如何利用HyperledgerFabric的SDK来开发RESTAPI服务器
这篇文章主要为大家展示了“如何利用Hyperledger Fabric的SDK来开发REST API服务器”,内容简而易懂,条理清晰,希望能够帮助大家解决疑惑,下面让小编带领大家一起研究并学习一下“如何利用Hyperledger Fabric的SDK来开发REST API服务器”这篇文章吧。
目前创新互联已为成百上千的企业提供了网站建设、域名、网站空间、网站托管、服务器托管、企业网站设计、张湾网站维护等服务,公司将坚持客户导向、应用为本的策略,正道将秉承"和谐、参与、激情"的文化,与客户和合作伙伴齐心协力一起成长,共同发展。
1、系统结构概述
整个系统包含两个物理节点:
Fabric节点:运行Fabric示例中的First Network,并且实例化了Fabcar链码
API服务器节点:运行REST API Server代码供外部访问
下面是部署在AWS上的两个节点实例的情况:
首先参考官方文档安装hyperledger fabric。
然后运行脚本fabcar/startFabric.sh
:
cd fabric-samples/fabcar ./startFabric.sh
上述脚本运行之后,我们就得到一个正常运转的Hyperledger Fabric网络(著名的演示网络First Network),包含2个机构/4个对等节点,通道为mychannel,链码Fabcar安装在全部4个对等节点上并且在mychannel上激活。账本中有10条车辆记录,这是调用合约的initLedger
方法的结果。
现在我们为REST API Server准备身份标识数据。使用fabcar/javascript创建一个用户标识user1,我们将在REST API Server中使用这个身份标识:
cd javascript npm install node enrollAdmin.js node registerUser.js ls wallet/user1
运行结果如下:
现在Rest API Server需要的东西都备齐了:
org1的连接配置文件:first-network/connection-org1.json
Node.js包文件:fabcar/package.json
User1身份钱包:fabcar/javascript/wallet/user1/
后面我们会把这些数据文件拷贝到Rest API Server。
2、Rest API Server设计
我们使用ExressJS来开发API服务,利用query.js和invoke.js中的代码实现与fabric交互的逻辑。API设计如下:
GET /api/queryallcars:返回全部车辆记录
GET /api/query/CarID:返回指定ID的车辆记录
POST /api/addcar/:添加一条新的车辆记录
PUT /api/changeowner/CarID:修改指定ID的车辆记录
3、Rest API Server代码实现
apiserver.js代码如下:
var bodyParser = require('body-parser'); var app = express(); app.use(bodyParser.json()); // Setting for Hyperledger Fabric const { FileSystemWallet, Gateway } = require('fabric-network'); const path = require('path'); const ccpPath = path.resolve(__dirname, '.', 'connection-org1.json'); app.get('/api/queryallcars', async function (req, res) { try { // Create a new file system based wallet for managing identities. const walletPath = path.join(process.cwd(), 'wallet'); const wallet = new FileSystemWallet(walletPath); console.log(`Wallet path: ${walletPath}`); // Check to see if we've already enrolled the user. const userExists = await wallet.exists('user1'); if (!userExists) { console.log('An identity for the user "user1" does not exist in the wallet'); console.log('Run the registerUser.js application before retrying'); return; } // Create a new gateway for connecting to our peer node. const gateway = new Gateway(); await gateway.connect(ccpPath, { wallet, identity: 'user1', discovery: { enabled: true, asLocalhost: false } }); // Get the network (channel) our contract is deployed to. const network = await gateway.getNetwork('mychannel'); // Get the contract from the network. const contract = network.getContract('fabcar'); // Evaluate the specified transaction. // queryCar transaction - requires 1 argument, ex: ('queryCar', 'CAR4') // queryAllCars transaction - requires no arguments, ex: ('queryAllCars') const result = await contract.evaluateTransaction('queryAllCars'); console.log(`Transaction has