Udacity - Cloud Developer Nanodegree Project 4

Functionality of the application

The application allows creating/removing/updating/fetching TODO items. Each TODO item can optionally have an attachment image. Each user only has access to TODO items that he/she has created.

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Implemented functions

The following lambda functions have been implemented (and set up in serverless.yml):

• Auth: Lambda authorizer (formerly custom authorizer)
• GetTodos: retrieves all todos for
• GetTodo: retrieves one todo (by id)
• CreateTodo: creates a new todo item
• UpdateTodo: updates a todo item
• DeleteTodo: removes a todo item
• GenerateUploadUrl: returns a signed url for uploading an image file to AWS S3

The JSON shape of a todo item

  {
    "todoId": "123",
    "createdAt": "2019-07-27T20:01:45.424Z",
    "name": "Buy milk",
    "dueDate": "2019-07-29T20:01:45.424Z",
    "done": false,
    "attachmentUrl": "http://example.com/image.png"
  }

All functions are already connected to appropriate events from API Gateway. An id of a user can be extracted from a JWT token passed by a client.

Authentication is implemented with Auth0 (using asymmetrically encrypted JWT tokens).

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Frontend

The client folder contains a web application that can use the API that should be developed in the project. The apiId binding in config.ts should be set to the correct value.

This file configures your client application just as it was done in the course and contains an API endpoint and Auth0 configuration:

const apiId = '...' API Gateway id
export const apiEndpoint = `https://${apiId}.execute-api.us-east-1.amazonaws.com/dev`

export const authConfig = {
  domain: '...',    // Domain from Auth0
  clientId: '...',  // Client id from an Auth0 application
  callbackUrl: 'http://localhost:3000/callback'
}

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How to run the application

Backend

To deploy an application run the following commands: export NODE_OPTIONS=--max_old_space_size=8192

cd backend
npm install
sls deploy -v

Frontend

To run a client application first edit the client/src/config.ts file to set correct parameters. And then run the following commands:

cd client
npm install
npm run start

This should start a development server with the React application that will interact with the serverless TODO application.

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Monitoring

Distributed tracing

X-Ray tracing has been set up

Logging

The starter code came with a configured Winston logger that creates JSON formatted log statements. It is used to write log messages like this:

import { createLogger } from '../../utils/logger'
const logger = createLogger('auth')

// You can provide additional information with every log statement
// This information can then be used to search for log statements in a log storage system
logger.info('User was authorized', {
  // Additional information stored with a log statement
  key: 'value'
})

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Postman collection

An alternative way to test your API, you can use the Postman collection that contains sample requests. You can find a Postman collection in this project.