Hyperledger Fabric 1.0 实战开发系列 第四课 搭建node.js服务器
接下来我要做的是用fabric sdk来做出应用程序，代替CLI与整个区块链网络交互。并且实现一个http API，向社区提供一个简单的接口，使社区轻松的与区块链交互。
官方虽然提供了Node.JS，Java，Go（最近刚出了python）等多种语言的SDK，但是很多SDK还不成熟和完善，有的甚至文档都没有。我使用Node.js的原因有二。1.官方例子使用的是Node.js SDK 2.因为Node.js实现一个http服务器是非常简单的。
我们可以选择将node.js安装在本地，或者将node应用部署在docker。需要注意的是fabric目前不支持node7.x版本，需要6.9.x或更高版本和NPM。
一、下载nodejs
1.下载node.js，由于node服务器在国外 所以需要下载，在Terminal中输入以下命令：
wget https://nodejs.org/download/release/v6.10.0/node-v6.10.0-linux-x64.tar.gz
2、下载下来的tar文件上传到服务器并且解压，然后通过建立软连接变为全局；
1）上传服务器可以是自己任意路径，目前我的放置路径为 /usr/local
2）解压上传（解压后的文件我这边将名字改为了nodejs，这个地方自己随意，只要在建立软连接的时候写正确就可以）
① tar -xvf node-v6.10.0-linux-x64.tar.xz
② mv node-v6.10.0-linux-x64 nodejs
③确认一下nodejs下bin目录是否有node 和npm文件，如果有执行软连接，如果没有重新下载执行上边步骤；
3）建立软连接，变为全局
①ln -s /usr/local/nodejs/bin/npm /usr/local/bin/
②ln -s /usr/local/nodejs/bin/node /usr/local/bin/
4）最后一步检验nodejs是否已变为全局
在Linux命令行node -v 命令会显示nodejs版本，如图所示为大功告成
二.创建node.js程序
1.编写package.json并下载依赖模块
我们首先在当前用户的根目录建立一个nodeTest的文件夹，用于存放我们关于node的相关项目文件，然后在其中新建一个包配置文件，package.json
mkdir ~/nodeTest
cd ~/nodeTest
vi package.json
在这个文件中，我们可以定义很多项目相关的属性，这篇博客详细的介绍了每个属性有什么用，大家可以参考：http://www.cnblogs.com/tzyy/p/5193811.html
总之，最后我们在package.json中放入了以下内容：
{
"name": "nodeTest",
"version": "1.0.0",
"description": "Hyperledger Fabric Node SDK Test Application",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"dependencies": {
"fabric-ca-client": "^1.0.0",
"fabric-client": "^1.0.0"
},
"author": "Devin Zeng",
"license": "Apache-2.0",
"keywords": [
"Hyperledger",
"Fabric",
"Test",
"Application"
]
}
最主要的就是dependencies，这里我们放了Fabric CA Client和Fabric Node SDK的Client，虽然本示例中没用到CA Client，但是以后会用到，所以先放在这里了。
编辑保存好该文件后，我们就可以运行npm install命令来下载所有相关的依赖模块，但是由于npm服务器在国外，所以下载可能会很慢，感谢淘宝为我们提供了国内的npm镜像，使得安装npm模块快很多。运行的命令是：npm install --registry=https://registry.npm.taobao.org
运行完毕后我们查看一下nodeTest目录，可以看到多了一个node_modules文件夹。这里就是使用刚才的命令下载下来的所有依赖包。
2.编写对Fabric的Query方法
下面我们新建一个query.js文件，开始我们的Fabric Node SDK编码工作。由于代码比较长，所以我就不分步讲了，直接在代码中增加注释，将完整代码贴出来：
'use strict';
var hfc = require('fabric-client');
var path = require('path');
var sdkUtils = require('fabric-client/lib/utils')
var fs = require('fs');
var options = {
user_id: '[email protected]',
msp_id:'Org1MSP',
channel_id: 'mychannel',
chaincode_id: 'mycc',
network_url: 'grpcs://localhost:7051',//因为启用了TLS，所以是grpcs,如果没有启用TLS，那么就是grpc
privateKeyFolder:'/home/studyzy/go/src/github.com/hyperledger/fabric/examples/e2e_cli/crypto-config/peerOrganizations/org1.example.com/users/[email protected]/msp/keystore',
signedCert:'/home/studyzy/go/src/github.com/hyperledger/fabric/examples/e2e_cli/crypto-config/peerOrganizations/org1.example.com/users/[email protected]/msp/signcerts/[email protected]',
tls_cacerts:'/home/studyzy/go/src/github.com/hyperledger/fabric/examples/e2e_cli/crypto-config/peerOrganizations/org1.example.com/peers/peer0.org1.example.com/tls/ca.crt',
server_hostname: "peer0.org1.example.com"
};
var channel = {};
var client = null;
const getKeyFilesInDir = (dir) => {
//该函数用于找到keystore目录下的私钥文件的路径
