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這篇文章將為大家詳細講解有關Hyperledger Fabric中通過使用Node SDK來說明怎么與Blockchain進行交互，小編覺得挺實用的，因此分享給大家做個參考，希望大家閱讀完這篇文章后可以有所收獲。
由于Fabric是企業級的區塊鏈平臺， 對安全性要求極高， Fabric的所有請求都必須具有有效注冊證書的數字簽名。 其安全性是通過數字簽名來實現的， Fabric默認提供了一個可選的Fabric CA實現。
因此， 我們的客戶端實現也分為一下幾個步驟:
1 登記admin并獲取Fabric CA簽署的登記證書
'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 注冊用戶并獲取證書
'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 發送交易改變Blockchain狀態
'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 查詢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);
});關于“Hyperledger Fabric中通過使用Node SDK來說明怎么與Blockchain進行交互”這篇文章就分享到這里了，希望以上內容可以對大家有一定的幫助，使各位可以學到更多知識，如果覺得文章不錯，請把它分享出去讓更多的人看到。
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