区块链怎么搭建 – dpfak福利网站

区块链怎么搭建 – dpfak福利网站
随着数字经济的发展，区块链技术越来越受到人们的重视。区块链技术的核心在于分布式账本，它可以保证数据的完整性和不可篡改性，在很多领域有着广泛的应用。本文将介绍如何搭建一条简单的区块链，并将其应用于dpfak福利网站。
1. 准备环境
搭建区块链需要一些基础的软件和工具，包括：Golang、git、Docker、Docker Compose等。在开始搭建之前，需要确保这些软件和工具已经正确安装并配置好了。
2. 编写智能合约
智能合约是区块链的核心，它定义了区块链的运行逻辑和规则。在这里，我们为dpfak福利网站编写一个简单的智能合约，它记录了用户的账户余额和交易记录。
“`
package main
import (
\”fmt\”
\”github.com/hyperledger/fabric-contract-api-go/contractapi\”
)
type WlContract struct {
contractapi.Contract
}
type Account struct {
User string `json:\”user\”`
Balance int `json:\”balance\”`
Transactions []string `json:\”transactions\”`
}
func (c *WlContract) GetBalance(ctx contractapi.TransactionContextInterface, user string) (int, error) {
accountJSON, err := ctx.GetStub().GetState(user)
if err != nil {
return 0, err
}
if accountJSON == nil {
return 0, fmt.Errorf(\”the account %s does not exist\”, user)
}
var account Account
err = json.Unmarshal(account, &Account)
if err != nil {
return 0, err
}
return account.Balance, nil
}
func (c *WlContract) Transfer(ctx contractapi.TransactionContextInterface, from string, to string, amount int) error {
fromAccount, err := ctx.GetStub().GetState(from)
if err != nil {
return err
}
if fromAccount == nil {
return fmt.Errorf(\”the account %s does not exist\”, from)
}
var fromAccount Account
err = json.Unmarshal(fromAccount, &fromAccount)
if err != nil {
return err
}
if fromAccount.Balance < amount { return fmt.Errorf(\"the account %s does not have enough balance\", from) } toAccount, err := ctx.GetStub().GetState(to) if err != nil { return err } if toAccount == nil { toAccount = &Account{User: to, Balance: 0, Transactions: make([]string, 0)} } var toAccount Account err = json.Unmarshal(toAccount, &toAccount) if err != nil { return err } fromAccount.Balance -= amount toAccount.Balance += amount fromAccount.Transactions = append(fromAccount.Transactions, fmt.Sprintf(\"Transfer to %s, amount=%d\", to, amount)) toAccount.Transactions = append(toAccount.Transactions, fmt.Sprintf(\"Transfer from %s, amount=%d\", from, amount)) fromAccountJSON, err := json.Marshal(fromAccount) if err != nil { return err } err = ctx.GetStub().PutState(from, fromAccountJSON) if err != nil { return err } toAccountJSON, err := json.Marshal(toAccount) if err != nil { return err } err = ctx.GetStub().PutState(to, toAccountJSON) if err != nil { return err } return nil } ``` 3. 部署智能合约 在部署智能合约之前，我们需要使用Golang编译它，并把编译后的二进制文件打包成Docker镜像。 ``` $ go build -o wl ./... $ docker build -t wl:latest . ``` 然后，我们可以使用Docker Compose来启动一个Fabric网络和部署链代码，包括我们的智能合约。 ``` version: '2' networks: blockchain: services: orderer.example.com: container_name: orderer.example.com image: hyperledger/fabric-orderer environment: - ORDERER_GENERAL_LOGLEVEL=debug - ORDERER_GENERAL_LISTENADDRESS=0.0.0.0 - ORDERER_GENERAL_GENESISMETHOD=file - ORDERER_GENERAL_GENESISFILE=/var/hyperledger/orderer/genesis.block - ORDERER_GENERAL_LOCALMSPID=OrdererMSP volumes: - ./ledger/orderer:/var/hyperledger/production/orderer - ./config/orderer/genesis.block:/var/hyperledger/orderer/genesis.block - ./config/orderer/tls:/var/hyperledger/orderer/tls networks: - blockchain peer0.org1.example.com: container_name: peer0.org1.example.com image: hyperledger/fabric-peer