been evaluated, result is: ${result.toString()}`); res.status(200).json({response: result.toString()}); } catch (error) { console.error(`Failed to evaluate transaction: ${error}`); res.status(500).json({error: error}); process.exit(1); } }); app.get('/api/query/:car_index', async function (req, res) { try { // Create a new file system based wallet for managing identities. const walletPath = path.join(process.cwd(), 'wallet'); const wallet = new FileSystemWallet(walletPath); console.log(`Wallet path: ${walletPath}`); // Check to see if we've already enrolled the user. const userExists = await wallet.exists('user1'); if (!userExists) { console.log('An identity for the user "user1" does not exist in the wallet'); console.log('Run the registerUser.js application before retrying'); return; } // Create a new gateway for connecting to our peer node. const gateway = new Gateway(); await gateway.connect(ccpPath, { wallet, identity: 'user1', discovery: { enabled: true, asLocalhost: false } }); // Get the network (channel) our contract is deployed to. const network = await gateway.getNetwork('mychannel'); // Get the contract from the network. const contract = network.getContract('fabcar'); // Evaluate the specified transaction. // queryCar transaction - requires 1 argument, ex: ('queryCar', 'CAR4') // queryAllCars transaction - requires no arguments, ex: ('queryAllCars') const result = await contract.evaluateTransaction('queryCar', req.params.car_index); console.log(`Transaction has been evaluated, result is: ${result.toString()}`); res.status(200).json({response: result.toString()}); } catch (error) { console.error(`Failed to evaluate transaction: ${error}`); res.status(500).json({error: error}); process.exit(1); } }); app.post('/api/addcar/', async function (req, res) { try { // Create a new file system based wallet for managing identities. const walletPath = path.join(process.cwd(), 'wallet'); const wallet = new FileSystemWallet(walletPath); console.log(`Wallet path: ${walletPath}`); // Check to see if we've already enrolled the user. const userExists = await wallet.exists('user1'); if (!userExists) { console.log('An identity for the user "user1" does not exist in the wallet'); console.log('Run the registerUser.js application before retrying'); return; } // Create a new gateway for connecting to our peer node. const gateway = new Gateway(); await gateway.connect(ccpPath, { wallet, identity: 'user1', discovery: { enabled: true, asLocalhost: false } }); // Get the network (channel) our contract is deployed to. const network = await gateway.getNetwork('mychannel'); // Get the contract from the network. const contract = network.getContract('fabcar'); // Submit the specified transaction. // createCar transaction - requires 5 argument, ex: ('createCar', 'CAR12', 'Honda', 'Accord', 'Black', 'Tom') // changeCarOwner