Add support for stateless actions

[simonferquel]

This implements stateless actions as defined in cnabio/cnab-spec#85.

[radu-matei]

Ok, this is in more advanced state than https://github.com/radu-matei/duffle/tree/feat-629-sync-action-spec, so I'll close that one.

Just for future reference, let's make sure we assign an issue before starting the work on it, so we don't duplicate work 😃

[simonferquel]

Sorry about the duplicated work. Fixed the annotations and added a notStateless const for more clarity

[radu-matei]

This looks good, although I have a question (that I think will result in an issue for Duffle) - according to the spec for stateless actions: The action does not act on a claim - however, duffle run requires an installation name, and does not accept a bundle.

If I understand the usage of stateless actions correctly, the above would be something we want to support, right?

[simonferquel]

Yes, I only focused on the lower level things for now (as my honest goal was to remove a hack we have in docker-app which already defines implicitly stateless actions). I have no idea how the duffle UX should be for such action though. Docker-app is easier as it is an opinionated tool and we have top level commands like `docker app inspect/render` for them.

…

________________________________ From: Radu M <[email protected]> Sent: Tuesday, February 12, 2019 2:46:56 PM To: deislabs/duffle Cc: Simon Ferquel; Author Subject: Re: [deislabs/duffle] Add support for stateless actions (#630) This looks good, although I have a question (that I think will result in an issue for Duffle) - according to the spec for stateless actions: The action does not act on a claim - however, duffle run requires an installation name, and does not accept a bundle. If I understand the usage of stateless actions correctly, the above would be something we want to support, right? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub<#630 (comment)>, or mute the thread<https://github.com/notifications/unsubscribe-auth/ABmYFRK48yO7RxLYJGzlb2nMnPzd14S3ks5vMsXQgaJpZM4a2NLz>.

[simonferquel]

Hmm, also, we must also be able to pass parameter values for such stateless actions like we do with docker app render -p nginx.scale=3. Definitely a tricky UX problem.

[radu-matei]

Yeah, that totally makes sense, and I'll create a new issue to track this.

Could you please, also sign your commits?
Otherwise, this LGTM.

[simonferquel]

They are signed with git commit -s. Do you require a PGP signature ?

[radu-matei]

Yeah, we haven't enforced this yet, but as it's best practice, I think we should start to.

[radu-matei]

LGTM.

Let's keep the conversation about Duffle CLI support in #629.

Thanks for your contribution!

[radu-matei]

Oh, there's a small conflict on this - once it's resolved, I think we can go ahead and merge this, keeping the discussion about the UX issue in #629.

Thanks!

[simonferquel]

Oops, sorry, totally forgot about this one. Rebasing right now

[simonferquel]

Now rebased, PTAL @radu-matei