这篇文章将为大家详细讲解有关Hyperledger Fabric中通过使用Node SDK来说明怎么与Blockchain进行交互,小编觉得挺实用的,因此分享给大家做个参考,希望大家阅读完这篇文章后可以有所收获。
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由于Fabric是企业级的区块链平台, 对安全性要求极高, Fabric的所有请求都必须具有有效注册证书的数字签名。 其安全性是通过数字签名来实现的, Fabric默认提供了一个可选的Fabric CA实现。
因此, 我们的客户端实现也分为一下几个步骤:
1 登记admin并获取Fabric CA签署的登记证书
'use strict'; /* * Copyright IBM Corp All Rights Reserved * * SPDX-License-Identifier: Apache-2.0 */ /* * Chaincode Invoke */ var Fabric_Client = require('fabric-client'); var path = require('path'); var util = require('util'); var os = require('os'); // var fabric_client = new Fabric_Client(); // setup the fabric network var channel = fabric_client.newChannel('mychannel'); var peer = fabric_client.newPeer('grpc://localhost:7051'); channel.addPeer(peer); var order = fabric_client.newOrderer('grpc://localhost:7050') channel.addOrderer(order); // var member_user = null; var store_path = path.join(__dirname, 'hfc-key-store'); console.log('Store path:'+store_path); var tx_id = null; // create the key value store as defined in the fabric-client/config/default.json 'key-value-store' setting Fabric_Client.newDefaultKeyValueStore({ path: store_path }).then((state_store) => { // assign the store to the fabric client fabric_client.setStateStore(state_store); var crypto_suite = Fabric_Client.newCryptoSuite(); // use the same location for the state store (where the users' certificate are kept) // and the crypto store (where the users' keys are kept) var crypto_store = Fabric_Client.newCryptoKeyStore({path: store_path}); crypto_suite.setCryptoKeyStore(crypto_store); fabric_client.setCryptoSuite(crypto_suite); // get the enrolled user from persistence, this user will sign all requests return fabric_client.getUserContext('user1', true); }).then((user_from_store) => { if (user_from_store && user_from_store.isEnrolled()) { console.log('Successfully loaded user1 from persistence'); member_user = user_from_store; } else { throw new Error('Failed to get user1.... run registerUser.js'); } // get a transaction id object based on the current user assigned to fabric client tx_id = fabric_client.newTransactionID(); console.log("Assigning transaction_id: ", tx_id._transaction_id); // createCar chaincode function - requires 5 args, ex: args: ['CAR12', 'Honda', 'Accord', 'Black', 'Tom'], // changeCarOwner chaincode function - requires 2 args , ex: args: ['CAR10', 'Dave'], // must send the proposal to endorsing peers var request = { //targets: let default to the peer assigned to the client chaincodeId: 'fabcar', fcn: '', args: [''], chainId: 'mychannel', txId: tx_id }; // send the transaction proposal to the peers return channel.sendTransactionProposal(request); }).then((results) => { var proposalResponses = results[0]; var proposal = results[1]; let isProposalGood = false; if (proposalResponses && proposalResponses[0].response && proposalResponses[0].response.status === 200) { isProposalGood = true; console.log('Transaction proposal was good'); } else { console.error('Transaction proposal was bad'); } if (isProposalGood) { console.log(util.format( 'Successfully sent Proposal and received ProposalResponse: Status - %s, message - "%s"', proposalResponses[0].response.status, proposalResponses[0].response.message)); // build up the request for the orderer to have the transaction committed var request = { proposalResponses: proposalResponses, proposal: proposal }; // set the transaction listener and set a timeout of 30 sec // if the transaction did not get committed within the timeout period, // report a TIMEOUT status var transaction_id_string = tx_id.getTransactionID(); //Get the transaction ID string to be used by the event processing var promises = []; var sendPromise = channel.sendTransaction(request); promises.push(sendPromise); //we want the send transaction first, so that we know where to check status // get an eventhub once the fabric client has a user assigned. The user // is required bacause the event registration must be signed let event_hub = fabric_client.newEventHub(); event_hub.setPeerAddr('grpc://localhost:7053'); // using resolve the promise so that result status may be processed // under the then clause rather than having the catch clause process // the status let txPromise = new Promise((resolve, reject) => { let handle = setTimeout(() => { event_hub.disconnect(); resolve({event_status : 'TIMEOUT'}); //we could use reject(new Error('Trnasaction did not complete within 30 seconds')); }, 3000); event_hub.connect(); event_hub.registerTxEvent(transaction_id_string, (tx, code) => { // this is the callback for transaction event status // first some clean up of event listener clearTimeout(handle); event_hub.unregisterTxEvent(transaction_id_string); event_hub.disconnect(); // now let the application know what happened var return_status = {event_status : code, tx_id : transaction_id_string}; if (code !