technitium-companion: Automatic DNS record management for Docker/Traefik

[maxfield-allison]

Hi everyone,

I wanted to share a tool I built that integrates with Technitium DNS Server for automatic DNS record management in Docker environments.

What is it?

technitium-companion is a lightweight Go application that watches Docker events and automatically creates/deletes DNS A records in Technitium based on Traefik router labels.

Why I built it

I run a Docker Swarm cluster with Traefik as my reverse proxy, and I was manually creating DNS records in Technitium every time I deployed a new service. Since Traefik labels already define the hostnames, I wanted to automate the DNS side.

How it works

1. You deploy a container with a Traefik label:

   labels:
     - "traefik.http.routers.myapp.rule=Host(`myapp.example.com`)"

2. technitium-companion detects this and calls the Technitium API to create an A record

3. When the container stops, the record is automatically deleted

Features

• Docker & Swarm support: Works with standalone Docker and Docker Swarm clusters
• Label parsing: Handles complex Traefik rules including Host() || Host() for multiple domains
• Selective management: Include/exclude regex patterns to control which hostnames are managed
• Startup reconciliation: Full sync on startup ensures consistency
• Observability: Prometheus metrics endpoint, structured JSON logging
• Security: Supports Docker socket proxies, Docker secrets for API tokens

Links

• GitHub: https://github.com/maxfield-allison/technitium-companion
• Docker Image: ghcr.io/maxfield-allison/technitium-companion:latest

Technical notes

• Uses the Technitium HTTP API (/api/zones/records/add, /api/zones/records/delete)
• Written in Go, multi-arch images for amd64 and arm64
• MIT licensed

I'd love to hear feedback from other Technitium users. Are there features that would make this more useful for your setup?

Thanks to @ShreyasZare and other contributors for building such an awesome DNS server!

[ShreyasZare]

Thanks for sharing it here. I would recommend that you share this on reddit.com/r/technitium too so that it reaches more people in the community.

[maxfield-allison]

I had planned to! I've had to create a new professional-side reddit account attached to my actual name so I'm currently getting the karma up.

[maxfield-allison]

As soon as I shared and went back to the main page I see that a month ago someone built an app with a different purpose but essentially the same name... love that. Might need to rebrand lol