var files = fs.readdirSync(dir)
var keyFiles = []
files.forEach((file_name) => {
let filePath = path.join(dir, file_name)
if (file_name.endsWith('_sk')) {
keyFiles.push(filePath)
}
})
return keyFiles
}
Promise.resolve().then(() => {
console.log("Load privateKey and signedCert");
client = new hfc();
var createUserOpt = {
username: options.user_id,
mspid: options.msp_id,
cryptoContent: { privateKey: getKeyFilesInDir(options.privateKeyFolder)[0],
signedCert: options.signedCert }
}
//以上代码指定了当前用户的私钥，证书等基本信息
return sdkUtils.newKeyValueStore({
path: "/tmp/fabric-client-stateStore/"
}).then((store) => {
client.setStateStore(store)
return client.createUser(createUserOpt)
})
}).then((user) => {
channel = client.newChannel(options.channel_id);
let data = fs.readFileSync(options.tls_cacerts);
let peer = client.newPeer(options.network_url,
{
pem: Buffer.from(data).toString(),
'ssl-target-name-override': options.server_hostname
}
);
peer.setName("peer0");
//因为启用了TLS，所以上面的代码就是指定TLS的CA证书
channel.addPeer(peer);
return;
}).then(() => {
console.log("Make query");
var transaction_id = client.newTransactionID();
console.log("Assigning transaction_id: ", transaction_id._transaction_id);
//构造查询request参数
const request = {
chaincodeId: options.chaincode_id,
txId: transaction_id,
fcn: 'query',
args: ['a']
};
return channel.queryByChaincode(request);
}).then((query_responses) => {
console.log("returned from query");
if (!query_responses.length) {
console.log("No payloads were returned from query");
} else {
console.log("Query result count = ", query_responses.length)
}
if (query_responses[0] instanceof Error) {
console.error("error from query = ", query_responses[0]);
}
console.log("Response is ", query_responses[0].toString());//打印返回的结果
}).catch((err) => {
console.error("Caught Error", err);
});
编写完代码，我们想要测试一下我们的代码是否靠谱，直接运行
node query.js
即可，我们可以看到，a账户的余额是90元。
studyzy@ubuntu1:~/nodeTest$ node query.js
Load privateKey and signedCert
Make query
Assigning transaction_id: ee3ac35d40d8510813546a2216ad9c0d91213b8e1bba9b7fe19cfeff3014e38a
returned from query
Query result count = 1
Response is 90
为什么a账户是90？因为我们跑e2e_cli的Fabric网络时，系统会自动安装Example02的ChainCode，然后自动跑查询，转账等操作。
3.编写对Fabric的Invoke方法
相比较于Query方法，Invoke方法要复杂的多，主要是因为Invoke需要和Orderer通信，而且发起了Transaction之后，还要设置EventHub来接收消息。下面贴出invoke.js的全部内容，对于比较重要的部分我进行了注释:
'use strict';
var hfc = require('fabric-client');
var path = require('path');
var util = require('util');
var sdkUtils = require('fabric-client/lib/utils')
const fs = require('fs');
var options = {
user_id: '[email protected]',
msp_id:'Org1MSP',
channel_id: 'mychannel',
chaincode_id: 'mycc',
peer_url: 'grpcs://localhost:7051',//因为启用了TLS，所以是grpcs,如果没有启用TLS，那么就是grpc
event_url: 'grpcs://localhost:7053',//因为启用了TLS，所以是grpcs,如果没有启用TLS，那么就是grpc
orderer_url: 'grpcs://localhost:7050',//因为启用了TLS，所以是grpcs,如果没有启用TLS，那么就是grpc
privateKeyFolder:'/home/studyzy/go/src/github.com/hyperledger/fabric/examples/e2e_cli/crypto-config/peerOrganizations/org1.example.com/users/[email protected]/msp/keystore',
