基于tendermint开发区块链

• Tendermint介绍

Tendermint包括两大组件，tendermint core和ABCI两大组件，开发者只要实现ABCI的接口即可定制开发自己的区块链逻辑。

• 开发自己的代码

安装tendermint core

go get github.com/tendermint/tendermint/cmd/tendermint
go install ./cmd/...
go get github.com/Masterminds/glide
cd $GOPATH/src/github.com/tendermint/tendermint
glide install
go install ./cmd/...

编写ABCI代码

新增ezapp.go,实现CheckTx方法，对放入mempool的交易进行校验

package ezapp

import (
	"bytes"
	"encoding/binary"
	"github.com/tendermint/tendermint/abci/types"
)

var _ types.Application = (*Application)(nil)

type Application struct {
	types.BaseApplication
}

func NewApplication() *Application {
	return &Application{}
}
func (app *Application) CheckTx(req types.RequestCheckTx) types.ResponseCheckTx {
	bin_buf := bytes.NewBuffer(req.Tx)
	var x int32
	binary.Read(bin_buf, binary.BigEndian, &x)
	if  x < 0x04 {
		return types.ResponseCheckTx{}
	}
	return types.ResponseCheckTx{Code:1,Log:"bad tx rejected"}
}

修改abci-cli.go，见代码中注释ezapp处。

var RootCmd = &cobra.Command{
	Use:   "abci-cli",
	Short: "the ABCI CLI tool wraps an ABCI client",
	Long:  "the ABCI CLI tool wraps an ABCI client and is used for testing ABCI servers",
	PersistentPreRunE: func(cmd *cobra.Command, args []string) error {

		switch cmd.Use {
		//ezapp，增加一个ezapp，否则启动后一直会报错
		case "counter", "kvstore","ezapp": // for the examples apps, don't pre-run
			return nil
		case "version": // skip running for version command
			return nil
		}

		if logger == nil {
			allowLevel, err := log.AllowLevel(flagLogLevel)
			if err != nil {
				return err
			}
			logger = log.NewFilter(log.NewTMLogger(log.NewSyncWriter(os.Stdout)), allowLevel)
		}
		if client == nil {
			var err error
			client, err = abcicli.NewClient(flagAddress, flagAbci, false)
			if err != nil {
				return err
			}
			client.SetLogger(logger.With("module", "abci-client"))
			if err := client.Start(); err != nil {
				return err
			}
		}
		return nil
	},
}
//增加addezappFlags方法
func addezappFlags() {
	ezappCmd.PersistentFlags().StringVarP(&flagPersist, "persist", "", "", "directory to use for a database")
}
func addCommands() {
	RootCmd.AddCommand(batchCmd)
	RootCmd.AddCommand(consoleCmd)
	RootCmd.AddCommand(echoCmd)
	RootCmd.AddCommand(infoCmd)
	RootCmd.AddCommand(setOptionCmd)
	RootCmd.AddCommand(deliverTxCmd)
	RootCmd.AddCommand(checkTxCmd)
	RootCmd.AddCommand(commitCmd)
	RootCmd.AddCommand(versionCmd)
	RootCmd.AddCommand(testCmd)
	addQueryFlags()
	RootCmd.AddCommand(queryCmd)
	// examples
	addCounterFlags()
	RootCmd.AddCommand(counterCmd)
	addKVStoreFlags()
	RootCmd.AddCommand(kvstoreCmd)

	//ezapp增加这两行代码
	addezappFlags()
	RootCmd.AddCommand(ezappCmd)
}

//ezapp，新增ezappCmd
var ezappCmd = &cobra.Command{
	Use:   "ezapp",
	Short: "ezapp demo example",
	Long:  "ezapp demo example",
	Args:  cobra.ExactArgs(0),
	RunE:  cmdEzapp,
}
func cmdEzapp(cmd *cobra.Command, args []string) error {
	var app types.Application
	app = ezapp.NewApplication()
	logger := log.NewTMLogger(log.NewSyncWriter(os.Stdout))

	// Start the listener
	srv, err := server.NewServer(flagAddress, flagAbci, app)
	if err != nil {
		return err
	}
	srv.SetLogger(logger.With("module", "abci-server"))
	if err := srv.Start(); err != nil {
		return err
	}
	// Stop upon receiving SIGTERM or CTRL-C.
	tmos.TrapSignal(logger, func() {
		// Cleanup
		srv.Stop()
	})
	// Run forever.
	select {}
}

编译运行abci-cli

cd %GOPATH/src/github.com/tendermint/abci/cmd/abci-cli
go build
abci-cli ezapp

启动tendermint core

tendermint init
tendermint node

• 调试区块链接口

curl -l http://localhost:26657/broadcast_tx_commit?tx=2

{
  "jsonrpc": "2.0",
  "id": -1,
  "result": {
    "check_tx": {
      "code": 0,
      "data": null,
      "log": "",
      "info": "",
      "gasWanted": "0",
      "gasUsed": "0",
      "events": [],
      "codespace": ""
    },
    "deliver_tx": {
      "code": 0,
      "data": null,
      "log": "",
      "info": "",
      "gasWanted": "0",
      "gasUsed": "0",
      "events": [],
      "codespace": ""
    },
    "hash": "D4735E3A265E16EEE03F59718B9B5D03019C07D8B6C51F90DA3A666EEC13AB35",
    "height": "7"
  }
}