Re: [netmod] import-by-semver issue
Martin Bjorklund <mbj@tail-f.com> Sun, 24 March 2019 15:21 UTC
Return-Path: <mbj@tail-f.com>
X-Original-To: netmod@ietfa.amsl.com
Delivered-To: netmod@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id AA52C1279B3 for <netmod@ietfa.amsl.com>; Sun, 24 Mar 2019 08:21:41 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.9
X-Spam-Level:
X-Spam-Status: No, score=-1.9 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id KuovIrqvwg6l for <netmod@ietfa.amsl.com>; Sun, 24 Mar 2019 08:21:39 -0700 (PDT)
Received: from mail.tail-f.com (mail.tail-f.com [46.21.102.45]) by ietfa.amsl.com (Postfix) with ESMTP id 41DED12787E for <netmod@ietf.org>; Sun, 24 Mar 2019 08:21:39 -0700 (PDT)
Received: from localhost (dhcp-9104.meeting.ietf.org [31.133.145.4]) by mail.tail-f.com (Postfix) with ESMTPSA id D49831AE034E; Sun, 24 Mar 2019 16:21:36 +0100 (CET)
Date: Sun, 24 Mar 2019 16:21:30 +0100
Message-Id: <20190324.162130.857835975235711028.mbj@tail-f.com>
To: rwilton@cisco.com
Cc: j.schoenwaelder@jacobs-university.de, netmod@ietf.org
From: Martin Bjorklund <mbj@tail-f.com>
In-Reply-To: <de771cdd329046cfa42a92d8d8ecf525@XCH-RCD-007.cisco.com>
References: <4c0a8dca338f4ca384dea933f046511e@XCH-RCD-007.cisco.com> <20190324143116.evgabiqpmz5gwgem@anna.jacobs.jacobs-university.de> <de771cdd329046cfa42a92d8d8ecf525@XCH-RCD-007.cisco.com>
X-Mailer: Mew version 6.7 on Emacs 24.5 / Mule 6.0 (HANACHIRUSATO)
Mime-Version: 1.0
Content-Type: Text/Plain; charset="utf-8"
Content-Transfer-Encoding: base64
Archived-At: <https://mailarchive.ietf.org/arch/msg/netmod/PS10A3XFHVbpBJXOuNeY4_5PskY>
Subject: Re: [netmod] import-by-semver issue
X-BeenThere: netmod@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: NETMOD WG list <netmod.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/netmod>, <mailto:netmod-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/netmod/>
List-Post: <mailto:netmod@ietf.org>
List-Help: <mailto:netmod-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/netmod>, <mailto:netmod-request@ietf.org?subject=subscribe>
X-List-Received-Date: Sun, 24 Mar 2019 15:21:42 -0000
"Rob Wilton (rwilton)" <rwilton@cisco.com> wrote: > Hi Juergen, > > > -----Original Message----- > > From: Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de> > > Sent: 24 March 2019 15:31 > > To: Rob Wilton (rwilton) <rwilton@cisco.com> > > Cc: Andy Bierman <andy@yumaworks.com>; NetMod WG <netmod@ietf.org> > > Subject: Re: [netmod] import-by-semver issue > > > > On Sun, Mar 24, 2019 at 02:07:15PM +0000, Rob Wilton (rwilton) wrote: > > > Hi Andy, > > > > > > There are many ways to write and design compilers. > > > > > > Compilers that don’t understand import-by-semver just ignore the > > > extension, > > no deviation is required. They just import whichever arbitrary > > revision that they > > would have imported anyway, as specified by YANG 1.1. The > > import-by-semver > > statement just reduces the set of valid modules revisions that can be > > used for > > import. > > > > > > > If two compilers (one supporting semver, the other not) resolve > > imports > > differently, then the design is in my view somewhat broken, in > > particular if you > > allow NBC changes. > > But that is true of YANG compilers today. If there are multiple > revisions of a module that could be chosen, then each compiler is at > liberty to decide which revision to choose (last paragraph of section > 5.1.1 in RFC 7950). This is by design, of course. With an "open" import (not import by revision), the server implementor is free to implement any set of modules that work together. > So, I would argue that "import-by-version" doesn't make YANG compilers > any less consistent that they are already today, since that > inconsistency already exists. I don't think I understand Andy's objection. I also think that this is just another implementation detail. > I presume that the real solution here is to explicitly define the full > set of implemented, import-only-modules to the compiler so that it > always compiles a consistent schema. Perhaps other compilers have > different ways to solve this problem. > > Note, I also think that YANG library has a similar inconsistency. > I.e. there is no guarantee that two different compilers will construct > exactly the same datastore schema from the YANG library output. Can you elaborate? Given an instance of YANG library, it should be clear which set of modules are used. > I > think that this is a design bug, but also one that we attempt to > address in draft-verdt-netmod-yang-semver-00. > > Thanks, > Rob > > > > > /js > > > > -- > > Juergen Schoenwaelder Jacobs University Bremen gGmbH > > Phone: +49 421 200 3587 Campus Ring 1 | 28759 Bremen | Germany > > Fax: +49 421 200 3103 <https://www.jacobs-university.de/> > _______________________________________________ > netmod mailing list > netmod@ietf.org > https://www.ietf.org/mailman/listinfo/netmod
- [netmod] import-by-semver issue Andy Bierman
- Re: [netmod] import-by-semver issue Rob Wilton (rwilton)
- Re: [netmod] import-by-semver issue Andy Bierman
- Re: [netmod] import-by-semver issue Rob Wilton (rwilton)
- Re: [netmod] import-by-semver issue Juergen Schoenwaelder
- Re: [netmod] import-by-semver issue Rob Wilton (rwilton)
- Re: [netmod] import-by-semver issue Martin Bjorklund
- Re: [netmod] import-by-semver issue Rob Wilton (rwilton)
- Re: [netmod] import-by-semver issue Juergen Schoenwaelder
- Re: [netmod] import-by-semver issue Andy Bierman
- Re: [netmod] import-by-semver issue Martin Bjorklund