Object Detection WebApp on AWS

Project Overview

This project involves building a cloud-based object detection system using AWS services. The system will allow users to upload images, process them using Amazon Rekognition, and store the detected labels in a DynamoDB table. The architecture leverages AWS Lambda, API Gateway, S3, EC2, and Auto Scaling to create a scalable and efficient solution.

Architecture Diagram

Project Flow

1. User Interface:

   Users access a web interface hosted on an EC2 instance. This interface provides a form to upload images.

2. Image Upload:

   When a user selects an image and submits the form, the web interface sends a request to an API Gateway endpoint to get a pre-signed URL for uploading the image to an S3 bucket.

3. Generate Pre-Signed URL:

   An AWS Lambda function (LambdaPreSignedURL) is invoked by the API Gateway to generate a pre-signed URL for the S3 bucket. The pre-signed URL is returned to the web interface.

4. Upload Image to S3:

   The web interface uses the pre-signed URL to upload the image directly to the S3 bucket (ImageS3Bucket).

5. S3 Event Notification:

   Once the image is uploaded to the S3 bucket, an S3 event is triggered (configured manually to avoid circular dependencies). This event invokes another Lambda function (LambdaRekognitionLabels).

6. Image Processing with Rekognition:

   The LambdaRekognitionLabels function processes the image using Amazon Rekognition to detect labels. The detected labels are then formatted and stored in a DynamoDB table (LabelsDynamoDBTable).

7. Store Labels in DynamoDB:

   The labels detected by Rekognition are stored in the DynamoDB table along with the image name as the primary key.

8. Auto Scaling and EC2 Hosting:

   The web interface is hosted on an EC2 instance, which is part of an Auto Scaling Group (MyAutoScalingGroup) to ensure high availability and scalability. The EC2 instances are launched using a predefined launch template (MyLaunchTemplate).

9. Security and Permissions:

   The project uses various IAM roles and policies to ensure that AWS services interact securely. This includes permissions for Lambda functions to access S3, Rekognition, DynamoDB, and CloudWatch Logs.

AWS CloudFormation Template Components

• Parameters:
  • VPCID: VPC where resources will be launched.
  • SubnetIds: List of subnet IDs for the Auto Scaling Group.
• Resources:
  • ImageS3Bucket: S3 bucket to store uploaded images with CORS configuration.
  • LabelsDynamoDBTable: DynamoDB table to store image labels.
  • LambdaPreSignedURL: Lambda function to generate pre-signed URLs for S3 uploads.
  • LambdaRekognitionLabels: Lambda function to process images using Rekognition and store labels in DynamoDB.
  • MyApiGatewayRestApi: API Gateway to handle requests.
  • ApiGatewayResourceUpload: API Gateway resource for upload.
  • ApiGatewayMethodUploadGet: Method for API Gateway to get pre-signed URL.
  • ApiGatewayCORS: CORS configuration for API Gateway.
  • ApiGatewayDeploymentProd: Deployment configuration for API Gateway.
  • LambdaInvokePermission: Permission for API Gateway to invoke Lambda.
  • EC2SecurityGroup: Security group for EC2 instances.
  • ALBSecurityGroup: Security group for Application Load Balancer.
  • MyLaunchTemplate: Launch template for EC2 instances.
  • MyAutoScalingGroup: Auto Scaling group configuration.
  • ScalingPolicy: Scaling policy for Auto Scaling group.
  • LambdaPermissionForS3: Permission for S3 to invoke Lambda.
  • LambdaPreSignedIAMRole: IAM role for LambdaPreSignedURL.
  • LambdaRekognitionIAMRole: IAM role for LambdaRekognitionLabels.
• Outputs:
  • ApiUrl: URL of the API Gateway.

Deployment and Manual Configuration Steps

1. Deploy CloudFormation Stack:

   Deploy the CloudFormation stack using the provided template to create all necessary resources.

2. Configure S3 Event Notification:

   Manually configure the S3 bucket to trigger the LambdaRekognitionLabels function on object creation events to avoid circular dependencies.

3. Update Web Interface:

   Ensure the web interface is correctly pointing to the deployed API Gateway URL for requesting pre-signed URLs.