电脑基础 · 2023年3月8日

部署智能合约到公链

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目录

1. 连接公链

1.1设置钱包

1.2 连接以太坊节点

1.3 更新项目设置

1.4 访问以太坊节点

2. 部署智能合约到公链

2.1获取测试以太币

2.2 部署智能合约

2.3 验证部署

3. truffle脚本


部署智能合约到公链

1. 连接公链

以太坊公链除了主网,还有多个测试网络。主网(Mainnet)是正式的以太坊网络,里面的以太币是真正有价值的,测试网络中的以太币没有价值,只用于测试。

我们最终目标是连接到主网,但先连接到测试网络Kovan,虽然本地区块链网络(Ganache)也能测试,但与公链还是有区别的。

连接到公链的步骤如下:

  1. 设置钱包来管理公链帐户
  2. 连接到以太坊节点
  3. 更新项目设置
  4. 访问以太坊节点

1.1设置钱包

首先需要设置一个钱包,来管理我们的公链帐户。

简单起见,可以借用Ganache本地区块链钱包,由于区块链的工作原理,这个钱包在公共区块链和本地区块链上都是有效的。

打开Ganache,主界面上可以看到一个名为“MNEMONIC”的部分:

部署智能合约到公链

 这是一个种子短语,用于构建由Ganache管理的钱包。我们可以使用这个种子短语加密重建钱包,来连接到公链。

复制这个值,保存到一个秘密文件,MNEMONIC是一个秘密值,需要保密。在项目根目录中创建一个.env文件,保存MNEMONIC值,如下所示:

MNEMONIC="你的mnemonic"

1.2 连接以太坊节点

现在已经创建了钱包,下一步需要访问Ethereum节点,以便连接到公共区块链网络。

有几种方法可以做到这一点,可以使用Geth或Parity运行自己的Ethereum节点。但这需要从区块链下载大量数据并保持同步,很麻烦。

比较方便的方法是,使用Infura访问Ethereum节点。Infura是一个免费提供Ethereum节点的服务。

在Infura上注册账号,创建项目,在项目详情页上可以查看API KEY:

部署智能合约到公链

 使用API KEY,就可以访问以太坊网络节点。

.env文件中添加Infura api key的配置:

INFURA_API_KEY="https://kovan.infura.io/v3/543526cd4d3846acbc3826484e934564"
MNEMONIC="你的mnemonic"

1.3 更新项目设置

接下来使用MNEMONICINFURA_API_KEY,更新项目的网络配置,以便连接到公共区块链网络。

修改truffle-config.js文件:

// 导入dotenv库创用于读取`.env`文件中的设置
require('dotenv').config();
// 导入truffle-hdwallet-provider库重建钱包
const HDWalletProvider = require('truffle-hdwallet-provider');
module.exports = {
  networks: {
    development: {
     host: "127.0.0.1",     // Localhost (default: none)
     port: 7545,            // Standard Ethereum port (default: none)
     network_id: "*",       // Any network (default: none)
    },
    // Useful for deploying to a public network.
    // NB: It's important to wrap the provider as a function.
    kovan: {
      provider: () => new HDWalletProvider(
        process.env.MNEMONIC,
        process.env.INFURA_API_KEY
      ),
      gas: 5000000,
      gasPrice: 25000000000,
      network_id: 42
    },
  },
  solc: {
    optimizer: {
      enabled: true,
      runs: 200
    }
  }
}

可以看到,我们使用了.env配置文件中的MNEMONICINFURA_API_KEY配置了kovan网络。

由于用到了dotenv与truffle-hdwallet-provider这2个库,我们需要先安装:

切换到项目目录,执行以下命令

npm install dotenv --save-dev
npm install truffle-hdwallet-provider --save-dev

注意 安装truffle-hdwallet-provider时,如果出现node-gyp相关的错误,可参考这里解决。

1.4 访问以太坊节点

使用truffle console连接到公共区块链网络:

$ truffle console --network kovan

要验证连接,可以从区块链中读取一些数据,获取一些关于最新区块的信息,在控制台上执行:

web3.eth.getBlock('latest').then(console.log)

输出:

