Re: [netmod] augment and if-feature

Martin Bjorklund <mbj@tail-f.com> Tue, 14 March 2017 20:50 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 C25971314F0 for <netmod@ietfa.amsl.com>; Tue, 14 Mar 2017 13:50:44 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -0.002
X-Spam-Level:
X-Spam-Status: No, score=-0.002 tagged_above=-999 required=5 tests=[RP_MATCHES_RCVD=-0.001, SPF_PASS=-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 22QxmSMwEILS for <netmod@ietfa.amsl.com>; Tue, 14 Mar 2017 13:50:43 -0700 (PDT)
Received: from mail.tail-f.com (mail.tail-f.com [46.21.102.45]) by ietfa.amsl.com (Postfix) with ESMTP id 70CFD1314E9 for <netmod@ietf.org>; Tue, 14 Mar 2017 13:50:43 -0700 (PDT)
Received: from localhost (h-148-188.a165.priv.bahnhof.se [176.10.148.188]) by mail.tail-f.com (Postfix) with ESMTPSA id 61DB61AE018C; Tue, 14 Mar 2017 21:50:41 +0100 (CET)
Date: Tue, 14 Mar 2017 21:50:41 +0100
Message-Id: <20170314.215041.1542757804066431921.mbj@tail-f.com>
To: phil@juniper.net
Cc: joey.boyd@adtran.com, netmod@ietf.org
From: Martin Bjorklund <mbj@tail-f.com>
In-Reply-To: <201703142011.v2EKB9Cd072710@idle.juniper.net>
References: <20170314.183950.1234657423841109832.mbj@tail-f.com> <201703142011.v2EKB9Cd072710@idle.juniper.net>
X-Mailer: Mew version 6.7 on Emacs 24.5 / Mule 6.0 (HANACHIRUSATO)
Mime-Version: 1.0
Content-Type: Text/Plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/netmod/MPTRwv_oOFLp2vTCqdAdpZFq4oI>
Subject: Re: [netmod] augment and if-feature
X-BeenThere: netmod@ietf.org
X-Mailman-Version: 2.1.22
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: Tue, 14 Mar 2017 20:50:45 -0000

Phil Shafer <phil@juniper.net> wrote:
> Martin Bjorklund writes:
> >> What are your thoughts on this? Surely, an augment should not have to
> >> contain if-feature statements of all parents of the augmented node.
> >
> >The spec says:
> >
> >   When a server implements a module containing an "augment" statement,
> >   that implies that the server's implementation of the augmented module
> >   contains the additional nodes.
> >
> >Compare with a simple augment of a node w/o an if-feature.  In this
> >case, if the server implements the augmenting module, it MUST also
> >implement the augmented module.
> 
> It implements the module, but it doesn't implement the nodes
> since it doesn't express the feature.  IMHO this is a tool
> bug and/or an errata,since otherwise one has to carry features
> forward, repeating the if-feature using the original modules
> prefix:feature-name on every augment of feature-based nodes.

Well, I agree that it would have been better to state that if a server
doesn't implement the augment target, then it doesn't implement the
augment either.  But the text is pretty clear; this is not how it
works.  This is not appropriate to "fix" in an errata.


/martin