infinite-git/plan.md

Infinite Git HTTP Server Implementation Plan

Overview

I'll implement a Go HTTP server that generates a new commit every time a client pulls from the repository. This creates an "infinite" Git repository where the main branch is updated with a new commit on each fetch operation.

Key Components

1. HTTP Endpoints

• GET /info/refs?service=git-upload-pack - Reference discovery (triggers commit generation)
• POST /git-upload-pack - Handle fetch/clone with dynamically generated commits
• Reject all push operations with 403 Forbidden

2. Core Modules

• pktline package - Handle Git's packet line format
• server package - HTTP server and routing
• generator package - Generate new commits on demand
• upload package - Modified git-upload-pack to serve dynamic content
• repo package - Git repository management

3. Commit Generation Strategy

• On each pull request, generate a new commit with:
  • Timestamp in commit message
  • Unique content (e.g., pull counter, random data, or timestamp)
  • Parent pointing to previous HEAD of main
• Update main branch to point to new commit
• Use Git plumbing commands or go-git library for commit creation

4. Project Structure

.
├── cmd/
│   └── infinite-git/
│       └── main.go          # Entry point
├── internal/
│   ├── pktline/
│   │   ├── reader.go        # Pkt-line reader
│   │   └── writer.go        # Pkt-line writer
│   ├── server/
│   │   ├── server.go        # HTTP server
│   │   └── handlers.go      # HTTP handlers
│   ├── generator/
│   │   └── commit.go        # Commit generation logic
│   ├── upload/
│   │   └── pack.go          # Modified git-upload-pack
│   └── repo/
│       └── repo.go          # Repository management
├── go.mod
└── README.md

5. Implementation Details

• Initialize a bare Git repository on server startup
• Intercept ref discovery requests to generate new commits
• Use mutex to handle concurrent pull requests safely
• Generate commits using either:
  • git hash-object, git update-index, git write-tree, git commit-tree
  • Or go-git library for pure Go implementation
• Each commit could contain:
  • A file with incrementing counter
  • Timestamp of the pull request
  • Client information (if available)

6. Features

• Thread-safe commit generation
• Persistent Git repository on disk
• Configurable commit content generation
• Rate limiting (optional)
• Logging of all pull operations
• Environment variable configuration

Example Behavior

# First client pull
$ git pull origin main
# Gets commit 1a2b3c4... "Pull #1 at 2024-01-20 10:00:00"

# Second client pull (moments later)
$ git pull origin main  
# Gets commit 5d6e7f8... "Pull #2 at 2024-01-20 10:00:05"