Tricking kitchen-vagrant to use the vagrant/docker provider (why? for better caching via vagrant-cachier)

.kitchen.docker.yml

---
driver:
  name: docker

driver_config:
  provision_command:
    - curl -L https://www.opscode.com/chef/install.sh | bash -s -- -v 12.3.0
    - env GEM_HOME=/tmp/verifier/gems GEM_PATH=/tmp/verifier/gems GEM_CACHE=/tmp/verifier/gems/cache /opt/chef/embedded/bin/gem install thor busser busser-serverspec serverspec bundler && chown -R kitchen:kitchen /tmp/verifier
  require_chef_omnibus: false
  use_sudo: false

.kitchen.yml

---
driver:
  name: vagrant

provisioner:
  name: chef_zero
  require_chef_omnibus: 12.3.0
  chef_omnibus_install_options: -d /tmp/vagrant-cache/vagrant_omnibus

platforms:
  - name: ubuntu-14.04

suites:
  - name: default
    run_list:
      - recipe[foo::default]

README.md

README

This shows how to use the exact same .kitchen.yml for both Vagrant/VirtualBox and Vagrant/Docker when using the kitchen-vagrant driver.

Why not plain Docker?

Why not simply using plain Docker with the kitchen-docker driver?

Well, there is a subtle difference: while plain kitchen-docker is more lightweight and starts up faster, kitchen-vagrant can cache downloaded files via vagrant-cachier, which can save you lots of traffic and idle time during the kitchenci run.

Using kitchen-vagrant with Vagrant/VirtualBox

This is pretty straightforward. VirtualBox is already the default provider, so you just run kitchenci:

$ kitchen test

Using kitchen-vagrant with Vagrant/Docker

This requires some trickery to make it work transparently without changing the .kitchen.yml:

1. you need to provide a docker basebox that works via config.vm.box in the Vagrantfile
2. you need to add this basebox under the "opscode-ubuntu-14.04" name / for the docker provider

So let's do the trickery first:

$ vagrant box add opscode-ubuntu-14.04 https://atlas.hashicorp.com/tknerr/boxes/baseimage-ubuntu-14.04/versions/1.0.0/providers/docker.box --provider=docker

Then we can simply set the VAGRANT_DEFAULT_PROVIDER to docker and run kitchenci:

$ set VAGRANT_DEFAULT_PROVIDER=docker
$ kitchen test

Using kitchen-docker with plain Docker

For the sake of completeness, lets show the plain kitchen-docker variant too. This uses a separate .kitchen.docker.yml file to override the vagrant driver with the docker driver (including some optimizations to cache the omnibus installer and verifier gems in a docker layer).

So you have to set the KITCHEN_LOCAL_YAML accordingly before running kitchenci:

$ set KITCHEN_LOCAL_YAML=.kitchen.docker.yml
$ kitchen test