Run specs through docker image

[solsson]

Two benefits if Testbeat can run from docker image:

• No need for gem install this and that
• Can test a dockerized service using a link

Will it also be able to test a service by name in the host's hosts file? If so there's not many drawbacks.

Specs can be for example /spec/*_spec.rb by default, overridable with env. /spec can be COPY'd to in a downstream Dockerfile, or simply mounted as volume.

NODE is no longer a good name, and maybe never was, for the System Under Test. In contexts of Docker or Kubernetes it is rather a Service. We can keep the NODE env for backwards compatibility but use something else to name the link. svc or service or sut or target

[solsson]

Docker scenarios tend to involve multiple services on different hostnames; a poor fit for the NODE concept in testbeat that sort of assumes that tests and assertions target the same VM.

For a docker concept to be worthwhile we might have to add a host/service argument in the spec syntax, in describes.

[takesson]

I would like to avoid that. Suggest combination of:

• Tests apply to a single service (which might have back-end containers). No problem.
• Tests apply to a whole system which is accessed through a single proxy. No problem.

Testing multiple different services can be done in separate test runs?