如何构建无服务器智能合约自动化项目

= lastTriggeredAt + 1 hour);"],[20,"\n","24:\"Y7Ln\"|36:177"],[20," ..."],[20,"\n","24:\"Eqxc\"|36:177"],[20,"}"],[20,"\n","24:\"pKDU\"|36:177"],[20,"\t以上“require()”语句可确保两次执行至少间隔一小时。但是，仍需要在开始时人为触发智能合约，然后代码才会正常运行。"],[20,"\n","24:\"2Fgq\"|7:3"],[20,"来谈一谈“自动e执行”","0:\"%23ed7d31\""],[20,"\n","24:\"0Qrh\"|7:3"],[20,"\t从技术层面上来看，有一些操作是可以使用函数修改器来自动执行的。比如说Compound Governance的COMP分配。一旦地址获得了0.001COMP，之后所有的Compound交易（例如提供资产，或转移cToken）都会自动将COMP转到其钱包中。"],[20,"\n","24:\"gcwW\"|7:3"],[20,"\t我们可以在函数修改器中实现上述逻辑，将修改器放在函数前，并在调用函数时自动执行逻辑。由调用方来支付相关的附加费用。"],[20,"\n","24:\"SdCR\"|7:3"],[20,"\t然而，并不是所有的智能合约系统都可以采用这种方法。由于这些修改器只能在特定条件下运行，因此可能会导致意料之外的gas费用。同时，还可能会向用户随机收取额外的gas费用，以实现合约“平衡性”。"],[20,"\n","24:\"UE1L\"|7:3"],[20,"\t并且，代码的运行仍然需要通过人为调用智能合约才能实现。"],[20,"\n","24:\"84Wo\"|7:3"],[20,"智能合约自动化的常见用例","0:\"%23ed7d31\""],[20,"\n","24:\"ylI9\"|7:3"],[20,"\tDeFi协议依赖于某种链下智能合约自动化。MakerDAO依赖第三方来监控债务头寸的抵押担保比率，并清算担保不足的头寸。其他的DeFi协议也都有类似的需求。"],[20,"\n","24:\"kzHE\"|7:3"],[20,"\t在链下智能合约自动化方面，有两个常见用例："],[20,"\n","24:\"4E62\"|7:3"],[20,"自动触发器（Automated Triggers）：在特定情况下执行合约。","27:\"12\"|8:1"],[20,"\n","24:\"BRHr\"|27:\"12\"|bullet-id:\"IFIv\"|bullet:\"circle\""],[20,"状态和事件监控（State and Event Monitoring）：了解合约在何时出现特定状态。","27:\"12\"|8:1"],[20,"\n","24:\"WLyc\"|27:\"12\"|bullet-id:\"IFIv\"|bullet:\"circle\""],[20,"1. 自动触发器","27:\"12\""],[20,"\n","24:\"voxY\""],[20,"\t我们经常需要定期、或在特定条件下执行合约，例如："],[20,"\n","24:\"9BtC\"|7:3"],[20,"周期性地恢复平衡池","27:\"12\""],[20,"\n","24:\"rocz\"|27:\"12\"|bullet-id:\"i378\"|bullet:\"circle\""],[20,"结束DAO/治理过程中的投票","27:\"12\""],[20,"\n","24:\"DCLG\"|27:\"12\"|bullet-id:\"i378\"|bullet:\"circle\""],[20,"按比例支付安全代币股息","27:\"12\""],[20,"\n","24:\"q1Ie\"|27:\"12\"|bullet-id:\"i378\"|bullet:\"circle\""],[20,"2. 状态和事件监控"],[20,"\n","24:\"QSw5\"|7:3"],[20,"\t有时我们需要了解合约是否满足了某些条件，例如："],[20,"\n","24:\"lBSi\"|7:3"],[20,"了解智能合约的价值是否发生了变化","27:\"12\""],[20,"\n","24:\"4D7H\"|27:\"12\"|bullet-id:\"6BqR\"|bullet:\"circle\""],[20,"获取所有准入限制更改的通知","27:\"12\""],[20,"\n","24:\"iyGl\"|27:\"12\"|bullet-id:\"6BqR\"|bullet:\"circle\""],[20,"了解何时发出特定的智能合约事件","27:\"12\""],[20,"\n","24:\"HPdh\"|27:\"12\"|bullet-id:\"6BqR\"|bullet:\"circle\""],[20,"解决方案：无服务器函数？","0:\"%23ed7d31\""],[20,"\n","24:\"ymMx\"|7:3"],[20,"\t实际上，无服务器功能刚好适用于上面提到的这几个用例。有了无服务器化，我们便无需在部署代码之前预配任何东西，并且之后也不需要费心管理，极大地简化了问题的解决方案。"],[20,"\n","24:\"dmzk\"|7:3"],[20,"快速入门：借助Serverless Framework来实现无服务器化","0:\"%23ed7d31\""],[20,"\n","24:\"CkoA\"|7:3"],[20,"\t无服务器架构（Serverless Framework）为我们提供了开发、部署、监控和保护无服务器应用程序所需的一切内容。