# Between Web3 and Web2: SoulWallet's Backend Tech Stack--AWS Lambda On wtiring... ## Between Web3 and Web2: SoulWallet's Backend Tech Stack--AWS Lambda + Web3需要依赖Web2，这个是一个现状，未来也会很长期的现状，Web3不是真空，是Web的一个新形态应用而已。 + 许多Web3应用都会用到和Email、Twitter等等传统的Web2应用打交道，那如何设计一个随着应用复杂度增长而可伸缩，初期开发难度不高，后期可扩展的技术架构，来支撑这个桥接场景呢？我们以Email为例，其他Twitter也类似了，抛下一些思考和实践过程。 + 本文也是SoulWallet产品的Email验证服务作为后端服务，使用AWS Lambda快速搭建的过程，记录下来，分享给各位Web3 builder。 ### Mail技术选型 #### 应用背景 + Web3的钱包，需要拥有者设置自己或者他人可信的Email，作为Guardian，整个业务过程包括: + 验证邮件可信（发验证码+收到验证码verify）、验证安全签名DKIM（可选，后期加）、作为Guardian参与Recvery。 #### 可能的函数 get4RandomNumber sendMail2Address verify4RandomNumber sendRecoveryHashMail verifyDKMIHash2Recovery get6RandomNumber sendMail2BatchAddress verify6RandomNumber 使用API Gateway调用，先用OAuth2？ #### 评估 + 1>AWS Lambda+ AWS SES + 好处：按需付费，开发技术栈稳定简单（相对），未来可扩展，坏处：不是去中心，长期可能有一些隐患 + 2>Docker化使用Hanko + 坏处：技术难度略高，需要自己修改定制，好处：标准Docker+配置，可以部署和扩展在任何地方，去中心 ### 分析 + 1.中心化服务，例如AWS S3、Google Firebase会长期存在，并且服务也较为稳定。 + 2.一些非核心的应用场景，例如邮件服务、验证服务等的，可以放在中心化服务器。 + 3.用Serverless快速搭建服务，并且沉淀出模型，形成快速可迁移的能力，也是某种层次的去中心。 + 4.对于非核心服务的部分中心化，最坏情况下需要不能影响客户的核心体验（这个要评估和实验）。 + 5.所有代码如果开放开源，则可以用类似Stake方式，让更多节点把安全中心去中心化，则更稳定和去中心。 ### 设计 #### 交互泳道图 ![email-flow.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1662378609205/9lxWI29nr.png align="left") ### 开发 #### 准备 1. 进入AWS，搜索Lambda服务，进入，创建一个Lambda function。 几个图片参考下，很简单 ![截屏2022-09-05 11.15.41.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1662378694247/zWLVM9d11.png align="left") ![截屏2022-09-05 11.16.36.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1662378699655/KWgHzcOKG.png align="left") ![截屏2022-09-05 11.16.49.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1662378705157/QR-XjO0nj.png align="left") ![截屏2022-09-05 11.28.59.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1662378711147/p8N8u6eQk.png align="left") ![截屏2022-09-05 11.29.06.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1662378719227/i4QT36y05.png align="left") ![截屏2022-09-05 11.29.13.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1662378723904/bXvjCtDAG.png align="left") 2. Mac 下安装[SAM](https://docs.aws.amazon.com/zh_cn/serverless-application-model/latest/developerguide/serverless-sam-cli-install-mac.html): ``` brew tap aws/tap brew install aws-sam-cli ``` 注意，我遇到了404问题，解决办法 ``` brew install aws-sam-cli ==> Downloading https://mirrors.ustc.edu.cn/homebrew-bottles/bottles/python%403.8-3.8.12_1.monterey.bottle.tar.gz curl: (22) The requested URL returned error: 404 Warning: Bottle missing, falling back to the default domain... ==> Downloading https://ghcr.io/v2/homebrew/core/python/3.8/manifests/3.8.12_1 Already downloaded: /Users/jason/Library/Caches/Homebrew/downloads/61f42b7874c869da77ca6a2c68ce8fba17392d585f49a57c4f98b846e4255d4f--python@3.8-3.8.12_1.bottle_manifest.json ==> Downloading https://ghcr.io/v2/homebrew/core/python/3.8/blobs/sha256:9003ba90da12f509084675de2ac639356aa929f99483115250b7cfb154ade246 Already downloaded: /Users/jason/Library/Caches/Homebrew/downloads/1277a706a480613882eed92d3a3d8d64b8685f2ebc814c888765c4044ce32cd9--python@3.8--3.8.12_1.monterey.bottle.tar.gz ==> Downloading https://github.com/aws/aws-sam-cli/releases/download/v1.56.0//aws-sam-cli-1.56.0.sierra.bottle.tar.gz ==> Downloading from https://objects.githubusercontent.com/github-production-release-asset-2e65be/92205085/29934f42-b9b2-46f8-8901-4cc832ca4988?