{ author: '0x03801efb0efe2a25ede5dd3a003ae880c0292e4d',
  difficulty: '340282366920938463463374607431768211454',
  extraData:
   '0xde830206028f5061726974792d457468657265756d86312e33362e30826c69',
  gasLimit: '0x7a1200',
  gasUsed: '0x17d23',
  hash:
   '0xc7390c4f492c8c1da60608135fc9e05930123b645b39f221cba33d8b3c577b2a',
  logsBloom:
   '0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000080000000000000000000100000008000000000000000000080000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000400800000000000010000000000000080000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000009000000008000000',
  receiptsRoot:
   '0x3d05bb2ed4fcc90234eea6d840e7d0e3ce7f598a15e5314536b17bcd11c78b5b',
  sealFields:
   [ '0x84175e8801',
     '0xb84155a8cdb108dccec1d314124058fa6f22e7400ee200db0a94b7b165e4c3454c1818cc05f815cb7ce48f7a88b8401515740311a3566d9cf079428d506a6daca50101' ],
  sha3Uncles:
   '0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347',
  signature:
   '55a8cdb108dccec1d314124058fa6f22e7400ee200db0a94b7b165e4c3454c1818cc05f815cb7ce48f7a88b8401515740311a3566d9cf079428d506a6daca50101',
  size: 877,
  stateRoot:
   '0x03af5adce52a81ce5d332cddb9955e344214bff00859b78868116e1e839efdf7',
  step: '392071169',
  timestamp: 1568284676,
  totalDifficulty: '4524524338444961608702071789512829094373049115',
  transactions:
   [ '0xded7fed0842fd65ec808bc3652ec4175bc190acc11345c49c44b1fb5d954610f',
     '0x7e9112a46fa3c07aad813ea86355b15eebb44023c040d198ee7d15d379bbc2be' ],
  transactionsRoot:
   '0x0dd10d90686dda2684bd0ba70d1c9e1d9a5302c30ca75eb2c5b07a7b6e4498b9',
  uncles: [] }

可以看到,已经成功连接到了公链。

2. 部署智能合约到公链

现在,我们将智能合约部署到公链。步骤如下:

  1. 部署需要消耗Gas,获取测试以太币用于部署
  2. 部署智能合约
  3. 验证部署

2.1获取测试以太币

部署需要消耗Gas,Gas需要支付以太币,我们部署到的是公链测试网Kovan,网络中的以太币没有市场价值。

可以从Kovan faucet Gitter聊天室获取测试用的伪以太币。只需把钱包地址发送出去,约5分钟内,有人会给你发测试用的伪以太币。

打开Ganache并复制列表中第一个帐户的地址(钱包地址),类似下面所示:

0x29920e756f41F8e691aE0b12D417C19204371E91

发送到聊天室内,稍等片刻,你的账号将收到一笔以太币。

2.2 部署智能合约

现在帐户里已经有了资金,可以进行部署了。

执行部署命令:

truffle migrate --network kovan

一旦部署完成,应该会看到部署成功的消息。

部署命令执行详情:

G:\qikegu\ethereum\mydapp>truffle migrate --network kovan
Compiling your contracts...
===========================
> Everything is up to date, there is nothing to compile.
Migrations dry-run (simulation)
===============================
> Network name:    'kovan-fork'
> Network id:      42
> Block gas limit: 0x7a1200
...
Starting migrations...
======================
> Network name:    'kovan'
> Network id:      42
> Block gas limit: 0x7a1200
1_initial_migration.js
======================
   Deploying 'Migrations'
   ----------------------
   > transaction hash:    0x7e30b5c716afed45888a9dd2d6af7e6f52a9fade0346e8ad7d0c268de508a26a
   > Blocks: 2            Seconds: 9
   > contract address:    0x168A7247B58786edd259502948f5Bf9449C863AD
   > block number:        13447029
   > block timestamp:     1568294312
   > account:             0x29920e756f41F8e691aE0b12D417C19204371E91
   > balance:             2.993465175
   > gas used:            261393
   > gas price:           25 gwei
   > value sent:          0 ETH
   > total cost:          0.006534825 ETH
   > Saving migration to chain.
   > Saving artifacts
   -------------------------------------
   > Total cost:         0.006534825 ETH
2_deploy_contracts.js
=====================
   Deploying 'MyContract'
   ----------------------
   > transaction hash:    0xc1f7ec8fee1a23e3d08d0c9e9d6e15fef24feb8ba163e0071dccb1bb90cc0eca
   > Blocks: 0            Seconds: 0
   > contract address:    0x4D3CFaF8457CEA76c0409f989f9870115B4d2d82
   > block number:        13447036
   > block timestamp:     1568294340
   > account:             0x29920e756f41F8e691aE0b12D417C19204371E91
   > balance:             2.9850534
   > gas used:            294448
   > gas price:           25 gwei
   > value sent:          0 ETH
   > total cost:          0.0073612 ETH
   > Saving migration to chain.
   > Saving artifacts
   -------------------------------------
   > Total cost:           0.0073612 ETH
Summary
=======
> Total deployments:   2
> Final cost:          0.013896025 ETH
Summary
=======
> Total deployments:   2
> Final cost:          0.013896025 ETH

