Image Resizing Service

A Go-based service that resizes images from provided URLs and serves them through a REST API. The service supports both synchronous and asynchronous processing modes.

Features

• Resize images from any public URL
• Support for both synchronous and asynchronous processing
• LRU caching for processed images
• Configurable timeouts and processing delays
• Browser-like User-Agent for better compatibility

Prerequisites

• Go 1.16 or later
• Air (for development with hot reload)
• HTTPie (for testing, or use curl)

Installation

1. Clone the repository:

git clone https://github.com/cmin764/image-resize.git
cd image-resize

2. Install Air for development:

go install github.com/air-verse/air@latest

3. Install project dependencies:

go mod download

Configuration

Create a .env file in the project root by copying the template:

cp .env.template .env

Then edit the .env file with the following settings:

# Image processing timeout in seconds (how long to wait for an image to be processed)
IMAGE_PROCESSING_TIMEOUT=1

# Simulated processing duration in seconds (for testing)
IMAGE_PROCESSING_DURATION=3

Running the Server

Development Mode (with hot reload)

# Try this first
air

# If the above doesn't work, use the full path
~/go/bin/air

Production Mode

go run .

The server will start on http://localhost:8080

API Usage

Resize Images

Send a POST request to /v1/resize with a JSON body containing the image URLs and desired dimensions:

# Synchronous mode (default)
http POST ":8080/v1/resize" @data/req.json

# Asynchronous mode
http POST ":8080/v1/resize?async=true" @data/req.json

Example request body:

{
  "urls": [
    "https://example.com/image1.jpg",
    "https://example.com/image2.jpg"
  ],
  "width": 200,
  "height": 0  // 0 maintains aspect ratio
}

Access Resized Images

After processing, access the resized images at:

http://localhost:8080/v1/image/{image-id}.jpeg

Response Handling

Synchronous Mode

• Returns:
  • 200 OK when all images are served straight from the cache
  • 201 Created when new images are processed and saved to cache

Asynchronous Mode

• Returns 202 Accepted immediately (later processing)

Resized image retrieval

Check individual image URLs for status.

• 102 Processing: Image is still being processed
• 200 OK: Image is ready and retrieved
• 404 Not Found: Image processing failed and not found in the cache

Example Workflow

1. Send resize request:

http POST ":8080/v1/resize?async=true" @data/req.json

2. Check image status:

http http://localhost:8080/v1/image/AQPdOTElKSNH_piyJSCR4p1yMMRC1omE-mClICKUoks=.jpeg

If status is 102, wait and retry until you get 200 (or a 404 if the process failed in the meantime)

Improvements

See improvements for a list of potential fixes, including:

• Adding comprehensive test coverage
• Performance optimizations
• Security enhancements
• Additional features
• Infrastructure improvements