详细解析blance transfer示例的安装（install）和实例化（Instantiate）链码（chaincode）的过程。安装chaincode会根据本地的链码文件生成chaincode镜像，实例化chaincode则会启动该镜像，使链码在docker容器中运行。
安装chaincode
1.首先看app.js中的路由函数
app.post('/chaincodes', async function(req, res) {
var peers = req.body.peers; // 目标节点列表
var chaincodeName = req.body.chaincodeName; // chaincode名称
var chaincodePath = req.body.chaincodePath; // chaincode路径
var chaincodeVersion = req.body.chaincodeVersion; // chaincode版本
var chaincodeType = req.body.chaincodeType; // chaincode类型 Eg. golong
/*
省略了参数校验
*/
// 安装chaincode
let message = await install.installChaincode(peers, chaincodeName, chaincodePath, chaincodeVersion, chaincodeType, req.username, req.orgname)
res.send(message);
});2.再来看install-chaincode.js
var installChaincode = async function(peers, chaincodeName, chaincodePath,
chaincodeVersion, chaincodeType, username, org_name) {
logger.debug('
============ Install chaincode on organizations ============
');
helper.setupChaincodeDeploy();
let error_message = null;
try {
// 创建该组织对应的client，该client中包含用户信息_userContext
var client = await helper.getClientForOrg(org_name, username);
// admin transactionID
tx_id = client.newTransactionID(true);
// 打包请求参数
var request = {
targets: peers,
chaincodePath: chaincodePath,
chaincodeId: chaincodeName,
chaincodeVersion: chaincodeVersion,
chaincodeType: chaincodeType
};
// 调用SDK中的installChaincode()方法,根据request生成交易提案
// 然后通过sendPeersProposal()方法提交给所有背书节点，该方法获得提案响应的集合
// 最终返回 生成的交易提案 和 收集到的提案响应集合（内含背书签名）
// 之后将两者会作为交易的内容发送给orderer服务
let results = await client.installChaincode(request);
var proposalResponses = results[0]; // 背书响应集合
var proposal = results[1]; // 交易提案
// 检查提案响应是否均存在且合格
var all_good = true;
for (var i in proposalResponses) {
let one_good = false;
if (proposalResponses && proposalResponses[i].response &&
proposalResponses[i].response.status === 200) {
one_good = true;
logger.info('install proposal was good');
} else {
logger.error('install proposal was bad %j',proposalResponses.toJSON());
}
all_good = all_good & one_good;
}
if (all_good) {
logger.info('Successfully sent install Proposal and received ProposalResponse');
} else {
error_message = 'Failed to send install Proposal or receive valid response. Response null or status is not 200'
logger.error(error_message);
}
} 这一步完成后会生成chiancode镜像，内部包含chaincode源码go文件编译生成的可执行文件。
实例化chaincode
1.首先看app.js中的路由函数
app.post('/channels/:channelName/chaincodes', async function(req, res) {
var peers = req.body.peers;
var chaincodeName = req.body.chaincodeName;
var chaincodeVersion = req.body.chaincodeVersion;
var channelName = req.params.channelName;
var chaincodeType = req.body.chaincodeType;
var fcn = req.body.fcn;
var args = req.body.args;
// 实例化chaincode
let message = await instantiate.instantiateChaincode(peers, channelName, chaincodeName, chaincodeVersion, chaincodeType, fcn, args, req.username, req.orgname);
res.send(message);
});2.再来看instantiate-chaincode.js
var instantiateChaincode = async function(peers, channelName, chaincodeName, chaincodeVersion, functionName, chaincodeType, args, username, org_name) {
var error_message = null;
try {
// 创建该组织名对应的client，并为其分配了用户对象
var client = await helper.getClientForOrg(org_name, username);
// 获取channel对象
var channel = client.getChannel(channelName);
// 获取基于msp管理员的TransactionID，这表示实例化链码的交易提案
// 需要用到组织管理员的身份进行签名
var tx_id = client.newTransactionID(true);
// 这个transaction ID 会用来登记（register）事件监听
var deployId = tx_id.getTransactionID();
// 构造请求结构
var request = {
targets : peers,
chaincodeId: chaincodeName,
chaincodeType: chaincodeType,
chaincodeVersion: chaincodeVersion,
args: args,
txId: tx_id
};
if (functionName)
request.fcn = functionName;
let results = await channel.sendInstantiateProposal(request, 60000);
// 返回的 交易提案 和 提案相应
var proposalResponses = results[0];
var proposal = results[1];
// 检查提案响应中是否包含正确的背书签名
var all_good = true;
for (var i in proposalResponses) {
let one_good = false;
if (proposalResponses && proposalResponses[i].response &&
proposalResponses[i].response.status === 200) {
one_good = true;
logger.info('instantiate proposal was good');
} else {
logger.error('instantiate proposal was bad');
}
all_good = all_good & one_good;
}
// 等待channel的eventHub通知我们交易被peer节点提交
var promises = [];
let event_hubs = channel.getChannelEventHubsForOrg();
#event_hubs.forEach((eh) => {
#let instantiateEventPromise = new Promise((resolve, reject) => {
#let event_timeout = setTimeout(() => {
let message = 'REQUEST_TIMEOUT:' + eh.getPeerAddr();
logger.error(message);
eh.disconnect();
}, 60000);
// 注册交易事件监听
#eh.registerTxEvent(deployId, (tx, code, block_num) => {
clearTimeout(event_timeout);
}, (err) => {
clearTimeout(event_timeout);
logger.error(err);
reject(err);
},
{unregister: true, disconnect: true}
);
eh.connect();
});
promises.push(instantiateEventPromise);
});
// 构造交易请求，包含交易id、交易提案、提案响应
var orderer_request = {
txId: tx_id, // 组织admin进行签名的交易id
proposalResponses: proposalResponses,
proposal: proposal
};
// 发送交易请求到Orderer节点，内部通过调用orderer.sendBroadcast(envelope)实现
var sendPromise = channel.sendTransaction(orderer_request);
} else {
error_message = util.format('Failed to send Proposal and receive all good ProposalResponse');
logger.debug(error_message);
}
} catch (error) {
logger.error('Failed to send instantiate due to error: ' + error.stack ? error.stack : error);
error_message = error.toString();
}
};测试
安装
chaincodecurl -s -X POST http://localhost:4000/chaincodes -H "authorization: Bearer <Token>" -H "content-type: application/json" -d '{ "peers": ["peer0.org1.example.com","peer1.org1.example.com"], "chaincodeName":"mycc", "chaincodePath":"github.com/example_cc/go", "chaincodeType": "golang", "chaincodeVersion":"v0" }'结果：
{"success":true,"message":"Successfully install chaincode"}实例化
chaincodecurl -s -X POST http://localhost:4000/channels/mychannel/chaincodes -H "authorization: Bearer <token>" -H "content-type: application/json" -d '{ "peers": ["peer0.org1.example.com","peer1.org1.example.com"], "chaincodeName":"mycc", "chaincodeVersion":"v0", "chaincodeType": "golang", "args":["a","100","b","200"] }'结果：
{"success":true,"message":"Successfully instantiate chaingcode in organization Org1 to the channel 'mychannel'"}