Docker DNS

Docker DNS creates a container that works as a DNS for docker containers in you machine. Every running container will be accessible by $container_name.docker for example. You could inform you own domain if you like. Your domains are available inside and outside docker, but just for you machine. For example, you could access http://nginx.docker from your browser window OR from inside a container.

It was created to allow you to work in a container as if was a "real" server setup. You will have access to all ports/services inside the container without need to expose all the ports. You can publish ports as well to access it like the old way. E.g.: 127.0.0.1:8080 -> container_ip:80

It was tested on linux and macOS sierra. macOS environment has a downside that you will always run the make tunnel every time you boot the host machine,

The main usage is for development environment only, should not be used in production environment.

By default it will enable create that hosts: ns0.docker and ns0.$YOUR_HOSTNAME.docker.

Supported commands

make install - Set up all environment;
make uninstall - Remove configuration files from your system;
make show-domain - Show the working domain of your installation;
make tunnel - Create a tunnel to route all traffic to you docker containers. Available only in macOS, on linux you don't need that feature.

Options

In make install you can pass some variables to change how setup is done. You can change the working domain for example.

tld: working domain. It can be any domain name but the domains designed to work in loopback network. For example yourmachine.dev will create names like CONTAINER_NAME.yourmachine.dev. You can have docker.your_real_domain.com as well so it will create names like CONTAINER_NAME.docker.your_real_domain.com . Default value: docker`;
tag: Tag name for the created docker image. It should be changed only if you have a name conflict Default value: ns0
name: Running container name. Default value: the tag name

Example: make install tld=docker.dev tag=dns Will create a docker image name dns and it will be available as dns.docker.dev so you could run dig www.google.com @dns.docker.dev

Requirements

Docker CE or Docker for mac
Homebrew for macOS machines

Tested enviroment

Docker 17.0.4.0-ce
Docker for mac 17.06.0-ce, 17.09.1-ce-mac42
Ubuntu: 16.04, 17.04, 17.10, 18.04
Fedora: 27
macOS: Sierra, High Sierra

Troubleshooting

If you are using macOS, on restart, you will loose access to your containers. You need to recreate a tunnel to route all traffic to docker network through it on every boot. Just execute sudo make tunnel from docker-dns folder

License

MIT

Thanks

Thanks to https://github.com/apenwarr/sshuttle for the great poor's man VPN service! An easy way to setup tunneling on macOS

yagotome / docker-dns