Lure

A modern Minecraft native proxy and load balancer built with Rust

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Overview

Lure is a sophisticated, but lightweight enough, high-performance proxy for Minecraft. It reach high performance with

• Fair tokio socket polling (kinda fast ngl)
• Toasty io-uring, not even haproxy done this already
• Unrailed safety prooven with hundred of hours of hardcore Forge connection, while handling few dozen player Minecraft network

Philosophy

Multi-tenancy design model, that to using well serialized configuration not config-generation and reloading (which prone gimmick at scale)

Gate(lite), which is a mature proxy for this purpose, but I wasn't able to make it work on this model.

Features

• Provision with an API backend for orchestration (via RPC, see Elysia implementation)
• Multi-server & multi-host support
• Proxy Protocol (supported Paper-derived, Velocity and Bungeecord)
• Highly observable system through OTEL
• Global threat control (WIP), with socket ratelimit, etc.
• Proxy-Protocol authentication (not even tcpshield doing this atm, but uhh we don't kinda need this are we?)

Cutting edge

Future proof features, with considerations that some "unsafe" are fine. Project is using rustfmt nightly. To extends features like runtime monitoring (I have some jealousy with go that they have actually mature otlp).

Updates

The shortest road

With io-uring (test environment), up to 16% CPU instructions, and noticibly latency is reduced by 1μs 🥳. This cannot be made efficient in real time, but we can accelerate it!

The coldest process

Optional mimalloc crate feature allocator reduces CPU usage (4% → 1%) at the cost of higher memory usage (~47MiB vs ~20MiB).

Compatibility

• Guaranteed to work with 1.7+
• Since HaProxyProtocol plaintext is not very common, only v2 is supported, most immplemented.
• FML (Forge) Handshake support is added

Quirks

• TL*uncher Guard seemingly causing trouble
• Watch for any back-connect plugin like Geyser if proxy protocol is enabled. You have to enable both proxy_protocol key from desired plugin/paper config + geyser config
• 0.1.2 -> 0.1.3 has major config layout changes

Configuration

The server can now be configured stand-alone without the need of RPC backend

# settings.toml
inst = "main"
bind = "0.0.0.0:25577"
proxy_procol = false
# key name to be changed
max_conn = 65535
cooldown = 3 
# ---

[strings]
# vendor specific, all keys optional
MESSAGE_CANNOT_CONNECT = "Cannot connect to destinated server:"
ERROR = "Error"
SERVER_OFFLINE = "Server is offline :("
ROUTE_NOT_FOUND = "The destinated server is not registered"
SERVER_LIST_BRAND = "oops"

[[route]]
matchers = ["mc.acme.co", "play.acme.co"]
preserve_host = true # false by default
proxy_protocol = true # false by default
endpoints = ["craft-clust-1001.acme.co:25565", "craft-clust-1002.acme.co:25565"]

[[route]]
matcher = "eu.acme.co"
preserve_host = false
proxy_protocol = true
endpoint = "craft-clust-1001.acme.co:25565"

To configure RPC url, use LURE_RPC env

Credits

Original implementor sammwyy