transaction - requires 2 args , ex: ('changeCarOwner', 'CAR10', 'Dave') await contract.submitTransaction('createCar', req.body.carid, req.body.make, req.body.model, req.body.colour, req.body.owner); console.log('Transaction has been submitted'); res.send('Transaction has been submitted'); // Disconnect from the gateway. await gateway.disconnect(); } catch (error) { console.error(`Failed to submit transaction: ${error}`); process.exit(1); } }) app.put('/api/changeowner/:car_index', async function (req, res) { try { // Create a new file system based wallet for managing identities. const walletPath = path.join(process.cwd(), 'wallet'); const wallet = new FileSystemWallet(walletPath); console.log(`Wallet path: ${walletPath}`); // Check to see if we've already enrolled the user. const userExists = await wallet.exists('user1'); if (!userExists) { console.log('An identity for the user "user1" does not exist in the wallet'); console.log('Run the registerUser.js application before retrying'); return; } // Create a new gateway for connecting to our peer node. const gateway = new Gateway(); await gateway.connect(ccpPath, { wallet, identity: 'user1', discovery: { enabled: true, asLocalhost: false } }); // Get the network (channel) our contract is deployed to. const network = await gateway.getNetwork('mychannel'); // Get the contract from the network. const contract = network.getContract('fabcar'); // Submit the specified transaction. // createCar transaction - requires 5 argument, ex: ('createCar', 'CAR12', 'Honda', 'Accord', 'Black', 'Tom') // changeCarOwner transaction - requires 2 args , ex: ('changeCarOwner', 'CAR10', 'Dave') await contract.submitTransaction('changeCarOwner', req.params.car_index, req.body.owner); console.log('Transaction has been submitted'); res.send('Transaction has been submitted'); // Disconnect from the gateway. await gateway.disconnect(); } catch (error) { console.error(`Failed to submit transaction: ${error}`); process.exit(1); } }) app.listen(8080);
代码中对原来fabcar的query.js和invoke.js修改如下:
ccpPath修改为当前目录,因为我们要使用同一路径下的连接配置文件connection-org1.json
在gateway.connect调用中,修改选项discovery.asLocalhost为false
4、Rest API Server的连接配置文件
API服务依赖于连接配置文件来正确连接fabric网络。文件 connection-org1.json 可以直接从 fabric网络中获取:
{ "name": "first-network-org1", "version": "1.0.0", "client": { "organization": "Org1", "connection": { "timeout": { "peer": { "endorser": "300" } } } }, "organizations": { "Org1": { "mspid": "Org1MSP", "peers": [ "peer0.org1.example.com", "peer1.org1.example.com" ], "certificateAuthorities": [ "ca.org1.example.com" ] } }, "peers": { "peer0.org1.example.com": { "url": "grpcs://localhost:7051", "tlsCACerts": { "pem": "-----BEGIN CERTIFICATE-----\nMIICVjCCAf2gAwIBAgIQEB1sDT11gzTv0/N4cIGoEjAKBggqhkjOPQQDA jB2MQsw\nCQYDVQQGEwJVUzETMBEGA1UECBMKQ2FsaWZvcm5pYTEWMBQGA1UEBxMNU2FuIEZy\nYW5jaXNjbzEZMBcGA1UEChMQb3JnMS5leGF