seankrail.dev's backend

My personal website's backend built using TypeScript, AWS CDK, and Rust, hosted on AWS Lambda and DynamoDB, and continuously deployed by GitHub Actions.

Right now, it just provides an endpoint to increment a count, but plan to host more interesting features and experiments in the future.

Development

There's a Lambda function written in Rust located at functions/counter. There you can run normal cargo commands to build, test, etc. You'll also need to install Cargo Lambda in your development environment. It's used to build a target for the Lambda environment.

cargo lambda build --release --arm64

This produces target/lambda/counter/bootstrap. This is referenced in our CounterStack at lib/counter-stack.ts. The target/lambda/counter directory is zipped, uploaded to S3, and then used to run the Lambda function.

The CDK components are split into three parts: bin/, lib/, test/. bin/ holds the CDK entrypoint. It instantiates our CDK App and creates the CounterStack (referencing lib/counter-stack.ts). The CDK CLI generates the CloudFormation templates from it. lib/ is where we define our CDK constructs and stacks referenced in bin/website-backend.ts. test/ holds the unit tests for lib/ resources.

For example, to build everything and synthesize the Cfn templates, run:

yarn build-function
yarn build
yarn cdk synth

Updating

Updating node via mise

There's a `.mise.toml in this project root, so all you need to run is:

mise use node@20
node -v
npm -v

Updating yarn

See https://yarnpkg.com/getting-started/install.

# assuming you have already run:
# corepack enable
yarn set version stable

Updating npm packages

yarn up -i '*' '@*/*'

Updating cargo crates

cargo update
cargo upgrade

Useful CDK commands

The cdk.json file tells the CDK Toolkit how to execute your app.

• yarn build compile typescript to js
• yarn watch watch for changes and compile
• yarn test perform the jest unit tests
• yarn cdk deploy deploy this stack to your default AWS account/region
• yarn cdk diff compare deployed stack with current state
• yarn cdk synth emits the synthesized CloudFormation template