How to Delete All Cars form hyperledger Fabric and modify its arguments the chaincode and set the path to existing folder of chaincode

Question

i am still stuck in this problem since 2 days plz help to tell me how to  How to Delete All Cars form hyperledger Fabric and  modify its arguments the chaincode and set the path to existing folder of chaincode that is located in farbic-sample

Answer 1

First, you will have to make changes to the fabcar.go file. Do the changes such as deleting the cars and modifying arguments. After doing this, you have 3 ways to update it. 

1. Give a new name to the chaincode

peer chaincode install -n new_fabcar -v 1.0 -p github.com/fabcar

2. Give the same name that exists but with a increment version 

peer chaincode install -n fabcar -v 2.0 -p github.com/fabcar

3. Cleanup old chaincode container and install updated version of alternated chaincode over again. Something like this

docker images | grep fabcar | awk '{print $2}' | docker rmi

Comments

i modify the fabcar.go file and make 1 changes in startFabric.sh file but when i run startFabric.sh file then following error will be show

Error: could not assemble transaction, err proposal response was not successful, error code 500, msg transaction returned with failure: Incorrect arguments. Expecting a key and a value

fabcar.go file is following

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

/*
 * The sample smart contract for documentation topic:
 * Writing Your First Blockchain Application
 */

package main

/* Imports
 * 4 utility libraries for formatting, handling bytes, reading and writing JSON, and string manipulation
 * 2 specific Hyperledger Fabric specific libraries for Smart Contracts
 */
import (
    "bytes"
    "encoding/json"
    "fmt"
    "strconv"

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

// Define the Smart Contract structure
type SmartContract struct {
}

// Define the car structure, with 4 properties.  Structure tags are used by encoding/json library
type Car struct {
    Make   string `json:"make"`
    Model  string `json:"model"`
    Colour string `json:"colour"`
    Owner  string `json:"owner"`
}

/*
 * The Init method is called when the Smart Contract "fabcar" is instantiated by the blockchain network
 * Best practice is to have any Ledger initialization in separate function -- see initLedger()
 */
func (s *SmartContract) Init(APIstub shim.ChaincodeStubInterface) sc.Response {
    return shim.Success(nil)
}

/*
 * The Invoke method is called as a result of an application request to run the Smart Contract "fabcar"
 * The calling application program has also specified the particular smart contract function to be called, with arguments
 */
func (s *SmartContract) Invoke(APIstub shim.ChaincodeStubInterface) sc.Response {

    // Retrieve the requested Smart Contract function and arguments
    function, args := APIstub.GetFunctionAndParameters()
    // Route to the appropriate handler function to interact with the ledger appropriately
    if function == "queryCar" {
        return s.queryCar(APIstub, args)
    } else if function == "initLedger" {
        return s.initLedger(APIstub)
    } else if function == "createCar" {
        return s.createCar(APIstub, args)
    } else if function == "queryAllCars" {
        return s.queryAllCars(APIstub)
    } else if function == "changeCarOwner" {
        return s.changeCarOwner(APIstub, args)
    }

    return shim.Error("Invalid Smart Contract function name.")
}

func (s *SmartContract) queryCar(APIstub shim.ChaincodeStubInterface, args []string) sc.Response {

    if len(args) != 1 {
        return shim.Error("Incorrect number of arguments. Expecting 1")
    }

    carAsBytes, _ := APIstub.GetState(args[0])
    return shim.Success(carAsBytes)
}

func (s *SmartContract) initLedger(APIstub shim.ChaincodeStubInterface) sc.Response {
    cars := []Car{
        Car{Make: "Toyota", Model: "Prius", Colour: "blue", Owner: "Tomoko"},
       
    }

    i := 0
    for i < len(cars) {
        fmt.Println("i is ", i)
        carAsBytes, _ := json.Marshal(cars[i])
        APIstub.PutState("CAR"+strconv.Itoa(i), carAsBytes)
        fmt.Println("Added", cars[i])
        i = i + 1
    }

    return shim.Success(nil)
}

func (s *SmartContract) createCar(APIstub shim.ChaincodeStubInterface, args []string) sc.Response {

    if len(args) != 5 {
        return shim.Error("Incorrect number of arguments. Expecting 5")
    }

    var car = Car{Make: args[1], Model: args[2], Colour: args[3], Owner: args[4]}

    carAsBytes, _ := json.Marshal(car)
    APIstub.PutState(args[0], carAsBytes)

    return shim.Success(nil)
}

func (s *SmartContract) queryAllCars(APIstub shim.ChaincodeStubInterface) sc.Response {

    startKey := "CAR0"
    endKey := "CAR999"

    resultsIterator, err := APIstub.GetStateByRange(startKey, endKey)
    if err != nil {
        return shim.Error(err.Error())
    }
    defer resultsIterator.Close()