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIWNJYA ######################################################################## 100.0% ==> Installing aws-sam-cli from aws/tap ==> Installing dependencies for aws/tap/aws-sam-cli: python@3.8 ==> Installing aws/tap/aws-sam-cli dependency: python@3.8 ==> Pouring python@3.8-3.8.12_1.monterey.bottle.tar.gz Error: No such file or directory @ rb_sysopen - /Users/jason/Library/Caches/Homebrew/downloads/43fd497f6cd5d3be88e46f093783bcfb87796f443dbf38b2060d8b336e25d8ba--python@3.8-3.8.12_1.monterey.bottle.tar.gz ``` 复制一份即可 ``` cp -a /Users/jason/Library/Caches/Homebrew/downloads/1277a706a480613882eed92d3a3d8d64b8685f2ebc814c888765c4044ce32cd9--python@3.8--3.8.12_1.monterey.bottle.tar.gz /Users/jason/Library/Caches/Homebrew/downloads/43fd497f6cd5d3be88e46f093783bcfb87796f443dbf38b2060d8b336e25d8ba--python@3.8-3.8.12_1.monterey.bottle.tar.gz ``` 3. ``` #Step 1 - Download a sample application sam init #Step 2 - Build your application cd sam-app sam build #Step 3 - Deploy your application sam deploy --guided ``` 初始化过程，可参考 ``` cd ~/Dev/Projects/soulwallet-backend jason@HuifengjiaodeMacBook-Pro ~/Dev/Projects/soulwallet-backend (main) » ls jason@HuifengjiaodeMacBook-Pro README.md ~/Dev/Projects/soulwallet-backend (main) » sam init jason@HuifengjiaodeMacBook-Pro SAM CLI now collects telemetry to better understand customer needs. You can OPT OUT and disable telemetry collection by setting the environment variable SAM_CLI_TELEMETRY=0 in your shell. Thanks for your help! Learn More: https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-sam-telemetry.html ``` More： ``` You can preselect a particular runtime or package type when using the `sam init` experience. Call `sam init --help` to learn more. Which template source would you like to use? 1 - AWS Quick Start Templates 2 - Custom Template Location Choice: 1 Choose an AWS Quick Start application template 1 - Hello World Example 2 - Multi-step workflow 3 - Serverless API 4 - Scheduled task 5 - Standalone function 6 - Data processing 7 - Infrastructure event management 8 - Lambda EFS example 9 - Machine Learning Template: 1 Use the most popular runtime and package type? (Python and zip) [y/N]: n Which runtime would you like to use? 1 - dotnet6 2 - dotnet5.0 3 - dotnetcore3.1 4 - go1.x 5 - graalvm.java11 (provided.al2) 6 - graalvm.java17 (provided.al2) 7 - java11 8 - java8.al2 9 - java8 10 - nodejs16.x 11 - nodejs14.x 12 - nodejs12.x 13 - python3.9 14 - python3.8 15 - python3.7 16 - python3.6 17 - ruby2.7 18 - rust (provided.al2) Runtime: 10 What package type would you like to use? 1 - Zip 2 - Image