jlxip / zodiac

A reverse proxy and load balancer for Gemini

zodiac

Introduction

Zodiac is a low-footprint high-performance reverse proxy and load balancer for Gemini, written in C++. Think of it like an nginx for Gemini, meant to connect to FastCGI-like local servers, or backends.

This project:

• Soothes the Gemini backend creation, since they don't need to worry about:
  • TLS
  • Timeouts
  • CRLF, meaning that it's guaranteed to be there
• Performs demultiplexing of requests via SNI.
• Returns status code 43 (PROXY ERROR) in case the backend doesn't answer.
• Can handle many simultaneous connections with very little resources.

Configuration file

The configuration file defaults to ./zodiac.conf, but a different one can be specified via the ZODIAC_CONFIG environment variable.

An example config is given in the example.conf file at the root of the repository.

FastCGI-like protocol

The backend receives <URL><CR><LF><Client's IP><CR><LF>. This way, the proxy is transparent while the specification is not broken, since the second line can be ignored.

Docker

A Dockerfile is available at the root of this repository. It is automatically built and pushed to the Docker Hub on each release, with the name jlxip/zodiac. To use it, run something along the lines of:

docker volume create zodiac_config
sudo cp yourconfig.conf /var/lib/docker/volumes/zodiac_config/_data/zodiac.conf
docker run -d -p 1965:1965 --name myserver --restart=unless-stopped -v zodiac_config:/config jlxip/zodiac:latest

Additional information

• The first version was written in 4 hours, one hour after knowing Gemini exists.
• Zodiac follows Semantic Versioning 2.0.0.
• Dependencies: openssl, iniparser, and ssockets.

Backends for zodiac

• bsgemini, by me, for static servers, written in C++.

Things to do before 1.0.0

• Timeouts
• Multiple capsules
• Worker threads
• More config (listening IP, port, timeouts)
• RR load balancing
• Config file in other place ($ZODIAC_CONFIG)
• Move to epoll
• CI/CD
• Docker image