README.md

AWS: API, Dynamo and Lambda

Mirroring our previous efforts in Express, today, we will be wiring up a completely serverless, let fully functional, CRUD-Enabled API.

Learning Objectives

Students will be able to

Describe and Define

• AWS API Gateway
• How to trigger Lambda Functions in response to an API request
• The differences between HTTP and REST APIs at AWS
• The differences between DynamoDB and Mongo

Execute

• Creation of a DynamoDB Table
• Creation of a Lambda function that can operate on a DynamoDB Table
• Usage of Dynamoose in a NodeJS Lambda Function

Today's Outline

Notes

Creating a serverless API: Checklist

• IAM User role with access to Lambda and DynamoDB Full Access
• Dynamo DB Table Created
• Lambda function(s) that use Dynamoose to attach to the table
  • Created with the correct IAM Role (Step 1)
• API Endpoints that all the appropriate functions for each action type

Creating a Dynamo DB Table at AWS

1. Open the DynamoDB Dashboard
2. Choose Create Table
3. Name your table
4. Choose a field name to use as primary key
   • Generally, "id", and you'll need to supply this when you add records

Working with Dynamo from Node

When writing code that connects to a Dynamo Database, you'll need to know your AWS credentials and install dynamoose as a dependency

https://dynamoosejs.com/getting_started/Introduction

Create a Schema with Dynamoose

This is just like Mongoose!

'use strict';

const dynamoose = require('dynamoose');

const friendsSchema = new dynamoose.Schema({
  'id': String,
  'name': String,
  'phone': String,
});

module.exports = dynamoose.model('friends', friendsSchema);

Write your Lambda Function (or any JS) to use your schema...

Again, this is very similar to Mongoose and Mongo

const contentModel = require('./curriculum.schema.js');

async function findRecord(id) {
  const content = await contentModel.query("id").eq(id).exec();
  console.log(content[0]);
}

async function saveRecord(name, phone) {
  const id = uuid();
  const record = new contentModel({ id, name, phone });
  const data = await record.save();
  console.log(data);
}

Create API Endpoints

1. At API Gateway, create a new HTTP API
2. Once created, define a route endpoint for each REST method
3. Connect each endpoint to a lambda

As your routes are invoked by users, those lambda's will fire, with the event receiving any POST or QUERY data