让我们一起来看看如何能够以最简单的方式完成开发吧。"],[20,"\n","24:\"wFzK\"|7:3"],[20,"> npm install -g serverless"],[20,"\n","24:\"5pRP\"|36:177"],[20,"> serverless -v"],[20,"\n","24:\"xNab\"|36:177"],[20,"x.x.x"],[20,"\n","24:\"tuIh\"|36:177"],[20,"\t首先，我们来快速了解一下Serverless Framework的运作方式。"],[20,"\n","24:\"4lZj\"|7:3"],[20,"0. serverless.yml","8:1"],[20,"\n","24:\"Fszg\"|7:3"],[20,"\t所有Serverless服务中的Lambda函数和事件都可以在名为serverless.yml的配置文件中找到。该文件对服务（包含Functions和Events）进行了定义。"],[20,"\n","24:\"yVl2\"|7:3"],[20,"service: serverless-ethers"],[20,"\n","24:\"h3IV\"|36:177"],[20,"provider:"],[20,"\n","24:\"vX6G\"|36:177"],[20," name: aws"],[20,"\n","24:\"BYPY\"|36:177"],[20," runtime: nodejs12.x"],[20,"\n","24:\"KQv7\"|36:177"],[20," environment:"],[20,"\n","24:\"HTbp\"|36:177"],[20," CHAIN_ID: 3"],[20,"\n","24:\"tTpR\"|36:177"],[20," DEFAULT_GAS_PRICE: 60000000000"],[20,"\n","24:\"Tti9\"|36:177"],[20,"\n","24:\"P7rJ\"|36:177"],[20,"functions:"],[20,"\n","24:\"70LP\"|36:177"],[20," myFunc:"],[20,"\n","24:\"ZhNL\"|36:177"],[20," handler: functions/myFunc.handler"],[20,"\n","24:\"x4KH\"|36:177"],[20," events:"],[20,"\n","24:\"G2yQ\"|36:177"],[20," - schedule: rate(2 hours)"],[20,"\n","24:\"SMlj\"|36:177"],[20,"\t我们可以在"],[20,"function","1:\"%23d9d9d9\""],[20,"属性下，对无服务器函数进行定义。在上面的例子中："],[20,"\n","24:\"VexS\"|7:3"],[20,"我们有名为","27:\"12\""],[20,"myFunc","1:\"%23d9d9d9\"|27:\"12\""],[20,"的Function","27:\"12\""],[20,"\n","24:\"YhJ3\"|27:\"12\"|bullet-id:\"zkiM\"|bullet:\"circle\""],[20,"handler","1:\"%23d9d9d9\"|27:\"12\""],[20,"属性指向包含你想在函数中运行的代码的文件和模块","27:\"12\""],[20,"\n","24:\"fA9U\"|27:\"12\"|bullet-id:\"zkiM\"|bullet:\"circle\""],[20,"events","1:\"%23d9d9d9\"|27:\"12\""],[20,"属性为要执行的函数指定Event触发器","27:\"12\""],[20,"\n","24:\"JzbL\"|27:\"12\"|bullet-id:\"zkiM\"|bullet:\"circle\""],[20,"\t一个服务中可以包含多个函数。"],[20,"\n","24:\"ZJuS\"|7:3"],[20,"1.","8:1"],[20," ","27:\"9\"|31:12|8:1"],[20,"Functions","8:1"],[20," "],[20,"\n","24:\"jXu3\"|7:3"],[20,"\tFunction是AWS Lambda函数，是一个类似于微服务的独立部署单元。作为一段部署在云中的代码，通常被用于执行单个作业。"],[20,"\n","24:\"Uiga\"|7:3"],[20,"// functions/myFunc.js"],[20,"\n","24:\"6gxf\"|36:177"],[20,"exports.handler = async function(event, context) {"],[20,"\n","24:\"FHen\"|36:177"],[20," // Do anything"],[20,"\n","24:\"RfVh\"|36:177"],[20,"};"],[20,"\n","24:\"Kd4L\"|36:177"],[20,"\tFunctions只是普通的JS函数，可以将事件对象作为有效负载。"],[20,"\n","24:\"yBt8\"|7:3"],[20,"2. Events","8:1"],[20,"\n","24:\"wEKC\""],[20,"\tEvents是触发函数运行的事件，隶属于每个Function，可以在"],[20,"serverless.yml","1:\"%23d9d9d9\""],[20,"中的事件属性中找到。"],[20,"\n","24:\"zwtB\"|7:3"],[20,"\t我们可以使用Scheduled Events触发器来定期自动执行函数。