docker-dns

dns container for custom aliases

Problem

• You maintain a lot of domains, steadily growing.
• Your docker-compose.yaml already has way too many aliases for your LB.
• You want to update the dns list automatically without patching the compose file.

Solution

• Write a DNS Server that sits in your compose environment, and enables you to define mappings from domain alias to container name.

This is what this experiment was about. And it worked.

Configuration

Since it's an experiment there is not much config options.

Define the aliases in dnsserver/data/alias

The rest should be obvious from docker-compose.yaml or the go code.

Restrictions

Restrictions for the docker-compose setup:

• you need to attach your docker services via IP address to this DNS Service
• so you need to define a docker network

Tests

Since this project was a just a quick try, there are no unit tests yet. But to hold the code stable there is at least a functional test.

• functional tests

Go simply rocks

It was fun to implement using go and those nice libraries:

DNS: htts://github.com/miekg/dns

Docker: https://github.com/docker/docker