Digital Ocean image_id periodically changes, reference "slug" instead
On Digital Ocean, they appear to periodically update images, and with that a new image_id. This means that if you setup an image in TheForeman, then come back a few weeks later, you may get an error when attempting to create a new host with that image. The workaround is that the image ID needs updated in the foreman "image" definition. The workaround suggested by Digital Ocean support was to reference the "slug" provided by the API. This is not currently exposed via Fog, so that will require some Fog changes as well.
Once Fog::Compute::DigitalOcean exposes the slugs, we will need to modify the image selection process to ensure it stores the "slug" instead of the numeric "id"