例如，我们指定每2小时运行一次myFunc函数："],[20,"\n","24:\"NIt6\"|7:3"],[20,"# serverless.yml"],[20,"\n","24:\"yeei\"|36:177"],[20,"\n","24:\"J49m\"|36:177"],[20,"functions:"],[20,"\n","24:\"1H9B\"|36:177"],[20," myFunc:"],[20,"\n","24:\"UOXm\"|36:177"],[20," handler: functions/myFunc.handler"],[20,"\n","24:\"CH2K\"|36:177"],[20," events:"],[20,"\n","24:\"6WuV\"|36:177"],[20," - schedule: rate(2 hours)"],[20,"\n","24:\"PvRI\"|36:177"],[20,"\t我们还可以借助cron schedule expression来指定安排计划"],[20,"\n","24:\"cAJX\"|7:3"],[20,"# serverless.yml"],[20,"\n","24:\"Pxmm\"|36:177"],[20,"\n","24:\"XyAV\"|36:177"],[20,"events:"],[20,"\n","24:\"S7Td\"|36:177"],[20," - schedule: cron(0 12 * * ? *) # 12PM UTC"],[20,"\n","24:\"HbwP\"|36:177"],[20,"\t"],[20,"如果你使用的是AWS的话，事件即为AWS中可以出发AWS Lambda函数的任意事件，比如：","0:\"%233c3c3b\""],[20,"\n","24:\"KG8P\"|7:3"],[20,"AWS API Gateway HTTP端点请求（例如，REST API）","27:\"12\""],[20,"\n","24:\"ho8L\"|27:\"12\"|bullet-id:\"6xWq\"|bullet:\"circle\""],[20,"AWS S3存储桶上传（例如，图像）","27:\"12\""],[20,"\n","24:\"Rsbw\"|27:\"12\"|bullet-id:\"6xWq\"|bullet:\"circle\""],[20,"CloudWatch计时器（例如，每5分钟运行一次）","27:\"12\""],[20,"\n","24:\"QgLs\"|27:\"12\"|bullet-id:\"6xWq\"|bullet:\"circle\""],[20,"AWS SNS主题（例如，信息）","27:\"12\""],[20,"\n","24:\"vKv9\"|27:\"12\"|bullet-id:\"6xWq\"|bullet:\"circle\""],[20,"等等……","27:\"12\""],[20,"\n","24:\"KUSR\"|27:\"12\"|bullet-id:\"6xWq\"|bullet:\"circle\""],[20,"\t就目前而言，知道这些就够了。如果还想了解更多关于Serverless framework的内容的话，可以看一下这个文件（"],[20,"https://www.serverless.com/framework/docs/?ref=hackernoon.com","16:\"https%3A%2F%2Fwww.serverless.com%2Fframework%2Fdocs%2F%3Fref%3Dhackernoon.com\""],[20,"）"],[20,"\n","24:\"IWS8\"|7:3"],[20,"\t在了解了Serverless Framework的基础知识后，我们来看一看"],[20,"serverless-ethers","1:\"%23d9d9d9\""],[20,"服务吧。"],[20,"\n","24:\"dVqI\"|7:3"],[20,"serverless-ethers是什么","0:\"%23ed7d31\""],[20,"\n","24:\"nKbm\"|7:3"],[20,"\t"],[20,"serverless-ethers","1:\"%23d9d9d9\""],[20,"是一个全功能Serverless服务，部署后即可直接使用。"],[20,"\n","24:\"AFON\"|7:3"],[20,"git clone [email protected]:yosriady/serverless-ethers.git"],[20,"\n","24:\"z9Oa\"|36:177"],[20,"cd serverless-ethers"],[20,"\n","24:\"azhd\"|36:177"],[20,"nvm use"],[20,"\n","24:\"Ielg\"|36:177"],[20,"npm install"],[20,"\n","24:\"R4Wt\"|36:177"],[20,"\t我们可以将此项目作为构建自定义智能合约自动化的基础。其预先配置的是AWS，但修改后也适用于其他云提供商（如GCP、Azure等）。"],[20,"\n","24:\"35qT\"|7:3"],[20,"\t"],[20,"serverless-ethers","1:\"%23d9d9d9\""],[20,"项目的结构如下："],[20,"\n","24:\"OgTX\"|7:3"],[20,"├── contracts/"],[20,"\n","24:\"OITE\"|36:177"],[20,"│ ├── abis/"],[20,"\n","24:\"XGcf\"|36:177"],[20,"│ ├── abis.js"],[20,"\n","24:\"Md6M\"|36:177"],[20,"│ └── addresses.js"],[20,"\n","24:\"GNCQ\"|36:177"],[20,"├── functions/"],[20,"\n","24:\"At8I\"|36:177"],[20,"│ └── exec.js"],[20,"\n","24:\"L8Fs\"|36:177"],[20,"└── serverless.yml"],[20,"\n","24:\"4z7D\"|36:177"],[20,"contracts/","1:\"%23d9d9d9\"|27:\"12\""],[20,"包含智能合约ABI和地址。","27:\"12\""],[20,"\n","24:\"4tGl\"|27:\"12\"|bullet-id:\"8NAu\"|bullet:\"circle\""],[20,"functions/","1:\"%23d9d9d9\"|27:\"12\""],[20,"包含实现业务逻辑的JS函数。","27:\"12\""],[20,"\n","24:\"MhNX\"|27:\"12\"|bullet-id:\"8NAu\"|bullet:\"circle\""],[20,"serverless.yml","1:\"%23d9d9d9\"|27:\"12\""],[20,"描述服务配置。","27:\"12\""],[20,"\n","24:\"bBLp\"|27:\"12\"|bullet-id:\"8NAu\"|bullet:\"circle\""],[20,"\t接下来，我们将深入了解一下各个部分。"],[20,"\n","24:\"rZcI\"|7:3"],[20,"合约样本示例","0:\"%23ed7d31\""],[20,"\n","24:\"hIq4\"|7:3"],[20,"\t为了进行测试，我编写并部署了一个智能合约示例："],[20,"\n","24:\"crAe\"|7:3"],[20,"// SPDX-License-Identifier: GPL-3.0"],[20,"\n","24:\"3Dqz\"|36:177"],[20,"pragma solidity ^0.6.10;"],[20,"\n","24:\"3aVT\"|36:177"],[20,"\n","24:\"lu48\"|36:177"],[20,"contract DummyStorage {"],[20,"\n","24:\"NmsT\"|36:177"],[20," event Write(address indexed source, uint256 value);"],[20,"\n","24:\"o9F4\"|36:177"],[20,"\n","24:\"DsWP\"|36:177"],[20," uint internal _currentValue;"],[20,"\n","24:\"C1AR\"|36:177"],[20,"\n","24:\"7FlN\"|36:177"],[20," function get() public view returns (uint) {"],[20,"\n","24:\"aIgA\"|36:177"],[20," return _currentValue;"],[20,"\n","24:\"y1EZ\"|36:177"],[20," }"],[20,"\n","24:\"LlaB\"|36:177"],[20,"\n","24:\"63K3\"|36:177"],[20," function put(uint value) public {"],[20,"\n","24:\"eMtM\"|36:177"],[20," emit Write(msg.sender, value);"],[20,"\n","24:\"Bffc\"|36:177"],[20," _currentValue = value;"],[20,"\n","24:\"Eyqo\"|36:177"],[20," }"],[20,"\n","24:\"D2So\"|36:177"],[20,"}"],[20,"\n","24:\"e0Zd\"|36:177"],[20,"\t该"],[20,"DummyStorage","1:\"%23d9d9d9\""],[20,"智能合约具有以下功能："],[20,"\n","24:\"0E5G\"|7:3"],[20,"get","1:\"%23d9d9d9\"|27:\"12\""],[20,"是一个能反馈合约当前值的只读函数。","27:\"12\""],[20,"\n","24:\"oXQz\"|27:\"12\"|bullet-id:\"btx3\"|bullet:\"circle\""],[20,"put","1:\"%23d9d9d9\"|27:\"12\""],[20,"是一个用于更新合约当前值的写入函数。","27:\"12\""],[20,"\n","24:\"PiqO\"|27:\"12\"|bullet-id:\"btx3\"|bullet:\"circle\""],[20,"\t该示例合约已经过验证并在Ropsten上运行。大家可以用它来测试自己的函数！"],[20,"\n","24:\"6vSy\"|7:3"],[20,"1. 智能合约ABIs","8:1"],[20,"\n","24:\"lfyS\"|7:3"],[20,"\t合约目录中包含与函数交互的合约ABIs。在示例项目中，它包含DummyStorage合约的ABI。"],[20,"\n","24:\"riWS\"|7:3"],[20,"├── contracts/"],[20,"\n","24:\"k1ZQ\"|36:177"],[20,"│ ├── abis/"],[20,"\n","24:\"8hQs\"|36:177"],[20,"│ │ └── DummyStorage.json"],[20,"\n","24:\"8nBq\"|36:177"],[20,"│ ├── abis.js"],[20,"\n","24:\"swUN\"|36:177"],[20,"│ └── addresses.js"],[20,"\n","24:\"HCGl\"|36:177"],[20,"\t我们可以将ABI看作是智能合约的公共API规范，类似于OpenAPI规范。