AWS-Event-Announcement-project

 Description about the project:

This project is about building a serverless Event Announcement application using AWS. the application allow users to create events , list them on a website and send notification to subscribers.

I built this project to learn and showcase how AWS services can work together in real-world scenarios. it demonstrates skills in cloud computing such as :

• Hosting a static website on Amazon S3
• Storing data in DynamoDb
• Building serverless APIs with API Gateway + Lambda
• Sending notification via SNS

##The main goal of this project was to gain hands on experience with AWS cloud services .

# Services used in this project 

• S3
• Dynamo Db
• SNS
• Lambda
• API Gateway

# Architecture Diagram👉

#  For codes and files reference github 👉(https://github.com/bilsgotchills/aws-event-announcement.git)

Step 1 : Create a S3 Bucket 

• Enable Static website hosting in S3
• Upload your index.html file

Step 2: Create a DynamoDB 

• Table name : events
• Partition Key :eventId (string)
• Attributes : eventName, eventDate, and eventDescription.

Step 3:Created a IAM role name "dynamo-s3-sns"

• SNS full Access
• S3 full Access
• BasicLambdaExecutionRole
• AmazonDynamoDbBfull access 

Step 4: Create a SNS topic

• Subscribe with Email/SMS

Step 5: Create 2 lambda function 

1. Create-Event-lambda
2.  List-event-lambda
   

Step 6: Set the Enviroment Variables in lambda and attach the role .

Step 7: I used API Gateway (HTTP) to expose two endpoints for the Event Announcement App:

• POST /create -- Integrate it with create-Event-lambda (invokes create event lambda)
• GET /list -- Integrate it with list-event-lambda (invokes list event lambda)

👉 I chose HTTP API because its simple , low-latency and easy to integrate with Lambda for this serverless app

👉 Configure CORS : We need to set our Frontend hosted on S3 and our backend hosted on API Gateway on the same origin ( domain+ port+ protocol)  otherwise our browser will block requests from our S3 page to API Gateway.

Note: For better security put your S3 bucket URL in "Allow-Origin" .

Testing of website:

(a) Copy the Bucket Website Endpoint form S3 and paste it on browser.

(b) Create a Event 

(c) If event created is successfull a newly created event will be shown in Upcoming events .

(d) DynamoDB will store the data related to events .

(e) SNS will send notifictaion to subscribers via mail.

(f) Pics related to event will be stored in S3.  

Problems faced :

(a) Newly created events appeared below older ones 

     Solution: Added createdAt timestamp in createEvent-lambda

(b) uuid package not included in Lambda deployment

     Solution: Instead of uuid we can use Node's built in crypto library to generate IDs

Learnings :

• Learned to read CloudWatch logs to debug lambda features.
• Understood how CORS actually work .
• Learned that environment variables name in AWS are case sensitive.
• Experienced the difference between HTTP API and REST API.