🎉 Imagehoster Go Rewrite Announcement

We are thrilled to announce that the Go language rewrite of Imagehoster, the image hosting service for the Steem blockchain, is now complete and ready for testing and deployment!

📋 Project Overview

Imagehoster is a decentralized image hosting service designed specifically for the Steem blockchain, allowing Steem users to upload images through signature verification, with features for image proxying, transformation, and avatar hosting. This rewrite completely refactors the original Node.js/TypeScript codebase into Go, delivering significant performance improvements and enhanced maintainability while maintaining 100% API compatibility.

✨ Core Features

Complete Feature Implementation

• ✅ Image Upload - Secure upload with Steem signature verification
• ✅ Image Serving - Efficient image storage and retrieval
• ✅ Image Proxy & Transformation - Resize and format conversion support
• ✅ User Avatar Service - Avatar hosting for Steem users
• ✅ Blacklist Management - Redis-driven blacklist checking (coordinated with Admin Panel)
• ✅ Rate Limiting - Redis-based sliding window rate limiting algorithm
• ✅ Health Checks - Multiple health check endpoints
• ✅ Observability - Prometheus metrics, pprof profiling, structured logging

Technical Architecture Upgrades

Core Components:

• HTTP Server - Gin high-performance web framework
• Steem Integration - Steem RPC client for account verification and signature validation
• Storage Abstraction - Unified BlobStore interface with local disk and S3 implementations
• Image Processing - High-performance libvips-based image processing (bimg)
• Cache Layer - Redis for blacklist checking and rate limiting
• Monitoring - Prometheus metrics, pprof profiling, Zap structured logging

🚀 Performance Improvements

Compared to the original Node.js version, the Go rewrite delivers significant performance gains:

Metric	Node.js Version	Go Version	Improvement
CPU Usage	53.5%	25-35%	↓ 35-53%
Memory Usage	662 MB	200-400 MB	↓ 40-70%
Startup Time	Several seconds	< 1 second	↓ >80%
Concurrent Requests	Baseline	2-3x improvement	↑ 100-200%

🔧 Tech Stack

• Language: Go 1.23
• Web Framework: Gin
• Configuration: Viper (supports environment variables, YAML, TOML)
• Logging: Zap (structured JSON logging)
• Redis: go-redis/v9
• Storage: AWS SDK Go v2 (S3), local filesystem
• Image Processing: bimg (libvips bindings)
• Blockchain: steemgosdk, steemutil
• Monitoring: Prometheus, pprof
• Testing: standard library testing, testify

📦 Deployment Features

Flexible Storage Configuration

• Dual Bucket Support - Separate S3 buckets for uploaded and proxied images
• Local Storage - Supports local filesystem storage (dev/test environments)
• S3 Storage - Supports AWS S3 and compatible services (production)
• IAM Roles - Supports EC2 IAM roles for automatic credential retrieval

Containerized Deployment

• Docker Support - Optimized Dockerfile and Docker Compose configuration
• Multi-stage Builds - Reduced image size, improved deployment efficiency
• Health Checks - Container health checks and graceful shutdown

Configuration Management

• Environment Variable Priority - Environment variables override config files
• Multi-environment Configs - Separate configs for default, production, and test environments
• Backward Compatibility - Legacy configuration options preserved for smooth migration

🧪 Test Coverage

The project has established a comprehensive testing framework:

• Unit Tests - Core business logic coverage
• Integration Tests - HTTP handler integration testing
• E2E Tests - End-to-end functionality validation
• Docker Tests - Containerized test environment (no local libvips required)

🔌 API Compatibility

The Go version maintains 100% API compatibility with the Node.js version:

• ✅ All API paths identical
• ✅ Request/response formats unchanged
• ✅ HTTP status codes and error codes match exactly
• ✅ Storage key naming rules fully compatible
• ✅ Can read images stored by Node.js version

API Endpoints

Method	Path	Description
POST	/:username/:signature	Upload image
GET	/:hash	Get image
GET	/p/:base58url	Proxy and transform image
GET	/:width}x:height/:url	Legacy proxy endpoint
GET	/avatar/:username/:size	Get user avatar
GET	/	Health check
GET	/.well-known/healthcheck.json	Health check (JSON)

📚 Project Status

• ✅ Core Features Complete - All major functionality implemented
• ✅ Comprehensive Testing - Unit tests, integration tests, E2E tests
• ✅ CI/CD Ready - GitHub Actions workflows
• ✅ Production Ready - Ready for production deployment

🎯 Next Steps

While core features are complete, we continue to optimize:

1. Performance Optimization - Further reduce resource usage
2. Task Scheduling - Periodic cleanup of unaccessed images
3. Open Source - When the project is stable, we will open source

📞 Contact

Any issues found, feel free to leave a message here.