README.md

The Mule — Go Client Library

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

Usage

package main

import (
    "context"
    "log/slog"
    the_mule "github.com/cryptidtech/the-mule/lib/go"
)

func main() {
    ctx := context.Background()
    client, err := the_mule.NewBuilder().Build(ctx)
    if err != nil {
        panic(err)
    }
    defer client.Close()

    client.SendStatus(ctx, "started")

    for cmd := range client.Commands() {
        slog.Info("received", "command", cmd)
        if cmd == "shutdown" {
            client.SendStatus(ctx, "stopped")
            break
        }
    }
}

Environment Variables

Variable	Required	Description
REDIS_URL	yes	Redis connection URL
PEER_NAME	yes	This peer's name

How it works

• Commands: a goroutine calls BLPOP {peer}_command 0 (truly blocking, no polling) and sends raw strings to a buffered Go channel. Context cancellation is respected — when the context is cancelled or Close() is called, the goroutine exits and the channel is closed. Go's M:N scheduler ensures the blocking goroutine does not block your other goroutines.
• Logs: a slog.Handler captures log records and forwards them to Redis via LPUSH {peer}_log "level|message".
• Status: SendStatus() calls SET {peer}_status <value>, which triggers a keyspace notification on the orchestrator side.

API

• NewBuilder() — reads env vars
• .RedisURL(url) / .PeerName(name) — override
• .Build(ctx) — connect, install slog handler, start command goroutine
• MuleClient.SendStatus(ctx, status) — push status to orchestrator
• MuleClient.Commands() — returns <-chan string yielding commands
• MuleClient.Close() — stop listener and close Redis