signedCert:'/home/studyzy/go/src/github.com/hyperledger/fabric/examples/e2e_cli/crypto-config/peerOrganizations/org1.example.com/users/[email protected]/msp/signcerts/[email protected]',
peer_tls_cacerts:'/home/studyzy/go/src/github.com/hyperledger/fabric/examples/e2e_cli/crypto-config/peerOrganizations/org1.example.com/peers/peer0.org1.example.com/tls/ca.crt',
orderer_tls_cacerts:'/home/studyzy/go/src/github.com/hyperledger/fabric/examples/e2e_cli/crypto-config/ordererOrganizations/example.com/orderers/orderer.example.com/tls/ca.crt',
server_hostname: "peer0.org1.example.com"
};
var channel = {};
var client = null;
var targets = [];
var tx_id = null;
const getKeyFilesInDir = (dir) => {
//该函数用于找到keystore目录下的私钥文件的路径
const files = fs.readdirSync(dir)
const keyFiles = []
files.forEach((file_name) => {
let filePath = path.join(dir, file_name)
if (file_name.endsWith('_sk')) {
keyFiles.push(filePath)
}
})
return keyFiles
}
Promise.resolve().then(() => {
console.log("Load privateKey and signedCert");
client = new hfc();
var createUserOpt = {
username: options.user_id,
mspid: options.msp_id,
cryptoContent: { privateKey: getKeyFilesInDir(options.privateKeyFolder)[0],
signedCert: options.signedCert }
}
//以上代码指定了当前用户的私钥，证书等基本信息
return sdkUtils.newKeyValueStore({
path: "/tmp/fabric-client-stateStore/"
}).then((store) => {
client.setStateStore(store)
return client.createUser(createUserOpt)
})
}).then((user) => {
channel = client.newChannel(options.channel_id);
let data = fs.readFileSync(options.peer_tls_cacerts);
let peer = client.newPeer(options.peer_url,
{
pem: Buffer.from(data).toString(),
'ssl-target-name-override': options.server_hostname
}
);
//因为启用了TLS，所以上面的代码就是指定Peer的TLS的CA证书
channel.addPeer(peer);
//接下来连接Orderer的时候也启用了TLS，也是同样的处理方法
let odata = fs.readFileSync(options.orderer_tls_cacerts);
let caroots = Buffer.from(odata).toString();
var orderer = client.newOrderer(options.orderer_url, {
'pem': caroots,
'ssl-target-name-override': "orderer.example.com"
});
channel.addOrderer(orderer);
targets.push(peer);
return;
}).then(() => {
tx_id = client.newTransactionID();
console.log("Assigning transaction_id: ", tx_id._transaction_id);
//发起转账行为，将a->b 10元
var request = {
targets: targets,
chaincodeId: options.chaincode_id,
fcn: 'invoke',
args: ['a', 'b', '10'],
chainId: options.channel_id,
txId: tx_id
};
return channel.sendTransactionProposal(request);
}).then((results) => {
var proposalResponses = results[0];
var proposal = results[1];
var header = results[2];
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", metadata - "%s", endorsement signature: %s',
proposalResponses[0].response.status, proposalResponses[0].response.message,
proposalResponses[0].response.payload, proposalResponses[0].endorsement.signature));
var request = {
proposalResponses: proposalResponses,
proposal: proposal,
header: header
};
// set the transaction listener and set a timeout of 30sec
// if the transaction did not get committed within the timeout period,
// fail the test
var transactionID = tx_id.getTransactionID();
