Re: [netmod] Action and RPC statements

Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de> Tue, 31 October 2017 15:20 UTC

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Date: Tue, 31 Oct 2017 16:14:15 +0100
From: Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de>
To: Robert Wilton <rwilton@cisco.com>
Cc: Martin Bjorklund <mbj@tail-f.com>, andy@yumaworks.com, netmod@ietf.org, Randy Presuhn <randy_presuhn@alumni.stanford.edu>
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Subject: Re: [netmod] Action and RPC statements
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On Tue, Oct 31, 2017 at 02:14:20PM +0000, Robert Wilton wrote:

> Is <operational> always the right datastore to evaluate RPC input/output
> data relative to?  For most RPCs this seems to be the right choice by
> default but it also seems plausible that someone may wish to define an RPC
> that wants to validate its input parameters against the contents of another
> datastore.

Yes.
 
> An example could be an "is-applied" RPC that takes a path to a subtree in
> <running> or <intended> and checks whether the configuration for that
> subtree is fully represented in <operational>.

How is this different from say partial locks (RFC 5717)? Note that in
your example, you carry an xpath value as part of the RPC invocation
to the server and the RPC code on the server then is interpreting the
xpath value; this is not the same has having an xpath expression in
the definition of the RPC itself (e.g., as part of a constraint).

I believe we previously concluded that xpath expressions that are part
of the schema definition of an RPC / action are evaluated against
<operational>. I think this is a reasonable interpretation and we
can't affort a vaguely defined xpath context here.

/js

-- 
Juergen Schoenwaelder           Jacobs University Bremen gGmbH
Phone: +49 421 200 3587         Campus Ring 1 | 28759 Bremen | Germany
Fax:   +49 421 200 3103         <http://www.jacobs-university.de/>