Presigned Multipart Go Backend Service

This repository provides a Go backend service for initiating multipart uploads, generating presigned URLs for part uploads, and completing multipart uploads to Amazon S3.

Features:

• Implements a multi-part upload workflow for large files.
• Provides API endpoints for initiating, pre-signing individual parts, and completing uploads.
• Uses AWS S3 for storage.

Requirements:

• Go 1.17 or later
• AWS account with S3 bucket

Installation:

1. Clone this repository.
2. Create a .env file in the project root directory with the following environment variables:
   • AWS_ACCESS_KEY_ID: The access id with s3 permissions.
   • AWS_SECRET_ACCESS_KEY: The secret access key with s3 permissions.
   • AWS_REGION: The AWS region where your S3 bucket is located.
   • AWS_BUCKET: The name of your S3 bucket.
   • PORT: Server running port

Running the Service:

1. Build the service:

   make build

2. Run the service:

   ./bin/service

This will start the service and listen for requests on port 8080.

API Endpoints:

• /initiate (GET): Initiates a multipart upload for a file.

  • Query parameter: key (string): The name of the file to upload.
  • Response: JSON object containing the uploadId for the multipart upload.

• /presigned (GET): Generates a presigned URL for uploading a specific part of a multipart upload.

  • Query parameters:
    • key (string): The name of the file to upload.
    • uploadId (string): The uploadId obtained from the /initiate endpoint.
    • partNumber (int): The part number of the part to upload.
  • Response: JSON object containing the uploadUrl for the part upload, the uploadId, the partNumber, and the expiresAt timestamp for the presigned URL.

• /complete (POST): Completes a multipart upload by providing the ETags of all uploaded parts.

  • Request body: JSON object with a parts array containing objects with PartNumber (int) and ETag (string) keys for each uploaded part.
  • Query parameters:
    • key (string): The name of the file that was uploaded.
    • uploadId (string): The uploadId obtained from the /initiate endpoint.
  • Response: Status code 200 if the upload is completed successfully.

CORS Configuration:

The service is configured with CORS (Cross-Origin Resource Sharing) to allow requests from any origin. This configuration might need to be adjusted depending on your specific deployment environment.

Security Considerations:

• This example uses environment variables for sensitive information like AWS credentials. Consider using a more secure method for storing and managing secrets in production environments.
• The CORS configuration allows requests from any origin. This configuration should be tightened for production environments.

Contributing:

We welcome contributions to this project! Please see the CONTRIBUTING.md file for guidelines on how to contribute.

License:

This project is licensed under the MIT License. See the LICENSE file for details.