ReBarrington / AWS-Tutorial

AWS Lambda & DynamoDB Tutorial

YouTube Tutorial by Cloud Path Here

A step-by-step tutorial on how to write AWS Lambda functions in NodeJS to get and set data in DynamoDB. We will create a Users table with two lambda functions: GetUserData and PutUserData.

Getting Started

• Create a table in DynamoDB: Users
  • Primary Key can be id, a string
  • Add 1 item to the table
• Create an IAM role to give our lambda permissions to work with the table
  • You will need the ARN from the table's overview
  • Create Role
    • AWS service
    • Lambda
    • Permissions: AWSLambdaBasicExecutionRole
    • Keys: optional. But useful if you have lots of roles and want to organize/search
    • Add Inline Policy to Role after creation
      • Service: DynamoDB
      • Actions: GetItem, PutItem
      • Resources: specific, paste in ARN
      • name policy
• Create Lambda Function
  • Use the exisiting role just created.
  • The Designer Tab allows you to specify triggers (We will set up API Gateway later)
  • Not recommended to edit code directly in the interface. Use VSC.
  • AWS Lambda Boilerplate Snippets is a recommended extension
    • lambda-aws will scaffold a starting function
  • aws-sdk is imported
  • You can view the DynamoDB API to better understand how to retrieve items from it. Search for GetItem to learn how to model the getUserData function
  • After function has been written. Copy and paste to Lambda interface.
• Test Lambda Function
  • Configure Test Event, deploy, test

Amazon API Gateway

• We're using API Gateway to create a simple REST API to interact with our lambda functions to get/set user data.
• API Gateway will call our lambda functions, which will in turn get/set data in the database.
• Select build REST API
• Edge optimized
• Actions > Create Resource
• Actions > Create Method

  • GET

    • Checking the Use Lambda Proxy Integration box will allow access to request parameters/body
    • Choose Lambda Function: getUserData
    • Clicking Method Request will allow extra options
      • Authorization: AWS_IAM allows you to create authorization on who can access API
      • Request Validator: Validate body, query string parameters, and headers
    • Add content-type header

  • test endpoint with query strings and header: content-type: application/json

  • POST

    • Let's create a new model
    • Link to API Gateway models docs
    • After creating model, add to request body in POST settings