vagrant-docker-provider

This repo will build a docker image that can be used as a provider for Vagrant as a Linux development environment.

The ready made Docker Hub image can be found here: rofrano/vagrant-provider:ubuntu

Why Vagrant with Docker?

This was inspired by Apple's introduction of the M1 chip which is ARM based. That means that solutions which use Vagrant and VirtualBox will not work on Apple M1 because VirtualBox requires an Intel processors. This lead me to find a solution for a virtual development environment that works with ARM and thus Apple M1 computers.

Docker has introduced the Apple M1 Tech Preview that runs Docker on Macs that have the Apple M1 chip. By using Docker as a provisioner for Vagrant, we can simulate the same experience as developers using Vagrant with VirtualBox. This is one case where you actually do want a Docker container to behave like a VM.

Image Contents

This image is based on Ubuntu Focal 20.04 and contains the packages that are needed for a valid vagrant box. This includes the vagrant userid with password-less sudo privileges. It also contains as sshd server. Normally, it is considered a bad idea to run an ssh daemon in a Docker container but in this case, the Docker container is emulating a Virtual Machine (VM) to provide a development environment so it makes perfect sense. ;-)

Example Vagrantfile

Here is a sample Vagrantfile that uses this image:

Vagrant.configure("2") do |config|
  config.vm.hostname = "ubuntu"

  config.vm.provider :docker do |docker, override|
    override.vm.box = nil
    docker.image = "rofrano/vagrant-provider:ubuntu"
    docker.remains_running = true
    docker.has_ssh = true
    docker.privileged = true
    docker.create_args = ["-v", "/sys/fs/cgroup:/sys/fs/cgroup:ro"]
  end  
end

If you want to test the ARM version on an Intel computer just add --platform=linux/arm64 to the docker.create_args line. This will add the --platform flag to the docker run command to force the aarch64 image to be used via qemu.

Command Line Usage

To use this provider, add the --provider flag to your vagrant command:

vagrant up --provider=docker

This will use this the docker image specified in your Vagrantfile as the base box.

Build Multi-Archtecture Image

To build this image you must use buildx and build it for multiple architectures so that it can run on both Intel and ARM machines.

If you don't have a builder you must first create one:

% export DOCKER_BUILDKIT=1
% docker buildx create --use --name=qemu
qemu
% docker buildx inspect --bootstrap

Then you can build the multi-platform image like this:

docker buildx build --tag rofrano/vagrant-provider:ubuntu --platform=linux/amd64,linux/arm64 --push .

This will use QEMU to build a multi-platform image and push it to docker hub.

Credits

A huge thanks to Matthew Warman who provided the Dockerfile from mcwarman/vagrant-provider as the bases for my Dockerfile using systemd. He added all the magic to make it work and I am very greateful for his generosity.