Allow to select used virtualbox image from gitlab-ci.yml file

I am successfully using the gitlab-runner to automate build on a Windows 7 virtualbox image. But unfortunately for different builds I need different Windows images. Right now I can only run one Windows image per gitlab-runner since I can't select the image from the gitlab-ci.yml file. This meas that I e.g. have 5 PCs with 5 different images. This is quite a waste of resources. Especially if I have a build job coming in that e.g. consists of 5 different stages. Due to the image requirements the build of the five stages can't run in parallel on the 5 PCs but one after another on the single PC with the required image while 4 other PCs are idle :-(

Is there a chance that this support is added to the gitlab-runner? Or is someone willing to mentor me so that I can implement it with the chance of the change to get merged upstream?

A solution for you will be to register Runner multiple times from one PC, each time with different image. For example, if you now have such configuration:

PC-1

concurrent = 3

[[runners]]
  name = "PC-1-virtualbox"
  url = "https://gitlab.example.com/"
  token = "token_1_here"
  executor = "virtualbox"
  [runners.ssh]
    user = "user"
    password = "password"
  [runners.virtualbox]
    base_name = "image-1"
    disable_snapshots = false

PC-2

concurrent = 3

[[runners]]
  name = "PC-2-virtualbox"
  url = "https://gitlab.example.com/"
  token = "token_2_here"
  executor = "virtualbox"
  [runners.ssh]
    user = "user"
    password = "password"
  [runners.virtualbox]
    base_name = "image-2"
    disable_snapshots = false

PC-3

concurrent = 3

[[runners]]
  name = "PC-3-virtualbox"
  url = "https://gitlab.example.com/"
  token = "token_3_here"
  executor = "virtualbox"
  [runners.ssh]
    user = "user"
    password = "password"
  [runners.virtualbox]
    base_name = "image-3"
    disable_snapshots = false

You could change this to a configuration file on only one server:

PC-1

concurrent = 3

[[runners]]
  name = "PC-1-virtualbox"
  url = "https://gitlab.example.com/"
  token = "token_1_here"
  executor = "virtualbox"
  [runners.ssh]
    user = "user"
    password = "password"
  [runners.virtualbox]
    base_name = "image-1"
    disable_snapshots = false

[[runners]]
  name = "PC-2-virtualbox"
  url = "https://gitlab.example.com/"
  token = "token_2_here"
  executor = "virtualbox"
  [runners.ssh]
    user = "user"
    password = "password"
  [runners.virtualbox]
    base_name = "image-2"
    disable_snapshots = false

[[runners]]
  name = "PC-3-virtualbox"
  url = "https://gitlab.example.com/"
  token = "token_3_here"
  executor = "virtualbox"
  [runners.ssh]
    user = "user"
    password = "password"
  [runners.virtualbox]
    base_name = "image-3"
    disable_snapshots = false

On the GitLab CE/EE side you still have three Runners and you need to use tags feature from .gitlab-ci.yml file to chose which Runner you want to use, but all jobs are now executed on the one PC.

The problem with VirtualBox executor is that the base virtual machine needs to exist on the Runner's host. It doesn't work like Docker executor, when any image defined in .gitlab-ci.yml can be downloaded from external sources (of course if it's available anywhere). While for Docker executor this is an obvious policy, for VirtualBox it's not and it may confuse users. Having this configured from config.toml this becomes obvious that user need to prepare both - configuration and base image.

However, it would be possible to check if the selected base VM exists on the host, and - if non existing machine is selected from .gitlab-ci.yml definition - print an explicit message to the user (like Virtual Machine 'my_base_machine' not found on Runner's host. Please select an existing base Virtual Machine).

@ayufan, @bikebilly What do you think?

Hey thanks for the tip to define multiple runners on one machine. I wasn't aware that this would work. So maybe this should be stated on the virtualbox help? And yes I think I can live with that. My main pain point was to only have one image per machine which would habe been a waste of resources. And that can be solved with it.

I also understand the problematic of where to get an image from. My dream combination for this would be vagrant and virtualbox. With this I could select an image in gitlab-ci.yml, have the change documented in the source control and run tests on a new image without touching the build machines at all! In my case I would actually use artifactory from jfrog as a vagrant repository.