhub (default is delivery service)
eventUrl: localhost:7053
grpcOptions:
ssl-target-name-override: peer0.org1.hf.chainhero.io
# These parameters should be set in coordination with the keepalive policy on the server,
# as incompatible settings can result in closing of connection.
# When duration of the 'keep-alive-time' is set to 0 or less the keep alive client parameters are disabled
keep-alive-time: 0s
keep-alive-timeout: 20s
keep-alive-permit: false
fail-fast: false
# allow-insecure will be taken into consideration if address has no protocol defined, if true then grpc or else grpcs
allow-insecure: false
tlsCACerts:
# Certificate location absolute path
path: ${GOPATH}/src/github.com/chainHero/heroes-service/fixtures/crypto-config/peerOrganizations/org1.hf.chainhero.io/tlsca/tlsca.org1.hf.chainhero.io-cert.pem
peer1.org1.hf.chainhero.io:
# this URL is used to send endorsement and query requests
url: localhost:8051
# eventUrl is only needed when using eventhub (default is delivery service)
eventUrl: localhost:8053
grpcOptions:
ssl-target-name-override: peer1.org1.hf.chainhero.io
# These parameters should be set in coordination with the keepalive policy on the server,
# as incompatible settings can result in closing of connection.
# When duration of the 'keep-alive-time' is set to 0 or less the keep alive client parameters are disabled
keep-alive-time: 0s
keep-alive-timeout: 20s
keep-alive-permit: false
fail-fast: false
# allow-insecure will be taken into consideration if address has no protocol defined, if true then grpc or else grpcs
allow-insecure: false
tlsCACerts:
# Certificate location absolute path
path: ${GOPATH}/src/github.com/chainHero/heroes-service/fixtures/crypto-config/peerOrganizations/org1.hf.chainhero.io/tlsca/tlsca.org1.hf.chainhero.io-cert.pem
#
# Fabric-CA is a special kind of Certificate Authority provided by Hyperledger Fabric which allows
# certificate management to be done via REST APIs. Application may choose to use a standard
# Certificate Authority instead of Fabric-CA, in which case this section would not be specified.
#
certificateAuthorities:
ca.org1.hf.chainhero.io:
url: http://localhost:7054
# Fabric-CA supports dynamic user enrollment via REST APIs. A "root" user, a.k.a registrar, is
# needed to enroll and invoke new users.
httpOptions:
verify: false
registrar:
enrollId: admin
enrollSecret: adminpw
# [Optional] The optional name of the CA.
caName: ca.org1.hf.chainhero.io
tlsCACerts:
# Certificate location absolute path
path: ${GOPATH}/src/github.com/chainHero/heroes-service/fixtures/crypto-config/peerOrganizations/org1.hf.chainhero.io/ca/ca.org1.hf.chainhero.io-cert.pem
entityMatchers:
peer:
- pattern: (\w*)peer0.org1.hf.chainhero.io(\w*)
urlSubstitutionExp: localhost:7051
eventUrlSubstitutionExp: localhost:7053
sslTargetOverrideUrlSubstitutionExp: peer0.org1.hf.chainhero.io
mappedHost: peer0.org1.hf.chainhero.io
- pattern: (\w*)peer1.org1.hf.chainhero.io(\w*)
urlSubstitutionExp: localhost:8051
eventUrlSubstitutionExp: localhost:8053
sslTargetOverrideUrlSubstitutionExp: peer1.org1.hf.chainhero.io
mappedHost: peer1.org1.hf.chainhero.io
orderer:
- pattern: (\w*)orderer.hf.chainhero.io(\w*)
urlSubstitutionExp: localhost:7050
sslTargetOverrideUrlSubstitutionExp: orderer.hf.chainhero.io
mappedHost: orderer.hf.chainhero.io
certificateAuthorities:
- pattern: (\w*)ca.org1.hf.chainhero.io(\w*)
urlSubstitutionExp: http://localhost:7054
mappedHost: ca.org1.hf.chainhero.io
接下来我们需要创建一个文件夹
mkdir $GOPATH/src/github.com/chainHero/heroes-service/blockchain
创建一个文件为sdk.go
vi $GOPATH/src/github.com/chainHero/heroes-service/blockchain/sdk.go
便可以编写SDK了，代码如下。
package blockchain
import (
"github.com/hyperledger/fabric-sdk-go/pkg/client/channel"
"github.com/hyperledger/fabric-sdk-go/pkg/core/config"
"github.com/hyperledger/fabric-sdk-go/pkg/fabsdk"
)
var (
SDK *fabsdk.FabricSDK//定义一个指向fabsdk.go里面的FabricSDK的结构体
ChannelName = "mychannel"//当前将要访问的智能合约所属通道名称
ChaincodeName = "mycc"//网络编写时的链码名称
Org = "org1"
User = "Admin"
ConfigPath = "/home/work/go/src/trace-back/application/config.yaml"//configPath配置路径
TargetEndPoint1 = "node2.organization1.gdzce.cn"//指定背书节点
TargetEndPoint2 = "node2.organization2.gdzce.cn"//指定背书节点
TargetEndPoint3 = "node2.organization3.gdzce.cn"//指定背书节点
)
// 初始化
func Init() {
var err error
SDK, err = fabsdk.New(config.FromFile(ConfigPath))
if err != nil {
panic(err)
}
}
// 交互
func ChannelExecute(fcn string, args [][]byte) (channel.Response, error) {
// 创建客户端
ctx := SDK.ChannelContext(ChannelName, fabsdk.WithOrg(Org), fabsdk.WithUser(User))
cli, err := channel.New(ctx)
if err != nil {
return channel.Response{}, err
}
resp, err := cli.Execute(channel.Request{
ChaincodeID: ChaincodeName,
Fcn: fcn,
Args: args,
}, channel.WithTargetEndpoints(TargetEndPoint1, TargetEndPoint2, TargetEndPoint3))
if err != nil {
return channel.Response{}, err
}
return resp, nil
}
// 查询
func ChannelQuery(fcn string, args [][]byte) (channel.Response, error) {
// 创建客户端
ctx := SDK.ChannelContext(ChannelName, fabsdk.WithOrg(Org), fabsdk.WithUser(User))
cli, err := channel.New(ctx)
if err != nil {
return channel.Response{}, err
}
return cli.Query(channel.Request{
ChaincodeID: ChaincodeName,
Fcn: fcn,
Args: args,
}, channel.WithTargetEndpoints(TargetEndPoint1, TargetEndPoint2, TargetEndPoint3))
}
这便完成了sdk的编写了，其它的后面再说。