Using functions for REST APIs

This lesson will walk through using functions as a REST backend.

• Lesson Steps
• Other examples
• Complete code

Lesson Steps

1. Create a netlify.toml file in your project.

   The netlify.toml file is where we configure how the site builds and where your serverless functions live.

2. In netlify.toml, add a [build] section and add publish = "site" and functions = "functions" values

3. We need to create this site in Netlify

   Open your terminal and run the following command:

   netlify init --manual

   Choose "create & configure a new site", then add a site name or hit enter for one to be generated for you.

4. Create your API function

   Create a function name api in the /functions folder

5. In functions/api.js, we are going to setup our API router

   Use the event.path & event.httpMethod to determine how to handle the request

6. Create your API function

   Create a function name api in the /functions folder

   "See code"

   exports.handler = async (event, context) => {
     const path = event.path.replace(/\.netlify\/functions\/[^/]+/, '')
     const segments = path.split('/').filter(e => e)
   
     switch (event.httpMethod) {
       case 'GET':
         // GET /.netlify/functions/api
         if (segments.length === 0) {
           return api.readAll(event, context)
         }
         // GET /.netlify/functions/api/123456
         if (segments.length === 1) {
           event.id = segments[0]
           return api.read(event, context)
         } else {
           return {
             statusCode: 500,
             body: 'too many segments in GET request'
           }
         }
       // POST /.netlify/functions/api
       case 'POST':
         return api.create(event, context)
       // PUT /.netlify/functions/api/123456 
       case 'PUT':
         if (segments.length === 1) {
           event.id = segments[0]
           return api.update(event, context)
         } else {
           return {
             statusCode: 500,
             body: 'invalid segments in POST request, must be /.netlify/functions/api/123456'
           }
         }
       // DELETE /.netlify/functions/api/123456
       case 'DELETE':
         if (segments.length === 1) {
           event.id = segments[0]
           return api.delete(event, context)
         } else {
           return {
             statusCode: 500,
             body: 'invalid segments in DELETE request, must be /.netlify/functions/api/123456'
           }
         }
       // Fallthrough case
       default:
         return {
           statusCode: 500,
           body: 'unrecognized HTTP Method, must be one of GET/POST/PUT/DELETE'
         }
     }
   }

7. Create a /functions/methods folder

   We will add in our logic to handling the different routes here

8. Install the function dependencies

   Change directories into your functions folder and install the dependencies

   cd functions && npm install

   This will install the fauandb sdk our functions will use to talk to our database.

   Install the faunaDB addon

   netlify addons:create fauna
   

   Scaffold our database schema

   npm run setup
   

9. Deploy the site

   Open your terminal and run the following command:

   netlify deploy -p

   Visit the frontend to verify your api works!

Other examples

• Using Express
• Using Serverless + API gateway

Complete code

If you need help or get stuck refer to the completed code of this lesson

View Complete Code