Serverless Resolution Reminder

This application is my showcase project for the Udacity Cloud Developer Nanodegree.

The resolution reminder is an AWS Serverless Application where a user can pen down their ideas, feelings and inspired images.

Technology Stack

• AWS
  • Lambdas (serverless functions)
  • DynamoDB (database)
  • S3 (storage of images)
  • X-Ray (distributed tracing)
• Infrastructure as Code (IaC)
  • Serverless Framework
  • AWS CloudFormation
• Web Application Client
  • React
• Auth0
  • 3rd party OAuth integration

Functionality

• The application allows users to read, create, update, delete resolution ideas
• The application allows users to upload a file through S3 pre-signed URL
• The application only displays resolutions for a logged in user
• Authentication is implemented and does not allow unauthenticated access

Best Practices

• The business layer of the application is separated from data layer code for database access, file storage, and code related to AWS Lambda
• Application has sufficient monitoring with the help of X-Ray and winston
• HTTP requests are validated through using request validation in API Gateway
• RS256 (asymmetric) algorithm is applied to sign a JWT token
• Each Lambda function has its own set of permissions
• Individual packaging of Lambdas

Resolution item

Each resolution item contains the following fields:

• userId (string) - a unique id for a user which is parsed from Auth0 JSON Web Token
• itemId (string) - a unique id for an item
• title (string) - title of a resolution item (e.g. "Do more exercises")
• desc (string) - description of a resolution item
• createdAt (string) - date and time when an item was created
• modifiedAt (string) - date and time when an item was last modified
• attachmentUrl (string) (optional) - a URL pointing to an image attached to a resolution item

API Reference

Method	HTTP request	Description
List	Get /items	Lists all resolutions of the logged in user
Create	Post /items	Create a new resolution
Update	Put /items/{itemId}	Update an existed resolution
Delete	Delete /items/{itemId}	Delete an existed resolution
Get	Post /items/{itemId}/attachment	Get a S3 pre-signed URL for attachment

Local Debugging

Dynamodb

To deploy Dynamodb locally run the following commands:

cd backend

sls dynamodb start

A Dynamodb seed data is prepared and would applied automatically.

API Gateway and Lambda

To deploy API Gateway and Lambda locally run the following commands:

cd backend

sls offline

How to run the application

Backend

To deploy an application run the following commands:

cd backend

npm install

sls deploy -v

Client

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

Screenshots

• Deploy to AWS
• AWS CloudFormation Stack
• AWS X-Ray Service Map
• Auth0 Authentication