Geser

Geser is a Gemini protocol server written in Rust. This project serves Markdown pages and static assets (such as images) from a designated folder, converting Markdown content into Gemini-compliant text. This is my very first Rust project, and it showcases Rust’s asynchronous I/O, TLS support with hot reloading, and a modular code structure.

Features

• Gemini Protocol Server
  Implements the Gemini protocol to securely serve content over TLS.

• Markdown to Gemini Conversion
  Converts Markdown pages into Gemini format using pulldown-cmark. Headings, paragraphs, links, images, and inline code are processed and transformed into a Gemini-friendly text output.

• Static File Serving
  Serves static assets (e.g., images) stored in a designated folder.

• TLS Support with Hot Reload
  Uses TLS for secure communication and includes a background task for periodic certificate reloading.

• Asynchronous I/O
  Built on Tokio for non-blocking, high-performance asynchronous operations.

• Caching
  Implements in-memory caching (using DashMap) to reduce disk I/O for frequently accessed content.

• Modular Structure
  The code is organized into multiple modules (config, server, tls, pages, cache, util) to improve maintainability and scalability.

Getting Started

Prerequisites

• Rust (latest stable version)
• Cargo
• OpenSSL (for generating certificates)

Installation

Clone the repository:

git clone https://github.com/iaaaannn0/Geser.git
cd Geser
# Generate a self-signed certificate for testing (make sure your OpenSSL version supports -addext):
openssl req -x509 -nodes -newkey rsa:4096 -keyout key.pem -out cert.pem -days 365 -subj "/CN=localhost" -addext "subjectAltName = IP:127.0.0.1"

Configuration

The project uses a configuration file (config.toml) to set parameters such as the listening address, certificate paths, pages directory, and TLS reload interval. An example config.toml is provided:

address = "0.0.0.0:1965"
cert_path = "cert.pem"
key_path = "key.pem"
pages_dir = "pages"
tls_reload_interval_secs = 300

You can also override these settings using environment variables with the GEMINI_ prefix.

Running the Server

Build and run the project in release mode:

cargo run --release

The server will start and listen on the address specified in your configuration file.

Testing

Use a Gemini client, such as Lagrange or Amfora, to test the server:

gemini://127.0.0.1:1965

Project Structure

Geser/
├── Cargo.toml
├── config.toml         # Configuration file
├── pages/              # Directory for Markdown pages and static assets
│   ├── index.md
│   └── images/
│       └── example.jpg
└── src/
    ├── main.rs         # Entry point
    ├── config.rs       # Configuration management
    ├── server.rs       # Server and connection handling
    ├── tls.rs          # TLS configuration and hot reload
    ├── pages.rs        # Markdown and static file serving
    ├── cache.rs        # In-memory caching
    └── util.rs         # Utility functions (e.g., path sanitization)

About

Geser is my very first Rust project. I created it as an experiment to learn Rust's capabilities in asynchronous programming, secure network communication, and modular software design. so any feedback, bug reports, or contributions are welcome.

Contributing

Contributions are welcome! If you have ideas or improvements, please open an issue or submit a pull request on GitHub. For major changes, it’s best to open an issue first to discuss what you’d like to change.

License

This project is licensed under the MIT License.