Andy Bierman <a...@yumaworks.com> wrote:
> On Thu, Jul 30, 2015 at 10:41 AM, Martin Bjorklund <m...@tail-f.com> wrote:
>
> > Andy Bierman <a...@yumaworks.com> wrote:
> > > On Wed, Jul 29, 2015 at 10:51 AM, Martin Bjorklund <m...@tail-f.com>
> > wrote:
> > >
> > > > Andy Bierman <a...@yumaworks.com> wrote:
> > > > > Hi,
> > > > >
> > > > > I understand the intent is that an implementation of NACM
> > > > > has to understand these NACM extensions. I agree with Lada
> > > > > that the YANG text about MAY ignore extensions casts doubt whether
> > > > > this sort of NACM rule is enforceable or specified correctly.
> > > >
> > > > So do you agree that it would be a good idea to clarify this
> > > > according to Juergen's suggestion?
> > > >
> > > >
> > > >
> > > Not really.
> > > Pretending the extension is just another description-stmt
> > > does not really fix anything.
> > >
> > > A real YANG statement like config-stmt or a new statement
> > > called ephemeral-stmt can be modified with refine-stmt
> > > or deviate-stmt. This can never happen for
> > > an external statement.
> >
> > There are two separate issues here:
> >
> > 1) It seems we are in agreement that if a model uses an extension
> > statement, it is normative (like ietf-system's usage of nacm:*).
> >
> > Should we somehow clarify this in 6020bis?
> >
> > 2) Extensions cannot be refined or deviated.
> >
> > Actually, the *syntax* rules allows things like:
> >
> > deviation /x:foo {
> > deviate replace {
> > i2rs:ephemeral true;
> > }
> > }
> >
> > I agree that it not clear what this means, but we could also
> > clarify this in 6020bis.
> >
> >
>
> But this will take even longer than just defining the statements that
> are needed for ephemeral state, so no point in doing that.
>
> The text in 7.18.3.2 clearly does not support the example above at all.
The grammar allows extensions everywhere, so the example is (as I
wrote) syntactically valid.
> Only one of the keywords listed in the table are supported.
The text doesn't say so, and anyway my point was that - regardless of
the outcome of the ephemeral dicussion - it might be a good a idea to
clarify that extensions can be deviated as well.
/martin
>
>
> The substatement's keyword MUST match a corresponding
> keyword in the target node, and the argument's string MUST be equal
> to the corresponding keyword's argument string in the target node.
>
> The deviates's Substatements
>
> +--------------+---------+-------------+
> | substatement | section | cardinality |
> +--------------+---------+-------------+
> | config | 7.19.1 | 0..1 |
> | default | 7.6.4 | 0..1 |
> | mandatory | 7.6.5 | 0..1 |
> | max-elements | 7.7.4 | 0..1 |
> | min-elements | 7.7.3 | 0..1 |
> | must | 7.5.3 | 0..n |
> | type | 7.4 | 0..1 |
> | unique | 7.8.3 | 0..n |
> | units | 7.3.3 | 0..1 |
> +--------------+---------+-------------+
>
>
>
>
> > > IMO ephemeral data support needs to be a real statement
> > > that can be used with refine-stmt and deviate-stmt.
> > > It is a real property of a data node.
> >
> > Note: it is still not clear that such a statement (base or extension)
> > is needed at all.
> >
> >
>
> Maybe not to you, but according to the I2RS ephemeral requirements,
> it is needed, so unless you have a better plan, this is the default.
>
> Explain how ephemeral state can be identified within a data node.
> It must be possible to use groupings to define such data nodes.
> If must be possible to refine these groupings.
> It must be possible for a vendor to write deviation statements.
> All YANG tools must recognize the ephemeral data property.
> It should not be isolated to a particular YANG module, which would
> create a dependency in all future YANG modules.
>
>
> Andy
>
>
>
>
>
> >
> > /martin
> >
_______________________________________________
netmod mailing list
netmod@ietf.org
https://www.ietf.org/mailman/listinfo/netmod