我们需要用ABI来调用合约函数。"],[20,"\n","24:\"7RrB\"|7:3"],[20,"\t合约/目录结构能协助我们导入合约ABI和地址："],[20,"\n","24:\"R4S1\"|7:3"],[20,"// functions/exec.js"],[20,"\n","24:\"gzSP\"|36:177"],[20,"\n","24:\"Om1h\"|36:177"],[20,"const { abis, addresses } = require('../contracts');"],[20,"\n","24:\"O8vg\"|36:177"],[20,"\n","24:\"PuXe\"|36:177"],[20,"const DummyStorageABI = abis.DummyStorage;"],[20,"\n","24:\"dbLw\"|36:177"],[20,"const DummyStorageAddress = addresses.DummyStorage;"],[20,"\n","24:\"cgdY\"|36:177"],[20,"这都是我们在接下来的函数部分中将要用到的。"],[20,"\n","24:\"v7Q0\"|7:3"],[20,"2. Functions","8:1"],[20,"\n","24:\"4tT7\"|7:3"],[20,"exec函数利用Ethers来加载合约ABI并调用智能合约："],[20,"\n","24:\"WkSd\"|7:3"],[20,"// Initialize contract"],[20,"\n","24:\"qLNG\"|36:177"],[20,"const contract = new ethers.Contract("],[20,"\n","24:\"DKmh\"|36:177"],[20," DummyStorageAddress,"],[20,"\n","24:\"buxw\"|36:177"],[20," DummyStorageABI,"],[20,"\n","24:\"wIm9\"|36:177"],[20," wallet,"],[20,"\n","24:\"VLwx\"|36:177"],[20,")"],[20,"\n","24:\"8Bgu\"|36:177"],[20,"\n","24:\"Ay9g\"|36:177"],[20,"// Call smart contract function " put="put" random_integer="Math.floor(Math.random()" returns="returns" a="a" random="random" integer="integer" from="from" to="to" quot="quot" tx="await" contract="contract" serverless="serverless" serverless-ethers="serverless-ethers" name:="name:" aws="aws" runtime:="runtime:" nodejs12="nodejs12" region:="region:" ap-southeast-1="ap-southeast-1" timeout:="timeout:" environment:="environment:" default_gas_price:="default_gas_price:" mnemonic:="mnemonic:" slack_hook_url:="slack_hook_url:" webhooks="webhooks" lambda="lambda" secrets="secrets" manager="manager" invoke="invoke" local="local" f="f" exec="exec" abis="abis" loaded="loaded" wallet="wallet" transaction="transaction" sent="sent" https:="https:" deploy="deploy" packaging="packaging" service="service" excluding="excluding" development="development" dependencies="dependencies" creating="creating" stack="stack" checking="checking" create="create" progress="progress" finished="finished" uploading="uploading" cloudformation="cloudformation" file="file" s3="s3" artifacts="artifacts" mb="mb" validating="validating" template="template" updating="updating" update="update" information="information" dev="dev" serverless-ethers-dev="serverless-ethers-dev" keys:="keys:" none="none" exec:="exec:" serverless-ethers-dev-exec="serverless-ethers-dev-exec" chatops="chatops" successmessage=":white_check_mark: Transaction sent https://ropsten.etherscan.io/tx/${tx.hash}" posttoslack="posttoslack" console="console" v5="v5" events="events" api="api" given="given" the="the" following="following" event:="event:" event="event" transfer="transfer" indexed="indexed" node="node" address="address" owner="owner" get="get" filter="filter" second="second" null="null" could="could" be="be" omitted="omitted" query="query" logs="contract.queryFilter(filter," block="block" latest="latest" print="print" out="out" all="all" values:=">" log="log" control="control">

