63-fastapi-s3-upload

63 - File Upload & S3 storage API

What It Does

A FastAPI project that handles parsing multipart/form-data for file uploads. It abstracts the storage layer into a repository (storage.py) so you can easily switch between local disk storage (for dev) and AWS S3 (for production). The web frontend features a drag-and-drop HTML5 unified interface to test file creation.

Project Structure

63-fastapi-s3-upload/
  main.py            # FastAPI Entry point
  storage.py         # Abstracted Storage layer (Local Disk vs AWS S3)
  routes/
    files.py         # Routes handling file I/O
  uploads/           # Local folder storing dev files
  index.html         # Unified single-file Frontend (Drag and drop)
  requirements.txt   # Dependencies
  README.md          # This file

Setup and Run

1. Install dependencies

pip install -r requirements.txt

2. Start the Server

uvicorn main:app --reload

3. Open the Frontend

Open index.html directly in your browser. Since it operates completely client-side in terms of layout, you can just click on the file in your OS, no need for http.server.

Example Output

{
  "info": "2 files uploaded successfully",
  "filenames": [
    "c8a1b2_document.pdf",
    "f2e4d9_image.png"
  ]
}

Core Concepts

• FastAPI UploadFile / File: Effectively parsing binary files.
• aiofiles: Writing binary files to local disk asynchronously so the main event loop isn't blocked.
• Repository Pattern: We place the actual "save logic" inside storage.py. Here we use local disk logic, but boto3 for S3 is mentioned so a developer can switch depending on environment variables.
• Serving Static Files: Using fastapi.staticfiles to serve previously uploaded images.