Arvados

• If Rails.configuration.default_docker_image_for_jobs is false, and docker_image is not set in the job, that should probably be a validation error instead of falling back to the old behavior (running in a non-Docker configuration)
• Instead of runtime_constraints.is_a? Hash suggest setting runtime_constraints ||= {}

I observed that making the job invalid when "no default config + runtime_constraints not including docker image" is a very drastic change. A large number of tests failed without the default config.

This made me wonder if we will have the very undesirable side effect of not being able to access jobs when the system does not have the default config.

I discussed this with Peter, and we decided to not do this as part of this update (the feature does not ask for it).

If we want this, we will address it in a different feature request.