== 'VALID') { console.error('The transaction was invalid, code = ' + code); resolve(return_status); // we could use reject(new Error('Problem with the tranaction, event status ::'+code)); } else { console.log('The transaction has been committed on peer ' + event_hub._ep._endpoint.addr); resolve(return_status); } }, (err) => { //this is the callback if something goes wrong with the event registration or processing reject(new Error('There was a problem with the eventhub ::'+err)); }); }); promises.push(txPromise); return Promise.all(promises); } else { console.error('Failed to send Proposal or receive valid response. Response null or status is not 200. exiting...'); throw new Error('Failed to send Proposal or receive valid response. Response null or status is not 200. exiting...'); } }).then((results) => { console.log('Send transaction promise and event listener promise have completed'); // check the results in the order the promises were added to the promise all list if (results && results[0] && results[0].status === 'SUCCESS') { console.log('Successfully sent transaction to the orderer.'); } else { console.error('Failed to order the transaction. Error code: ' + results[0].status); } if(results && results[1] && results[1].event_status === 'VALID') { console.log('Successfully committed the change to the ledger by the peer'); } else { console.log('Transaction failed to be committed to the ledger due to ::'+results[1].event_status); } }).catch((err) => { console.error('Failed to invoke successfully :: ' + err); });
2 注册用户并获取证书
'use strict'; /* * Copyright IBM Corp All Rights Reserved * * SPDX-License-Identifier: Apache-2.0 */ /* * Register and Enroll a user */ var Fabric_Client = require('fabric-client'); var Fabric_CA_Client = require('fabric-ca-client'); var path = require('path'); var util = require('util'); var os = require('os'); // var fabric_client = new Fabric_Client(); var fabric_ca_client = null; var admin_user = null; var member_user = null; var store_path = path.join(__dirname, 'hfc-key-store'); console.log(' Store path:'+store_path); // create the key value store as defined in the fabric-client/config/default.json 'key-value-store' setting Fabric_Client.newDefaultKeyValueStore({ path: store_path }).then((state_store) => { // assign the store to the fabric client fabric_client.setStateStore(state_store); var crypto_suite = Fabric_Client.newCryptoSuite(); // use the same location for the state store (where the users' certificate are kept) // and the crypto store (where the users' keys are kept) var crypto_store = Fabric_Client.newCryptoKeyStore({path: store_path}); crypto_suite.setCryptoKeyStore(crypto_store); fabric_client.setCryptoSuite(crypto_suite); var tlsOptions = { trustedRoots: [], verify: false }; // be sure to change the http to https when the CA is running TLS enabled fabric_ca_client = new Fabric_CA_Client('http://localhost:7054', null , '', crypto_suite); // first check to see if the admin is already enrolled return fabric_client.getUserContext('admin', true); }).then((user_from_store) => { if (user_from_store && user_from_store.isEnrolled()) { console.log('Successfully loaded admin from persistence'); admin_user = user_from_store; } else { throw new Error('Failed to get admin.... run enrollAdmin.js'); } // at this point we should have the admin user // first need to register the user with the CA server return fabric_ca_client.register({enrollmentID: 'user1', affiliation: 'org1.department1',role: 'client'}, admin_user); }).then((secret) => { // next we need to enroll the user with CA server console.log('Successfully registered user1 - secret:'+ secret); return fabric_ca_client.enroll({enrollmentID: 'user1', enrollmentSecret: secret}); }).then((enrollment) => { console.log('Successfully enrolled member user "user1" '); return fabric_client.createUser( {username: 'user1', mspid: 'Org1MSP', cryptoContent: { privateKeyPEM: enrollment.key.toBytes(), signedCertPEM: enrollment.certificate } }); }).then((user) => { member_user = user; return fabric_client.setUserContext(member_user); }).then(()=>{ console.log('User1 was successfully registered and enrolled and is ready to interact with the fabric network'); }).catch((err) => { console.error('Failed to register: ' + err); if(err.toString().indexOf('Authorization') > -1) { console.error('Authorization failures may be caused by having admin credentials from a previous CA instance.\n' + 'Try again after deleting the contents of the store directory '+store_path); } });
