Fabric的第一个链码操作

1、链码的安装

切换到节点1上，如果不切换可不可以呢？链码是安装在节点上的？还是安装在通道上的？

CORE_PEER_LOCALMSPID="Org1MSP"
 CORE_PEER_TLS_ROOTCERT_FILE=/opt/gopath/src/github.com/hyperledger/fabric/peer/crypto/peerOrganizations/org1.example.com/peers/peer0.org1.example.com/tls/ca.crt 
CORE_PEER_MSPCONFIGPATH=/opt/gopath/src/github.com/hyperledger/fabric/peer/crypto/peerOrganizations/org1.example.com/users/Admin@org1.example.com/msp
CORE_PEER_ADDRESS=peer0.org1.example.com:7051

然后再进行链码的安装

peer chaincode install -n mycc -v 1.0 -p github.com/chaincode/chaincode_example02/test/

安装成功会出现以下截图 

 

2、链码的实例化

peer chaincode instantiate -o orderer.example.com:7050 --tls --cafile /opt/gopath/src/github.com/hyperledger/fabric/peer/crypto/ordererOrganizations/example.com/orderers/orderer.example.com/msp/tlscacerts/tlsca.example.com-cert.pem -C $CHANNEL_NAME -n mycc -v 1.0 -c '{"Args":["init","a", "100", "b","200"]}' -P "OR ('Org1MSP.peer','Org2MSP.peer')"

实例化成功之后会出现以下截图

 

3、链码的更新

一旦实例化成功之后，再更新链码，都是需要重新安装，然后再更新的（upgrade)，注意要更新版本号！

peer chaincode install -n mycc -v 12.0 -p github.com/chaincode/chaincode_example02/test/

 

更新链码 

peer chaincode upgrade -o orderer.example.com:7050 --tls --cafile /opt/gopath/src/github.com/hyperledger/fabric/peer/crypto/ordererOrganizations/example.com/orderers/orderer.example.com/msp/tlscacerts/tlsca.example.com-cert.pem -C $CHANNEL_NAME -n mycc -v 12.0 -c '{"Args":["init","a", "100", "b","200"]}' -P "OR ('Org1MSP.peer','Org2MSP.peer')"

如果实例化没成功的话，就是重新安装，然后再实例化，成功会产生如下截图

4、链码的调用

注意：在Fabric1.4中invoke是链码中其他函数的入口，也就是在这一层调用其他函数

实现数据存储上链：

 peer chaincode invoke -o orderer.example.com:7050  --tls --cafile /opt/gopath/src/github.com/hyperledger/fabric/peer/crypto/ordererOrganizations/example.com/orderers/orderer.example.com/msp/tlscacerts/tlsca.example.com-cert.pem  -C $CHANNEL_NAME -n mycc -c '{"Args":["save","a","b"]}'

实现数据查询： 

peer chaincode invoke -o orderer.example.com:7050  --tls --cafile /opt/gopath/src/github.com/hyperledger/fabric/peer/crypto/ordererOrganizations/example.com/orderers/orderer.example.com/msp/tlscacerts/tlsca.example.com-cert.pem  -C $CHANNEL_NAME -n mycc -c '{"Args":["query","a"]}'

查询结果截图 

 

5、我的第一个链码

/*
Copyright IBM Corp. 2016 All Rights Reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

		 http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package main

//WARNING - this chaincode's ID is hard-coded in chaincode_example04 to illustrate one way of
//calling chaincode from a chaincode. If this example is modified, chaincode_example04.go has
//to be modified as well with the new ID of chaincode_example02.
//chaincode_example05 show's how chaincode ID can be passed in as a parameter instead of
//hard-coding.

import (
	"fmt"
	"strconv"

	"github.com/hyperledger/fabric/core/chaincode/shim"
	pb "github.com/hyperledger/fabric/protos/peer"
)

// SimpleChaincode example simple Chaincode implementation
type SimpleChaincode struct {
}

func (t *SimpleChaincode) Init(stub shim.ChaincodeStubInterface) pb.Response {
	fmt.Println("ex02 Init")
	_, args := stub.GetFunctionAndParameters()
	var A, B string    // Entities
	var Aval, Bval int // Asset holdings
	var err error

	if len(args) != 4 {
		return shim.Error("Incorrect number of arguments. Expecting 4")
	}

	// Initialize the chaincode
	A = args[0]
	Aval, err = strconv.Atoi(args[1])
	if err != nil {
		return shim.Error("Expecting integer value for asset holding")
	}
	B = args[2]
	Bval, err = strconv.Atoi(args[3])
	if err != nil {
		return shim.Error("Expecting integer value for asset holding")
	}
	fmt.Printf("Aval = %d, Bval = %d\n", Aval, Bval)

