Rocket.Chat Fails Due to TCP Broker Port Conflict (`EADDRINUSE` on :::XXXXX) - FIXED

🛠️ Rocket.Chat Fails Due to TCP Broker Port Conflict (EADDRINUSE on :::41403) — FIXED

❗ The Problem

After restoring a Rocket.Chat instance via mongorestore (including rocketchat_apps collection), and running it behind Docker + Traefik, the platform appeared to start fine, but the logs were filled with:

ERROR .../TRANSPORTER: Server error. Error: listen EADDRINUSE: address already in use :::41403

This caused:

• App Engine Deno subprocesses to fail.
• Rocket.Chat UI to partially load (but no app could be loaded).
• Broker reconnection attempts every 5 seconds.
• No listening process actually bound to port 41403 inside the container.

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🧪 What Was Tried (and Failed)

• Setting sysctl net.ipv6.conf.all.disable_ipv6=1 inside the container.
• Verifying exposed ports using ss, netstat, etc. — no explicit conflict.
• Explicitly setting BROKER_TRANSPORTER and ROCKETCHAT_APPS_ENGINE_BROKER_TRANSPORTER to different loopback addresses/ports.
• No known issue from Traefik side (proxy working perfectly).

Nothing helped.

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✅ The Actual Root Cause & Fix

Turns out the issue was that two Rocket.Chat apps were already marked as manually_enabled in the DB, and both attempted to spin up their own Moleculer broker, causing an internal port collision on ::41403.

💥 Fix (run inside Mongo shell):

use rocketchat
db.rocketchat_apps.updateMany({}, { $set: { status: 'disabled' } })

🌀 After restarting the container, the broker booted cleanly, no more EADDRINUSE, and apps could be re-enabled one by one via the UI or DB.

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🧰 Config Reference (doesn’t help alone!)

⚠️ These env vars alone didn’t solve anything unless the DB apps were disabled.

rocketchat:
  image: rocketchat/rocket.chat:latest
  environment:
    BROKER_TRANSPORTER: tcp://0.0.0.0:42000
    ROCKETCHAT_APPS_ENGINE_BROKER_TRANSPORTER: tcp://127.0.0.1:42000
  sysctls:
    - net.ipv6.conf.all.disable_ipv6=1

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💡 Suggestions

• Rocket.Chat should check for multiple apps trying to bind the same broker port.

• Perhaps include a startup flag like:

  DISABLE_ALL_APPS_ON_BOOT=true
  

  …to prevent these port conflicts after database restores or migrations.

• At the very least, if EADDRINUSE is detected, auto-disable the crashing app with an informative log.

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💬 Hope this helps someone who is restoring or migrating Rocket.Chat and hitting this obscure bug.

Let me know if logs or further context are useful!

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No repository files, tests, or entry points are named. Start with the Mongo shell and the rocketchat_apps collection described in the issue, then inspect the Docker container logs after a restore; done would mean restarting without EADDRINUSE and allowing apps to load.