3 发送交易改变Blockchain状态
'use strict'; /* * Chaincode Invoke */ var Fabric_Client = require('fabric-client'); var path = require('path'); var util = require('util'); var os = require('os'); // var fabric_client = new Fabric_Client(); // setup the fabric network var channel = fabric_client.newChannel('mychannel'); var peer = fabric_client.newPeer('grpc://localhost:7051'); channel.addPeer(peer); var order = fabric_client.newOrderer('grpc://localhost:7050') channel.addOrderer(order); // var member_user = null; var store_path = path.join(__dirname, 'hfc-key-store'); console.log('Store path:'+store_path); var tx_id = null; // create the key value store as defined in the fabric-client/config/default.json 'key-value-store' setting Fabric_Client.newDefaultKeyValueStore({ path: store_path }).then((state_store) => { // assign the store to the fabric client fabric_client.setStateStore(state_store); var crypto_suite = Fabric_Client.newCryptoSuite(); // use the same location for the state store (where the users' certificate are kept) // and the crypto store (where the users' keys are kept) var crypto_store = Fabric_Client.newCryptoKeyStore({path: store_path}); crypto_suite.setCryptoKeyStore(crypto_store); fabric_client.setCryptoSuite(crypto_suite); // get the enrolled user from persistence, this user will sign all requests return fabric_client.getUserContext('user1', true); }).then((user_from_store) => { if (user_from_store && user_from_store.isEnrolled()) { console.log('Successfully loaded user1 from persistence'); member_user = user_from_store; } else { throw new Error('Failed to get user1.... run registerUser.js'); } // get a transaction id object based on the current user assigned to fabric client tx_id = fabric_client.newTransactionID(); console.log("Assigning transaction_id: ", tx_id._transaction_id); // createCar chaincode function - requires 5 args, ex: args: ['CAR12', 'Honda', 'Accord', 'Black', 'Tom'], // changeCarOwner chaincode function - requires 2 args , ex: args: ['CAR10', 'Dave'], // must send the proposal to endorsing peers var request = { //targets: let default to the peer assigned to the client chaincodeId: 'fabcar', fcn: '', args: [''], chainId: 'mychannel', txId: tx_id }; // send the transaction proposal to the peers return channel.sendTransactionProposal(request); }).then((results) => { var proposalResponses = results[0]; var proposal = results[1]; let isProposalGood = false; if (proposalResponses && proposalResponses[0].response && proposalResponses[0].response.status === 200) { isProposalGood = true; console.log('Transaction proposal was good'); } else { console.error('Transaction proposal was bad'); } if (isProposalGood) { console.log(util.format( 'Successfully sent Proposal and received ProposalResponse: Status - %s, message - "%s"', proposalResponses[0].response.status, proposalResponses[0].response.message)); // build up the request for the orderer to have the transaction committed var request = { proposalResponses: proposalResponses, proposal: proposal }; // set the transaction listener and set a timeout of 30 sec // if the transaction did not get committed within the timeout period, // report a TIMEOUT status var transaction_id_string = tx_id.getTransactionID(); //Get the transaction ID string to be used by the event processing var promises = []; var sendPromise = channel.sendTransaction(request); promises.push(sendPromise); //we want the send transaction first, so that we know where to check status // get an eventhub once the fabric client has a user assigned. The user // is required bacause the event registration must be signed let event_hub = fabric_client.newEventHub(); event_hub.setPeerAddr('grpc://localhost:7053'); // using resolve the promise so that result status may be processed // under the then clause rather than having the catch clause process // the status let txPromise = new Promise((resolve, reject) => { let handle = setTimeout(() => { event_hub.disconnect(); resolve({event_status : 'TIMEOUT'}); //we could use reject(new Error('Trnasaction did not complete within 30 seconds')); }, 3000); event_hub.connect(); event_hub.registerTxEvent(transaction_id_string, (tx, code) => { // this is the callback for transaction event status // first some clean up of event listener clearTimeout(handle); event_hub.unregisterTxEvent(transaction_id_string); event_hub.disconnect(); // now let the application know what happened var return_status = {event_status : code, tx_id : transaction_id_string}; if (code !