Package type: 1 Based on your selections, the only dependency manager available is npm. We will proceed copying the template using npm. Select your starter template 1 - Hello World Example 2 - Hello World Example TypeScript Template: 1 Would you like to enable X-Ray tracing on the function(s) in your application? [y/N]: y X-Ray will incur an additional cost. View https://aws.amazon.com/xray/pricing/ for more details Project name [sam-app]: testSAM Cloning from https://github.com/aws/aws-sam-cli-app-templates (process may take a moment) ``` Generating application: ----------------------- Name: testSAM Runtime: nodejs16.x Architectures: x86_64 Dependency Manager: npm Application Template: hello-world Output Directory: . Next steps can be found in the README file at ./testSAM/README.md Commands you can use next ========================= [*] Create pipeline: cd testSAM && sam pipeline init --bootstrap [*] Validate SAM template: sam validate [*] Test Function in the Cloud: sam sync --stack-name {stack-name} --watch 进入目录，build： ``` cd testSAM jason@HuifengjiaodeMacBook-Pro ~/Dev/Projects/soulwallet-backend/testSAM (main*) » ls jason@HuifengjiaodeMacBook-Pro README.md events hello-world template.yaml ~/Dev/Projects/soulwallet-backend/testSAM (main*) » vim build.sh jason@HuifengjiaodeMacBook-Pro ~/Dev/Projects/soulwallet-backend/testSAM (main*) » chmod +x *.sh jason@HuifengjiaodeMacBook-Pro ~/Dev/Projects/soulwallet-backend/testSAM (main*) » ./build.sh jason@HuifengjiaodeMacBook-Pro Your template contains a resource with logical ID "ServerlessRestApi", which is a reserved logical ID in AWS SAM. It could result in unexpected behaviors and is not recommended. Building codeuri: /Users/jason/Dev/Projects/soulwallet-backend/testSAM/hello-world runtime: nodejs16.x metadata: {} architecture: x86_64 functions: HelloWorldFunction Running NodejsNpmBuilder:NpmPack Running NodejsNpmBuilder:CopyNpmrcAndLockfile Running NodejsNpmBuilder:CopySource Running NodejsNpmBuilder:NpmInstall Running NodejsNpmBuilder:CleanUpNpmrc Running NodejsNpmBuilder:LockfileCleanUp Build Succeeded Built Artifacts : .aws-sam/build Built Template : .aws-sam/build/template.yaml Commands you can use next ========================= [*] Validate SAM template: sam validate [*] Invoke Function: sam local invoke [*] Test Function in the Cloud: sam sync --stack-name {stack-name} --watch [*] Deploy: sam deploy --guided ``` ### 部署 ### Invoke ### 其他 #### 参考 AWS SES ：https://aws.amazon.com/cn/ses/ Lambda Dev Progress：https://docs.aws.amazon.com/toolkit-for-vscode/latest/userguide/serverless-apps.html#serverless-apps-create #### 补充 后续因为Security Center定义发生变化，承载了更多的业务功能，所以上述设计工作架构变化不大，但是开发工作量更多了。 #### 技术栈 Web2的设计思维，是中心化大集群的业务场景，因此会把复杂场景拆解为微服务，而后来发现，微服务还不够（大厂的业务流程太复杂了），因此进化出了FAAS，进一步拆解服务，可以理解为微服务的下一层。研发团队不需要关注任何和业务无关的（组件、环境、扩容、分流等等），只需要写自己的业务函数，其他交给FAAS服务来搞定。 而Web3的Decentralized，从某种程度上来看，抽象出业务行为，然后在任何可以提供FAAS的云服务运行自己的服务，也是一种阶段选择，因为不变的业务和具体业务实现代码，是非常容易迁移的。 当然，如果Web3不被法律认可，所有中心化服务拒绝Web3，那也是一种可能，但从发展和技术角度看，可能性不高。