基于hyperledger fabric 联盟链 + vue cli的项目搭建完整教程
五、基于fabric-node-sdk后端代码搭建
在完成了链码的撰写和部署安装实例化之后，我们开始koa后端搭建
1. fabric区块链查询nodejs代码
基础思路是调用node-sdk的queryChaincode方法
async searchAllTrail ( ctx ) {
const title = 'admin page'
let result = ''
var fabric_client = new Fabric_Client();
var key = "name"
// 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(os.homedir(), '.hfc-key-store');
var store_path = path.join('/home/fabric/Documents/carChain/app/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
result = await 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');
}
// queryTuna - requires 1 argument, ex: args: ['4'],
const request = {
chaincodeId: 'trail',
txId: tx_id,
fcn: 'searchAllTrail',
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]);
result = "Could not locate tuna"
} else {
console.log("Response is ", query_responses[0].toString());
return query_responses[0].toString()
}
} else {
console.log("No payloads were returned from query");
result = "Could not locate tuna"
}
}).catch((err) => {
console.error('Failed to query successfully :: ' + err);
result = 'Failed to query successfully :: ' + err
});
// await ctx.render('index', {
// title, result
// })
ctx.body = result
},
2. fabric区块链修改（插入,删除）nodejs代码
基础思路是调用node-sdk的sendTransactionProposal()方法提交提案和sendTransaction()执行区块链账本存储，执行PutState操作，再在Order队列中进行校验
async insertTrail (ctx) {
const queryBody = ctx.request.query;
const Trid = queryBody.Trid;
console.log(`Trid.....${
Trid}`)
const jsonStr = queryBody.jsonStr;
console.log(`jsonStr.....${
jsonStr}`)
var fabric_client = new Fabric_Client();
// setup the fabric network
var channel = fabric_client.newChannel('mychannel');
var peer = fabric_client.newPeer('grpc://localhost:7051');
var order = fabric_client.newOrderer('grpc://localhost:7050')
channel.addOrderer(order);
channel.addPeer(peer);
var member_user = null;
// var store_path = path.join(os.homedir(), '.hfc-key-store');
var store_path = path.join('/home/fabric/Documents/carChain/app/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
let result = await 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);
// recordTuna - requires 5 args, ID, vessel, location, timestamp,holder - ex: args: ['10', 'Hound', '-12.021, 28.012', '1504054225', 'Hansel'],
// send proposal to endorser
const request = {
//targets : --- letting this default to the peers assigned to the channel
chaincodeId: 'trail',
fcn: 'insertTrail',
args : [Trid,jsonStr],
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('grpc://localhost:7053');
// // let event_hub = new ChannelEventHub(channel, peer);
// //接下来设置EventHub，用于监听Transaction是否成功写入，这里也是启用了TLS
// let data = fs.readFileSync('/home/fabric/Documents/carChain/basic-network/crypto-config/peerOrganizations/org1.example.com/peers/peer0.org1.example.com/tls/ca.crt');
// let grpcOpts = {
// 'pem': Buffer.from(data).toString(),
// 'ssl-target-name-override': "peer0.org1.example.com"
// }
// event_hub.setPeerAddr('grpc://localhost:7053',grpcOpts);
// event_hub.connect();
// console.log('data:'+data);
// console.log('grpcOpts.pem:'+grpcOpts.pem);
//------------------------------------------------------------
let event_hub = channel.newChannelEventHub('localhost:7051');
//------------------------------------------------------------
// 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);
//-------------------------------------------------------------------------------------------
console.log('The transaction has been committed on peer ' + event_hub.getPeerAddr());
//-------------------------------------------------------------------------------------------
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.');
//res.send(tx_id.getTransactionID());
return tx_id.getTransactionID();
} else {
console.error('Failed to order the transaction. Error code: ' + response.status);
}
if(results && results[1] && results[1].event_status === 'VALID') {
console.log('Successfully committed the change to the ledger by the peer');
//res.send(tx_id.getTransactionID());
return tx_id.getTransactionID();
} 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);
});
ctx.body = result
},
3. 配置路由
const router = require('koa-router')()
const IndexController = require('./../controllers/index')
router
// .get('/',IndexController.indexPage)
.get('/saveUser', IndexController.saveUser)
.get('/insertTrail',IndexController.insertTrail)
.get('/searchAllTrail',IndexController.searchAllTrail)
.get('/searchOneTrail',IndexController.searchOneTrail)
.get('/deleteTrail',IndexController.deleteTrail)
4. Vue调用测试
插入轨迹
this.$http.get("http://localhost:3000/insertTrail",{
params: {
Trid : this.Trail.trid,
jsonStr : jsonStr
},
}).then(function(res){
console.log(res);
alert("交易hash tx_id: "+ res.data);
// location.reload()
});
查询轨迹
this.$http.get("http://localhost:3000/searchAllTrail", {
params: {
},
}).then(function(res){
console.log(res);
});
删除轨迹
this.$http.get("http://localhost:3000/deleteTrail", {
params: {
Trid : "002"
},
}).then(function(res){
console.log(res);
alert("删除交易hash tx_id: "+ res.data);
// location.reload()
});
插入数据之后访问http://localhost:5984/_utils/#/_all_dbs,点进CouchDB数据库网页端查看
vue前端查询
至此，基于fabric区块链的koa后端以及vue cli项目以及两者相关交互内容架构搭建已经完成