function runMe() public {
require(block.timestamp >= lastTriggeredAt + 1 hour);
...
}

> npm install -g serverless
> serverless -v
x.x.x

service: serverless-ethers
provider:
name: aws
runtime: nodejs12.x
environment:
CHAIN_ID: 3
DEFAULT_GAS_PRICE: 60000000000

functions:
myFunc:
handler: functions/myFunc.handler
events:
- schedule: rate(2 hours)

// functions/myFunc.js
exports.handler = async function(event, context) {
// Do anything
};

# serverless.yml

functions:
myFunc:
handler: functions/myFunc.handler
events:
- schedule: rate(2 hours)

# serverless.yml

events:
- schedule: cron(0 12 * * ? *) # 12PM UTC

git clone [email protected]:yosriady/serverless-ethers.git
cd serverless-ethers
nvm use
npm install

├── contracts/
│ ├── abis/
│ ├── abis.js
│ └── addresses.js
├── functions/
│ └── exec.js
└── serverless.yml

// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.6.10;


contract DummyStorage {
event Write(address indexed source, uint256 value);


uint internal _currentValue;


function get() public view returns (uint) {
return _currentValue;
}


function put(uint value) public {
emit Write(msg.sender, value);
_currentValue = value;

├── contracts/
│ ├── abis/
│ │ └── DummyStorage.json
│ ├── abis.js
│ └── addresses.js

// functions/exec.js

const { abis, addresses } = require('../contracts');

const DummyStorageABI = abis.DummyStorage;
const DummyStorageAddress = addresses.DummyStorage

// Initialize contract
const contract = new ethers.Contract(
DummyStorageAddress,
DummyStorageABI,
wallet,
)

// Call smart contract function `put(uint)`
const RANDOM_INTEGER = Math.floor(Math.random() * 100); // returns a random integer from 0 to 99
const tx = await contract.put(RANDOM_INTEGER)

# serverless.yml

service: serverless-ethers
provider:
name: aws
runtime: nodejs12.x
region: ap-southeast-1
timeout: 30
environment:
DEFAULT_GAS_PRICE: 60000000000
MNEMONIC: ...
SLACK_HOOK_URL: ...

> serverless invoke local -f exec
Starting...
Contract ABIs loaded
Ethers wallet loaded
Contract loaded
Sending transaction...
:white_check_mark: Transaction sent https://ropsten.etherscan.io/tx/0x72204f07911a319b4e5f7eb54ad15ed666cfc1403b53def40c9d60188b176383
Completed
True

> serverless deploy
Serverless: Packaging service...
Serverless: Excluding development dependencies...
Serverless: Creating Stack...
Serverless: Checking Stack create progress...
........
Serverless: Stack create finished...
Serverless: Uploading CloudFormation file to S3...
Serverless: Uploading artifacts...
Serverless: Uploading service serverless-ethers.zip file to S3 (2.95 MB)...
Serverless: Validating template...
Serverless: Updating Stack...
Serverless: Checking Stack update progress...
.....................
Serverless: Stack update finished...
Service Information
service: serverless-ethers
stage: dev
region: ap-southeast-1
stack: serverless-ethers-dev
resources: 8
api keys:
None
endpoints:
None
functions:
exec: serverless-ethers-dev-exec
layers:
None

const successMessage = `:white_check_mark: Transaction sent https://ropsten.etherscan.io/tx/${tx.hash}`;
await postToSlack(successMessage);

// Given the following Event:
// event Transfer(bytes32 indexed node, address owner)

// Get the filter (the second null could be omitted)
const filter = contract.filters.Transfer(userAccount, null);

// Query the filter
const logs = contract.queryFilter(filter, 0, "latest"); // from block 0 to latest block

// Print out all the values:
logs.forEach((log) => {
console.log(log.args._to, log.args._value);
}

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本文来源：区块链大本营
原文标题：如何构建无服务器智能合约自动化项目

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编译者/作者：区块链大本营

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