2.3 验证部署

现在打开truffle控制台,与kovan测试网络上的智能合约进行交互:

$ truffle console --network kovan

在控制台中执行:

truffle(kovan)> MyContract.deployed().then((c) => { contract = c })

然后:

truffle(kovan)> contract.get()
'myValue'
truffle(kovan)> contract.set("hello world")
{ tx:
   '0x7bf63444f3a7bd70e981a7bd49228b1cf1a8c3754daf64c4c7765b8eee46bf37',
  receipt:
   { blockHash:
      '0xe03d0f43d85f4e41c18a90aa563ebda08899c6b9c38d0cd7779937046e2aed0c',
     blockNumber: 13447763,
     contractAddress: null,
     cumulativeGasUsed: 33629,
     from: '0x29920e756f41f8e691ae0b12d417c19204371e91',
     gasUsed: 33629,
     logs: [],
     logsBloom:
      '0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
     root: null,
     status: true,
     to: '0x4d3cfaf8457cea76c0409f989f9870115b4d2d82',
     transactionHash:
      '0x7bf63444f3a7bd70e981a7bd49228b1cf1a8c3754daf64c4c7765b8eee46bf37',
     transactionIndex: 0,
     rawLogs: [] },
  logs: [] }
truffle(kovan)> contract.get()
'hello world'

可以看到智能合约已经成功部署。

3. truffle脚本

Truffle包含一个脚本运行器,可对以太坊网络执行自定义脚本。

让我们创建一个脚本并执行。

在项目根目录下,创建script.js文件,内容如下:

module.exports = function(callback) {
  web3.eth.getBlock('latest').then(console.log)
}

该脚本将从Kovan测试网络获取最新区块的信息。

执行脚本:

truffle exec script.js --network kovan

输出:

{ author: '0x596e8221a30bfe6e7eff67fee664a01c73ba3c56',
  difficulty: '340282366920938463463374607431768211454',
  extraData:
   '0xde830205058f5061726974792d457468657265756d86312e33362e30826c69',
  gasLimit: '0x7a1200',
  gasUsed: '0x5e61',
  hash:
   '0x225a1e0b13fd20396af60d049ce9bb94c2f3f7df06c7db260880b62c91997004',
  logsBloom:
   '0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
  miner: '0x596e8221A30bFe6e7eFF67Fee664A01C73BA3C56',
  number: 13448162,
  parentHash:
   '0x28d00fd7b66771130ed98de5073c7797ee293e7bee4b546793a4b79171555066',
  receiptsRoot:
   '0x44617b5733ee59bde159af08ffd6edae36e0964f1724c333f3d1bef0808dee15',
  sealFields:
   [ '0x84175e95d7',
     '0xb8412ed900e67f4a72925fb3b495efb3f547411f40d26e972cc0e8b2cf26e40cf84a545e0328199d4880b79c62670129a7db12ac58234bee0866c6376b46ab99e8a200' ],
  sha3Uncles:
   '0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347',
  signature:
   '2ed900e67f4a72925fb3b495efb3f547411f40d26e972cc0e8b2cf26e40cf84a545e0328199d4880b79c62670129a7db12ac58234bee0866c6376b46ab99e8a200',
  size: 797,
  stateRoot:
   '0xe1bbaacfb950361bec70f4ad53a2605e1ac1d2ff0bfd913fe063dc6c5f3252a0',
  step: '392074711',
  timestamp: 1568298844,
  totalDifficulty: '4525729278306228651801195598997744985609807728',
  transactions:
   [ '0xf1ae41eac6b32419bc62a6cde9cab4b4ca244899a3d49b4a2461bcf94f504176' ],
  transactionsRoot:
   '0xf08c8097ea946f84ce9594ce73648fc0f9f683adef105a5db00c5f1f15e61c2c',
  uncles: [] }

下面的代码智能合约MyContract中,读取value值,将script.js脚本文件中的代码替换为:

const MyContract = artifacts.require("./MyContract.sol");
module.exports = async function(callback) {
  const contract = await MyContract.deployed()
  const value = await contract.get()
  console.log("Value:", value)
}

执行脚本:

truffle exec script.js --network kovan

输出:

Value: hello world

脚本运行器是一个非常有用的功能。