== 'VALID') { console.error('The transaction was invalid, code = ' + code); resolve(return_status); // we could use reject(new Error('Problem with the tranaction, event status ::'+code)); } else { console.log('The transaction has been committed on peer ' + event_hub._ep._endpoint.addr); resolve(return_status); } }, (err) => { //this is the callback if something goes wrong with the event registration or processing reject(new Error('There was a problem with the eventhub ::'+err)); }); }); promises.push(txPromise); return Promise.all(promises); } else { console.error('Failed to send Proposal or receive valid response. Response null or status is not 200. exiting...'); throw new Error('Failed to send Proposal or receive valid response. Response null or status is not 200. exiting...'); } }).then((results) => { console.log('Send transaction promise and event listener promise have completed'); // check the results in the order the promises were added to the promise all list if (results && results[0] && results[0].status === 'SUCCESS') { console.log('Successfully sent transaction to the orderer.'); } else { console.error('Failed to order the transaction. Error code: ' + results[0].status); } if(results && results[1] && results[1].event_status === 'VALID') { console.log('Successfully committed the change to the ledger by the peer'); } else { console.log('Transaction failed to be committed to the ledger due to ::'+results[1].event_status); } }).catch((err) => { console.error('Failed to invoke successfully :: ' + err); });
4 查询Blockchain
'use strict'; /* * Chaincode query */ var Fabric_Client = require('fabric-client'); var path = require('path'); var util = require('util'); var os = require('os'); // var fabric_client = new Fabric_Client(); // setup the fabric network var channel = fabric_client.newChannel('mychannel'); var peer = fabric_client.newPeer('grpc://localhost:7051'); channel.addPeer(peer); // var member_user = null; var store_path = path.join(__dirname, 'hfc-key-store'); console.log('Store path:'+store_path); var tx_id = null; // create the key value store as defined in the fabric-client/config/default.json 'key-value-store' setting Fabric_Client.newDefaultKeyValueStore({ path: store_path }).then((state_store) => { // assign the store to the fabric client fabric_client.setStateStore(state_store); var crypto_suite = Fabric_Client.newCryptoSuite(); // use the same location for the state store (where the users' certificate are kept) // and the crypto store (where the users' keys are kept) var crypto_store = Fabric_Client.newCryptoKeyStore({path: store_path}); crypto_suite.setCryptoKeyStore(crypto_store); fabric_client.setCryptoSuite(crypto_suite); // get the enrolled user from persistence, this user will sign all requests return fabric_client.getUserContext('user1', true); }).then((user_from_store) => { if (user_from_store && user_from_store.isEnrolled()) { console.log('Successfully loaded user1 from persistence'); member_user = user_from_store; } else { throw new Error('Failed to get user1.... run registerUser.js'); } // queryCar chaincode function - requires 1 argument, ex: args: ['CAR4'], // queryAllCars chaincode function - requires no arguments , ex: args: [''], const request = { //targets : --- letting this default to the peers assigned to the channel chaincodeId: 'fabcar', fcn: 'queryAllCars', args: [''] }; // send the query proposal to the peer return channel.queryByChaincode(request); }).then((query_responses) => { console.log("Query has completed, checking results"); // query_responses could have more than one results if there multiple peers were used as targets if (query_responses && query_responses.length == 1) { if (query_responses[0] instanceof Error) { console.error("error from query = ", query_responses[0]); } else { console.log("Response is ", query_responses[0].toString()); } } else { console.log("No payloads were returned from query"); } }).catch((err) => { console.error('Failed to query successfully :: ' + err); });
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