README.md

The Mule — Rust Client Library

Rust client library for peer applications running under The Mule test orchestrator.

Usage

use tokio_stream::StreamExt;

#[tokio::main]
async fn main() {
    let mut client = the_mule::MuleClientBuilder::new()
        .build()
        .await
        .expect("failed to build client");

    client.send_status("started").await.unwrap();

    loop {
        let cmd = {
            use std::pin::Pin;
            let mut pinned = Pin::new(&mut client);
            pinned.next().await
        };
        match cmd {
            Some(the_mule::Command::Shutdown) => {
                client.send_status("stopped").await.ok();
                break;
            }
            Some(cmd) => tracing::info!("received: {:?}", cmd),
            None => break,
        }
    }
}

Environment Variables

Variable	Required	Description
REDIS_URL	yes	Redis connection URL
PEER_NAME	yes	This peer's name
RUST_LOG	no	tracing filter (e.g., info)

How it works

• Commands: a background tokio task calls BLPOP {peer}_command 0 (truly blocking, no polling) and sends parsed Command values through an mpsc channel. Your code consumes them via the Stream trait.
• Logs: a tracing subscriber layer captures log events and forwards them to Redis via LPUSH {peer}_log "level|message" in a background task.
• Status: send_status() calls SET {peer}_status <value>, which triggers a keyspace notification on the orchestrator side.

API

• MuleClientBuilder::new() — reads env vars
• .redis_url(url) / .peer_name(name) — override
• .build().await — connect, install tracing, start background tasks
• MuleClient::send_status(status) — push status to orchestrator
• impl Stream<Item = Command> — yields parsed commands
• Command enum: Connect, Disconnect, Shutdown, Restart, Peer, Test