RE: [tosca] Proposal for get_property based on discussion in WG on 2019_09_17

[Chris Lauwers <lauwers@ubicity.com>]

Yes, intrinsic functions deserve some more discussion:

 

1. get_operation_output has been deprecated
2. get_artifact returns the path to an artifact so it can be passed to some other artifact (presumable a script). There is likely some value in this. However, we also have the concept of a âprimaryâ artifact and âdependentâ artifacts. Itâs not at all clear to me how these are intended to be used.

 

There are likely other functions that may need to be introduced to make the language more powerful. My understanding is that Heat has a bunch more functions that could be useful in TOSCA.

 

Chris

 

From: Tal Liron <tliron@redhat.com>
Sent: Monday, September 23, 2019 5:47 AM
To: Chris Lauwers <lauwers@ubicity.com>
Cc: Calin Curescu <calin.curescu@ericsson.com>; tosca@lists.oasis-open.org
Subject: Re: [tosca] Proposal for get_property based on discussion in WG on 2019_09_17

 

On Sun, Sep 22, 2019 at 11:09 PM Chris Lauwers <lauwers@ubicity.com> wrote:

-          I donât believe we can do away with SELF unless we also do away with the ability to specify an arbitrary node in the (containing) topology, as in:

 

Good point, but then what about getting properties from groups, policies, etc.? get_property always seemed like a poorly designed function to me. For consistency there should be a way to change your starting point to anything.

-          When discussing your proposal to return sets of values for intrinsic functions, we should start with a discussion about what these functions are intended to be used for.

In a way get_attribute is more interesting, because it involves "live" data.

 

-          There are other âintrinsicâ functions in the current spec for which I donât understand the intended us. Specifically, what would we use âget_nodes_of_typeâ for?

 

What about get_operation_output? And get_artifact? I find a lot of these problematic.