Adding a default provider [discussion]

[cdrage]

Please read: https://github.com/projectatomic/atomicapp/issues/378

We would like to propose adding:

specversion: 0.0.2
id: guestbook-app

config:
  defaultprovider: docker
...

To the spec, giving an implementation control on what to deploy by default if multiple providers are provided.

[goern]

I would consider this an experimental extension: add it to the Nulecule files you use with current version of atomicapp and simply use it. For the Nulecule Spec's point of view, I think we dont need the semantic of a 'default provider'. If it turns out to be useful, lets move it from 'experimental' to be included in the Nulecule spec itself.

[aweiteka]

As an experimental extension I suggest it goes into the metadata section so it's still valid:

metadata:
  name: Hello Apache App
  appversion: 0.0.1
  description: Atomic app for deploying a really basic Apache HTTP server
  defaultprovider: docker
...

[vpavlin]

As noted in https://github.com/projectatomic/atomicapp/issues/378#issuecomment-159614337 - we don't need any changes in spec or implementation specific to the default provider if we allow/start using global params

[rtnpro]

we don't need to add another key, as in

defaultprovider: docker

We just need to update Nulecule spec to support params in the root level, to incorporate params in general section in the Nulecule spec file.

atomicapp already supports params at the root level in a Nulecule file.

[goern]

You should be able to do that without any restrictions, its just a YAML file :) As I said this is an experimental extension of the Nulecule Specification Atomic App introduced, lets see how it works out.

Lets see in mid Jan how it evolved and if we need to update ethe spec.

[goern]

@rtnpro I think this could be closed, as I merged the global params PR