tcGxlLmNvbTEfMB0GA1UEAxMWdGxz\nY2Eub3JnMS5leGFtcGxlLmNvbTAeFw0xOTA5MDQwMjQzMDBaFw0yOTA5MDEwMjQz\nMDBaMHYxCzAJB gNVBAYTAlVTMRMwEQYDVQQIEwpDYWxpZm9ybmlhMRYwFAYDVQQH\nEw1TYW4gRnJhbmNpc2NvMRkwFwYDVQQKExBvcmcxLmV4YW1wbGUuY29tM R8wHQYD\nVQQDExZ0bHNjYS5vcmcxLmV4YW1wbGUuY29tMFkwEwYHKoZIzj0CAQYIKoZIzj0D\nAQcDQgAEoN0qd5hM2SDfvGzNjTCXuQqyk+X K4VISa16/y9iXBPpa0onyAXJuv7T0\noPf+mh4T7/g8uYtV2bwTpT2XFO3Q6KNtMGswDgYDVR0PAQH/BAQDAgGmMB0GA1Ud\nJQQWMBQGCCsGA QUFBwMCBggrBgEFBQcDATAPBgNVHRMBAf8EBTADAQH/MCkGA1Ud\nDgQiBCCalpyChmrLtpgOll6TVmlMOO/2iiyI2PadNPsIYx51mTAKBggqh kjOPQQD\nAgNHADBEAiBLNoAYWe9LvoxxBxl3sUM64kl7rx6dI3JU+dJG6FRxWgIgCu1ONEyp\nfux9lZWr6gcrIdsn/8fQuWiOIbAgq0HSr60 =\n-----END CERTIFICATE-----\n" }, "grpcOptions": { "ssl-target-name-override": "peer0.org1.example.com", "hostnameOverride": "peer0.org1.example.com" } }, "peer1.org1.example.com": { "url": "grpcs://localhost:8051", "tlsCACerts": { "pem": "-----BEGIN CERTIFICATE-----\nMIICVjCCAf2gAwIBAgIQEB1sDT11gzTv0/N4cIGoEjAKBggqhkjOPQQDA jB2MQsw\nCQYDVQQGEwJVUzETMBEGA1UECBMKQ2FsaWZvcm5pYTEWMBQGA1UEBxMNU2FuIEZy\nYW5jaXNjbzEZMBcGA1UEChMQb3JnMS5leGF tcGxlLmNvbTEfMB0GA1UEAxMWdGxz\nY2Eub3JnMS5leGFtcGxlLmNvbTAeFw0xOTA5MDQwMjQzMDBaFw0yOTA5MDEwMjQz\nMDBaMHYxCzAJB gNVBAYTAlVTMRMwEQYDVQQIEwpDYWxpZm9ybmlhMRYwFAYDVQQH\nEw1TYW4gRnJhbmNpc2NvMRkwFwYDVQQKExBvcmcxLmV4YW1wbGUuY29tM R8wHQYD\nVQQDExZ0bHNjYS5vcmcxLmV4YW1wbGUuY29tMFkwEwYHKoZIzj0CAQYIKoZIzj0D\nAQcDQgAEoN0qd5hM2SDfvGzNjTCXuQqyk+X K4VISa16/y9iXBPpa0onyAXJuv7T0\noPf+mh4T7/g8uYtV2bwTpT2XFO3Q6KNtMGswDgYDVR0PAQH/BAQDAgGmMB0GA1Ud\nJQQWMBQGCCsGA QUFBwMCBggrBgEFBQcDATAPBgNVHRMBAf8EBTADAQH/MCkGA1Ud\nDgQiBCCalpyChmrLtpgOll6TVmlMOO/2iiyI2PadNPsIYx51mTAKBggqh kjOPQQD\nAgNHADBEAiBLNoAYWe9LvoxxBxl3sUM64kl7rx6dI3JU+dJG6FRxWgIgCu1ONEyp\nfux9lZWr6gcrIdsn/8fQuWiOIbAgq0HSr60 =\n-----END CERTIFICATE-----\n" }, "grpcOptions": { "ssl-target-name-override": "peer1.org1.example.com", "hostnameOverride": "peer1.org1.example.com" } } }, "certificateAuthorities": { "ca.org1.example.com": { "url": "https://localhost:7054", "caName": "ca-org1", "tlsCACerts": { "pem": "-----BEGIN CERTIFICATE-----\nMIICUTCCAfegAwIBAgIQSiMHm4n9QvhD6wltAHkZPTAKBggqhkjOPQQDA jBzMQsw\nCQYDVQQGEwJVUzETMBEGA1UECBMKQ2FsaWZvcm5pYTEWMBQGA1UEBxMNU2FuIEZy\nYW5jaXNjbzEZMBcGA1UEChMQb3JnMS5leGF tcGxlLmNvbTEcMBoGA1UEAxMTY2Eu\nb3JnMS5leGFtcGxlLmNvbTAeFw0xOTA5MDQwMjQzMDBaFw0yOTA5MDEwMjQzMDBa\nMHMxCzAJBgNVB AYTAlVTMRMwEQYDVQQIEwpDYWxpZm9ybmlhMRYwFAYDVQQHEw1T\nYW4gRnJhbmNpc2NvMRkwFwYDVQQKExBvcmcxLmV4YW1wbGUuY29tMRwwG gYDVQQD\nExNjYS5vcmcxLmV4YW1wbGUuY29tMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE\nz93lOhLJG93uJQgnh93QcPPal5NQXQnAutF KYkun/eMHMe23wNPd0aJhnXdCjWF8\nMRHVAjtPn4NVCJYiTzSAnaNtMGswDgYDVR0PAQH/BAQDAgGmMB0GA1UdJQQWMBQG\nCCsGAQUFBwMCB ggrBgEFBQcDATAPBgNVHRMBAf8EBTADAQH/MCkGA1UdDgQiBCDK\naDhLwl3RBO6eKgHh5lHJovIyDJO3jTNb1ix1W86bFjAKBggqhkjOPQQDA gNIADBF\nAiEA8KTKkjQwb1TduTWWkmsLmKdxrlE6/H7CfsdeGE+onewCIHJ1S0nLhbWYv+G9\nTbAFlNCpqr0AQefaRT3ghdURrlbo\n----- END CERTIFICATE-----\n" }, "httpOptions": { "verify": false } } } }