var eventPromises = [];
let eh = client.newEventHub();
//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(options.peer_tls_cacerts);
let grpcOpts = {
pem: Buffer.from(data).toString(),
'ssl-target-name-override': options.server_hostname
}
eh.setPeerAddr(options.event_url,grpcOpts);
eh.connect();
let txPromise = new Promise((resolve, reject) => {
let handle = setTimeout(() => {
eh.disconnect();
reject();
}, 30000);
//向EventHub注册事件的处理办法
eh.registerTxEvent(transactionID, (tx, code) => {
clearTimeout(handle);
eh.unregisterTxEvent(transactionID);
eh.disconnect();
if (code !== 'VALID') {
console.error(
'The transaction was invalid, code = ' + code);
reject();
} else {
console.log(
'The transaction has been committed on peer ' +
eh._ep._endpoint.addr);
resolve();
}
});
});
eventPromises.push(txPromise);
var sendPromise = channel.sendTransaction(request);
return Promise.all([sendPromise].concat(eventPromises)).then((results) => {
console.log(' event promise all complete and testing complete');
return results[0]; // the first returned value is from the 'sendPromise' which is from the 'sendTransaction()' call
}).catch((err) => {
console.error(
'Failed to send transaction and get notifications within the timeout period.'
);
return 'Failed to send transaction and get notifications within the timeout period.';
});
} else {
console.error(
'Failed to send Proposal or receive valid response. Response null or status is not 200. exiting...'
);
return 'Failed to send Proposal or receive valid response. Response null or status is not 200. exiting...';
}
}, (err) => {
console.error('Failed to send proposal due to error: ' + err.stack ? err.stack :
err);
return 'Failed to send proposal due to error: ' + err.stack ? err.stack :
err;
}).then((response) => {
if (response.status === 'SUCCESS') {
console.log('Successfully sent transaction to the orderer.');
return tx_id.getTransactionID();
} else {
console.error('Failed to order the transaction. Error code: ' + response.status);
return 'Failed to order the transaction. Error code: ' + response.status;
}
}, (err) => {
console.error('Failed to send transaction due to error: ' + err.stack ? err
.stack : err);
return 'Failed to send transaction due to error: ' + err.stack ? err.stack :
err;
});
cd fabric-samples/balance-transfer/docker-compose -f artifacts/docker-compose.yaml upLogin Request
- Register and enroll new users in Organization - Org1:
- 在Termial中输入以下命令
curl -s -X POST http://localhost:4000/users -H "content-type: application/x-www-form-urlencoded" -d 'username=Jim&orgName=org1'
OUTPUT:
{
"success": true,
"secret": "RaxhMgevgJcm",
"message": "Jim enrolled Successfully",
"token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE0OTQ4NjU1OTEsInVzZXJuYW1lIjoiSmltIiwib3JnTmFtZSI6Im9yZzEiLCJpYXQiOjE0OTQ4NjE5OTF9.yWaJhFDuTvMQRaZIqg20Is5t-JJ_1BP58yrNLOKxtNI"
}
四.总结
这只是简单的测试Node SDK是否可用，如果我们要做项目，那么就会复杂很多，可以参考官方的两个项目：
https://github.com/hyperledger/fabric-samples/tree/release/balance-transfer
https://github.com/IBM-Blockchain/marbles