Your first cloud function

The core feature of serverless you'll use are cloud functions. They make things happen. We'll take a look at 3 providers and how they make cloud functions working.

Starting with the good old hello world 😊

Vercel

Vercel uses an ExpressJS-like cloud functions and filename routing. Files in /api turn into cloud functions at the same path as their name.

Exercise

Create a new project with an /api directory and add a JavaScript file. Export an async method (using module.exports = ) that accepts a req and res argument.

Use the .status and .send methods on res to return a string.

Deploy your project with the vercel command. Use default answers to prompts.

Solution

Netlify

Netlify's cloud functions behave as a thin wrapper on AWS Lambda. You get a more universal environment and codebase at the cost of more configuration work.

Unlike Vercel, Netlify supports certain event-driven functions.

Exercise

Create a new project with an /functions directory and add a JavaScript file. Export an async handler method (using exports.handler = ) that accepts an event argument.

Return an object with a statusCode and a body.

{
    statusCode: 200,
    body: "Hello world"
}

Add a netlify.toml config file at the root:

[build]
    functions = "functions"

Deploy with netlify deploy, set up as a new project.

Solution

AWS Lambda

AWS Lambda gives you access to the full power of serverless and is also the most cumbersome to use. You can use their UI but I don't recommend it.

Using a code-as-infra approach gets you close to the Netlify and Vercel developer experience. You can use AWS's official CloudFormation tooling, but I find Serverless Framework a more welcoming approach.

Serverless Framework is open source tooling working on top of CloudFormation. Makes common operations easier and lets you drop down to CloudFormation when you need more power.

Exercise

Clone the serverless-workshop-exercises GitHub repository and start with exercise-1. You get a repository configured for serverless and I've added build and deploy scripts.

It's set up with TypeScript - helps cut down debugging time, you'll see.

Create a src/hello.ts file that exports a handler function. Return a response object just like in the Netlify example.

Deploy with yarn deploy or npm run deploy.

PS: if you're not well versed in TypeScript yet, don't worry. We won't use anything crazy at this workshop.

Solution

https://github.com/Swizec/serverless-workshop-exercises/tree/exercise-1-solution