当fabcar/startFabric.sh执行时,我们可以交叉检查证书的传播是否正确。 peer0.org1和 peer1.org1 的证书是org1的 TLS root CA 证书签名的。
注意所有的节点都以localhost引用,我们稍后会将其修改为Fabric Node的公开IP地址。
5、用户身份标识
我们已经在Fabric节点上生成了一个用户标识user1并保存在wallet目录中,我们可以看到有三个对应的文件:私钥、公钥和证书对象:
稍后我们会把这些文件拷贝到Rest API Server上。
6、安装Rest API Server节点
1、首先在Rest API Server节点上安装npm、node:
sudo apt-get update sudo apt install curl curl -sL https://deb.nodesource.com/setup_8.x | sudo bash - sudo apt install -y nodejs sudo apt-get install build-essentialnode -v npm -v
验证结果如下:
2、然后在Rest API Server上创建一个目录:
mkdir apiserver cd apiserver
3、接下来将下面的文件从Fabric节点拷贝到Rest API Server节点。我们 利用loccalhost在两个EC2实例间拷贝:
# localhost (update your own IP of the two servers) # temp is an empty directory cd temp scp -i ~/Downloads/aws.pem ubuntu@[Fabric-Node-IP]:/home/ubuntu/fabric-samples/first-network/connection-org1.json . scp -i ~/Downloads/aws.pem ubuntu@[Fabric-Node-IP]:/home/ubuntu/fabric-samples/fabcar/javascript/package.json . scp -r -i ~/Downloads/aws.pem ubuntu@[Fabric-Node-IP]:/home/ubuntu/fabric-samples/fabcar/javascript/wallet/user1/ . scp -r -i ~/Downloads/aws.pem * ubuntu@[API-Server-Node-IP]:/home/ubuntu/apiserver/
运行结果如下:
4、可以看到现在所有的文件都拷贝到Rest API Server了,为了保持一致,我们将user1/改名为wallet/user1/:
cd apiserver mkdir wallet mv user1 wallet/user1
运行结果如下:
5、现在在Rest API Server上创建上面的apiserver.js文件。
6、修改连接配置文件connection-org1.json 中的fabric节点的ip地址:
sed -i 's/localhost/[Fabric-Node-IP]/g' connection-org1.json
运行结果如下:
7、在/etc/hosts中增加条目以便可以正确解析fabric节点的IP:
127.0.0.1 localhost [Fabric-Node-IP] orderer.example.com [Fabric-Node-IP] peer0.org1.example.com [Fabric-Node-IP] peer1.org1.example.com [Fabric-Node-IP] peer0.org2.example.com [Fabric-Node-IP] peer1.org2.example.com
运行结果如下:
8、安装必要的依赖包:
npm install npm install express body-parser --save
9、万事俱备,启动Rest API Server:
node apiserver.js
7、访问API
我们的API服务在8080端口监听,在下面的示例中,我们使用curl来 演示如何访问。
1、查询所有车辆记录
curl http://[API-Server-Node-IP]:8080/api/queryallcars
运行结果如下:
2、添加新的车辆记录并查询
curl -d '{"carid":"CAR12","make":"Honda","model":"Accord","colour":"black","owner":"Tom"}' -H "Content-Type: application/json" -X POST http://[API-Server-Node-IP]:8080/api/addcar curl http://[API-Server-Node-IP]:8080/api/query/CAR12
运行结果如下:
3、修改车辆所有者并再次查询
curl http://[API-Server-Node-IP]:8080/api/query/CAR4 curl -d '{"owner":"KC"}' -H "Content-Type: application/json" -X PUT http://[API-Server-Node-IP]:8080/api/changeowner/CAR4 curl http://[API-Server-Node-IP]:8080/api/query/CAR4
运行结果如下:
我们也可以用postman得到同样的结果:
以上是“如何利用Hyperledger Fabric的SDK来开发REST API服务器”这篇文章的所有内容,感谢各位的阅读!相信大家都有了一定的了解,希望分享的内容对大家有所帮助,如果还想学习更多知识,欢迎关注创新互联行业资讯频道!
分享名称:如何利用HyperledgerFabric的SDK来开发RESTAPI服务器
文章URL:http://pwwzsj.com/article/jhceep.html