environment: - CORE_VM_ENDPOINT=unix:///var/run/docker.sock - CORE_VM_DOCKER_HOSTCONFIG_NETWORKMODE=${COMPOSE_PROJECT_NAME}_blockchain - CORE_PEER_ID=peer0.org1.example.com - CORE_PEER_ADDRESS=peer0.org1.example.com:7051 - CORE_PEER_LISTENADDRESS=0.0.0.0:7051 - CORE_PEER_CHAINCODEADDRESS=peer0.org1.example.com:7052 - CORE_PEER_CHAINCODELISTENADDRESS=0.0.0.0:7052 - CORE_PEER_GOSSIP_BOOTSTRAP=peer0.org1.example.com:7051 - CORE_PEER_GOSSIP_ENDPOINT=peer0.org1.example.com:7051 - CORE_PEER_GOSSIP_EXTERNALENDPOINT=peer0.org1.example.com:7051 - CORE_PEER_GOSSIP_USELEADERELECTION=true - CORE_PEER_LOCALMSPID=Org1MSP - CORE_PEER_MSPCONFIGPATH=/etc/hyperledger/msp/peer/ - CORE_PEER_TLS_ENABLED=true - CORE_PEER_TLS_ROOTCERT_FILE=/etc/hyperledger/tls/ca.crt volumes: - ./ledger/peer0.org1.example.com:/var/hyperledger/production - ./config/peer/tls:/etc/hyperledger/tls - ./config/peer/msp:/etc/hyperledger/msp/peer - ./config/peer/core.yaml:/etc/hyperledger/fabric/core.yaml - /var/run/docker.sock:/var/run/docker.sock depends_on: - orderer.example.com networks: - blockchain wl: container_name: wl image: wl:latest environment: - CORE_PEER_ADDRESS=peer0.org1.example.com:7052 - CORE_CHAINCODE_ID_NAME=mycc:1.0 - CORE_CHAINCODE_LOGGING_LEVEL=DEBUG volumes: - ./config/chaincode/:/opt/gopath/src/wl depends_on: - peer0.org1.example.com networks: - blockchain ``` 4. 集成dpfak福利网站 我们为dpfak福利网站提供一个简单的API，使其可以与我们的区块链进行交互。这个API包括两个端点，一个是获取账户余额，一个是转账。 ``` package main import ( \"net/http\" \"encoding/json\" \"github.com/gorilla/mux\" \"github.com/hyperledger/fabric-sdk-go/pkg/fab/ccpackager/gopackager\" \"github.com/hyperledger/fabric-sdk-go/pkg/gateway\" ) func main() { router := mux.NewRouter() router.HandleFunc(\"/balance/{user}\", GetBalance).Methods(\"GET\") router.HandleFunc(\"/transfer/{from}/{to}/{amount}\", Transfer).Methods(\"POST\") http.ListenAndServe(\":8080\", router) } func GetBalance(w http.ResponseWriter, r *http.Request) { user := mux.Vars(r)[\"user\"] contract := ConnectToChaincode(user) defer contract.Close() balance, err := contract.EvaluateTransaction(\"GetBalance\", user) if err != nil { http.Error(w, err.Error(), http.StatusInternalServerError) return } w.Header().Set(\"Content-Type\", \"application/json\") w.Write(balance) } func Transfer(w http.ResponseWriter, r *http.Request) { from := mux.Vars(r)[\"from\"] to := mux.Vars(r)[\"to\"] amount := mux.Vars(r)[\"amount\"] contract := ConnectToChaincode(from) defer contract.Close() err := contract.SubmitTransaction(\"Transfer\", from, to, amount) if err != nil { http.Error(w, err.Error(), http.StatusInternalServerError) return } w.WriteHeader(http.StatusOK) } func ConnectToChaincode(user string) *gateway.Contract { wallet := gateway.NewFileSystemWallet(\"/opt/wallet\") gatewayOpts := gateway.WithUserAndOrg(user, \"Org1\") gatewayInstance, err := gateway.Connect(gatewayOpts) if err != nil { log.Fatalf(\"failed to connect to Fabric gateway: %v\", err) } network, err := gatewayInstance.GetNetwork(\"mychannel\") if err != nil { log.Fatalf(\"failed to get network: %v\", err) } contract := network.GetContract(\"mycc\") return contract } ``` 以上就是搭建区块链并集成dpfak福利网站的完整过程。通过区块链技术，可以保证dpfak福利网站的用户账户余额和交易记录的安全性和不可篡改性。同时，区块链技术也为dpfak福利网站的数据管理和隐私保护提供了良好的支持。