Docker DNS

Docker DNS is a DNS server that resolve Docker's container name into A, AAAA or PTR records to retrieve IPv4, IPv6 associated to a container name or the container associated to an IP address.

Installation configuration and execution

First you need to clone this repository

git clone https://github.com/dangoncalves/docker-dns

Then change directory and install dependencies

cd docker-dns
poetry install

Execute the script as root (to bind on port 53)

python3 docker-dns.py

Finally you can edit /etc/resolv.conf and put that line at the file's begining (don't remove other nameserver entries)

nameserver 127.0.0.1

Options

There are three options you can use to customize execution:

• --port customize the port docker-dns will listen on (default 53)
• --listen-address customize the address docker-dns will listen on (default 127.0.0.1)
• --forwarders dns forwarders' list (coma separated list)

Tests

poetry shell
make prepare-test
make test

License

This project is under WTFPL

TODO - Roadmap

The project's goal is just to resolve docker containers' name into IP address. This first version do the job, but there are still some things to do like:

• add a Dockerfile to start the server Not relevant
• add tests
• add networks support
• add AAAA queries support
• add PTR queries support
• add SRV queries support Not relevant
• add HEALTH CHECK support (do not resolve a container that is not healthy)
• automate installation
• improve documentation
• add Windows and Mac OS support (tested only on Linux for now)