Re: [netmod] yang-instance-file include-defaults leaf

["Rob Wilton (rwilton)" <[e-mail]>]

Andy,

Yes, when I suggested this, I was thinking that a boolean flag might be sufficient.  My point being that automatically filtering out default values isn’t always the right thing to do.

E.g., something along these lines:

leaf exclude-defaults {
  type boolean;
  default true;
  description
    “Can be used to reduce the size of the content data file.

      When unset or set to true, data nodes that have a default defined and
      where the actual value is the default value are excluded from the content
      data.

      When set to false, data nodes with default value are not filtered, and
      may appear in the content data.”
}

Would this satisfy your concern?

Regards,
Rob


From: netmod <[e-mail]> On Behalf Of Andy Bierman
Sent: 08 July 2021 18:16
To: NetMod WG <[e-mail]>
Subject: [netmod] yang-instance-file include-defaults leaf

Hi,

The module has this object:


    leaf includes-defaults {

       type enumeration {

         enum report-all {

           value 1;

           description

             "All data nodes SHOULD be included independent of

               any default values.";

         }

         enum trim {

           value 2;

           description

             "Data nodes that have a default defined and where

               the actual value is the default value SHOULD

               NOT be included.";

         }

         enum explicit {

           value 3;

           description

             "Data nodes that have a default defined and where

               the actual value is the default value SHOULD NOT be

               included. However, if the actual value was set by

               a NETCONF client or other management application

               by the way of an explicit management operation the

               data node SHOULD be included.";

         }

       }

       default trim;


The draft is extremely server-centric, like most IETF standards, but this
leaf is too server-centric to ignore.

Consider the possibility that the source of the file is NOT a NETCONF server.
This data may not be known so the default of "trim" may not be correct.

IMO this leaf is noise because any tool that knows the schema will also
know the YANG defaults.  The solution is incomplete anyway because
the presence of a leaf that has a YANG default is not enough.
The  "report-all-tagged" mode must be used to identify defaults.
IMO this leaf should be removed, but at least add an enum called "unknown".


Andy