    // buffer is a JSON array containing QueryResults
    var buffer bytes.Buffer
    buffer.WriteString("[")

    bArrayMemberAlreadyWritten := false
    for resultsIterator.HasNext() {
        queryResponse, err := resultsIterator.Next()
        if err != nil {
            return shim.Error(err.Error())
        }
        // Add a comma before array members, suppress it for the first array member
        if bArrayMemberAlreadyWritten == true {
            buffer.WriteString(",")
        }
        buffer.WriteString("{\"Key\":")
        buffer.WriteString("\"")
        buffer.WriteString(queryResponse.Key)
        buffer.WriteString("\"")

        buffer.WriteString(", \"Record\":")
        // Record is a JSON object, so we write as-is
        buffer.WriteString(string(queryResponse.Value))
        buffer.WriteString("}")
        bArrayMemberAlreadyWritten = true
    }
    buffer.WriteString("]")

    fmt.Printf("- queryAllCars:\n%s\n", buffer.String())

    return shim.Success(buffer.Bytes())
}

func (s *SmartContract) changeCarOwner(APIstub shim.ChaincodeStubInterface, args []string) sc.Response {

    if len(args) != 2 {
        return shim.Error("Incorrect number of arguments. Expecting 2")
    }

    carAsBytes, _ := APIstub.GetState(args[0])
    car := Car{}

    json.Unmarshal(carAsBytes, &car)
    car.Owner = args[1]

    carAsBytes, _ = json.Marshal(car)
    APIstub.PutState(args[0], carAsBytes)

    return shim.Success(nil)
}

and startFabric.sh file is follwoing

#!/bin/bash
#
# Copyright IBM Corp All Rights Reserved
#
# SPDX-License-Identifier: Apache-2.0
#
# Exit on first error
set -e

# don't rewrite paths for Windows Git Bash users
export MSYS_NO_PATHCONV=1
starttime=$(date +%s)
LANGUAGE=${1:-"golang"}
CC_SRC_PATH=github.com/fabcar/go
if [ "$LANGUAGE" = "node" -o "$LANGUAGE" = "NODE" ]; then
    CC_SRC_PATH=/opt/gopath/src/github.com/fabcar/node
fi

# clean the keystore
rm -rf ./hfc-key-store

# launch network; create channel and join peer to channel
cd ../basic-network
./start.sh

# Now launch the CLI container in order to install, instantiate chaincode
# and prime the ledger with our 10 cars
docker-compose -f ./docker-compose.yml up -d cli

docker exec -e "CORE_PEER_LOCALMSPID=Org1MSP" -e "CORE_PEER_MSPCONFIGPATH=/opt/gopath/src/github.com/hyperledger/fabric/peer/crypto/peerOrganizations/org1.example.com/users/Admin@org1.example.com/msp" cli peer chaincode install -n new_fabcar -v 1.0 -p "$CC_SRC_PATH" -l "$LANGUAGE"
docker exec -e "CORE_PEER_LOCALMSPID=Org1MSP" -e "CORE_PEER_MSPCONFIGPATH=/opt/gopath/src/github.com/hyperledger/fabric/peer/crypto/peerOrganizations/org1.example.com/users/Admin@org1.example.com/msp" cli peer chaincode instantiate -o orderer.example.com:7050 -C mychannel -n new_fabcar -l "$LANGUAGE" -v 1.0 -c '{"Args":[""]}' -P "OR ('Org1MSP.member','Org2MSP.member')"
sleep 10
docker exec -e "CORE_PEER_LOCALMSPID=Org1MSP" -e "CORE_PEER_MSPCONFIGPATH=/opt/gopath/src/github.com/hyperledger/fabric/peer/crypto/peerOrganizations/org1.example.com/users/Admin@org1.example.com/msp" cli peer chaincode invoke -o orderer.example.com:7050 -C mychannel -n new_fabcar -c '{"function":"initLedger","Args":[""]}'

printf "\nTotal setup execution time : $(($(date +%s) - starttime)) secs ...\n\n\n"
printf "Start by installing required packages run 'npm install'\n"
printf "Then run 'node enrollAdmin.js', then 'node registerUser'\n\n"
printf "The 'node invoke.js' will fail until it has been updated with valid arguments\n"
printf "The 'node query.js' may be run at anytime once the user has been registered\n\n"

---

Could you please mention what changes you made? And also, I don't see the text "Incorrect arguments. Expecting a key and a value" in your code

---

i delete cars details default 10 cars records are store on hyperledger but i removed 9 cars now only one car detail should be store in hyperledger but its give me error

i modify follwoing function

func (s *SmartContract) initLedger(APIstub shim.ChaincodeStubInterface) sc.Response {
    cars := []Car{
        Car{Make: "Toyota", Model: "Prius", Colour: "blue", Owner: "Tomoko"},
       
    }

---

if i choose option 2 to version change in startFabric.sh file then follwoing error fabcar.go file is uploaded above plz help me

Error: could not assemble transaction, err proposal response was not successful, error code 500, msg error starting container: error starting container: Failed to generate platform-specific docker build: Error returned from build: 2 "# gith ub.com/fabcar/go runtime.main_main·f: relocation target main.main not defined runtime.main_main·f: undefined: "main.main"

---

The error says

Incorrect arguments. Expecting a key and a value

but I don't see where in the code you are printing this line. You have messages in code "Incorrect number of arguments. Expecting 2"

But the part of the code with "Expecting a key and a value" is missing.

Could you post that part of the code?

---

thank u so much bro i solved my problem i missed the mainfunction in fabcar.go file

---

I thought you had just missed posting it on the community so asked but in fact, it turned out to be thactually problem. :D