	// Write the state to the ledger
	err = stub.PutState(A, []byte(strconv.Itoa(Aval)))
	if err != nil {
		return shim.Error(err.Error())
	}

	err = stub.PutState(B, []byte(strconv.Itoa(Bval)))
	if err != nil {
		return shim.Error(err.Error())
	}

	return shim.Success(nil)
}

func (t *SimpleChaincode) Invoke(stub shim.ChaincodeStubInterface) pb.Response {
	fmt.Println("ex02 Invoke")
	function, args := stub.GetFunctionAndParameters()
	if function == "invoke" {
		// Make payment of X units from A to B
		return t.invoke(stub, args)
	} else if function == "delete" {
		// Deletes an entity from its state
		return t.delete(stub, args)
	} else if function == "query" {
		// the old "Query" is now implemtned in invoke
		return t.query(stub, args)
	}else if function == "save"{
		return t.save(stub, args)
	}

	return shim.Error("Invalid invoke function name. Expecting \"invoke\" \"delete\" \"query\"")
}

func (t *SimpleChaincode) save(stub shim.ChaincodeStubInterface, args []string) pb.Response {
	fmt.Println("My first Chaincode")

	//_, args := stub.GetFunctionAndParameters()
	err := stub.PutState(args[0], []byte(args[1]))
	if err != nil {
		fmt.Printf("Error starting Simple chaincode: %s", err)
	}
	return shim.Success(nil)
}

// Transaction makes payment of X units from A to B
func (t *SimpleChaincode) invoke(stub shim.ChaincodeStubInterface, args []string) pb.Response {
	var A, B string    // Entities
	var Aval, Bval int // Asset holdings
	var X int          // Transaction value
	var err error

	if len(args) != 3 {
		return shim.Error("Incorrect number of arguments. Expecting 3")
	}

	A = args[0]
	B = args[1]

	// Get the state from the ledger
	// TODO: will be nice to have a GetAllState call to ledger
	Avalbytes, err := stub.GetState(A)
	if err != nil {
		return shim.Error("Failed to get state")
	}
	if Avalbytes == nil {
		return shim.Error("Entity not found")
	}
	Aval, _ = strconv.Atoi(string(Avalbytes))

	Bvalbytes, err := stub.GetState(B)
	if err != nil {
		return shim.Error("Failed to get state")
	}
	if Bvalbytes == nil {
		return shim.Error("Entity not found")
	}
	Bval, _ = strconv.Atoi(string(Bvalbytes))

	// Perform the execution
	X, err = strconv.Atoi(args[2])
	if err != nil {
		return shim.Error("Invalid transaction amount, expecting a integer value")
	}
	Aval = Aval - X
	Bval = Bval + X
	fmt.Printf("Aval = %d, Bval = %d\n", Aval, Bval)

	// Write the state back to the ledger
	err = stub.PutState(A, []byte(strconv.Itoa(Aval)))
	if err != nil {
		return shim.Error(err.Error())
	}

	err = stub.PutState(B, []byte(strconv.Itoa(Bval)))
	if err != nil {
		return shim.Error(err.Error())
	}

	return shim.Success(nil)
}

// Deletes an entity from state
func (t *SimpleChaincode) delete(stub shim.ChaincodeStubInterface, args []string) pb.Response {
	if len(args) != 1 {
		return shim.Error("Incorrect number of arguments. Expecting 1")
	}

	A := args[0]

	// Delete the key from the state in ledger
	err := stub.DelState(A)
	if err != nil {
		return shim.Error("Failed to delete state")
	}

	return shim.Success(nil)
}

// query callback representing the query of a chaincode
func (t *SimpleChaincode) query(stub shim.ChaincodeStubInterface, args []string) pb.Response {
	var A string // Entities
	var err error

	A = args[0]

	// Get the state from the ledger
	Avalbytes, err := stub.GetState(A)
	if err != nil {
		jsonResp := "{\"Error\":\"Failed to get state for " + A + "\"}"
		return shim.Error(jsonResp)
	}

	if Avalbytes == nil {
		jsonResp := "{\"Error\":\"Nil amount for " + A + "\"}"
		return shim.Error(jsonResp)
	}

	jsonResp := "{\"Name\":\"" + A + "\",\"Amount\":\"" + string(Avalbytes) + "\"}"
	fmt.Printf("Query Response:%s\n", jsonResp)
	return shim.Success(Avalbytes)
}

func main() {
	err := shim.Start(new(SimpleChaincode))
	if err != nil {
		fmt.Printf("Error starting Simple chaincode: %s", err)
	}
}