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

[Balázs Lengyel <[e-mail]>]

Hello Andy,

Looking through the use-cases I think the producer will always know whether it includes default values or not. This is the case if the instance data set is produced by the server e.g. in UC4, UC5,  or if it created by some design activity UC1, UC2, UC3, UC8. (UC6 and UC7 are so broad and loosely defined it is hard to say much about them.)

 

Once the producer knows whether defaults are included or not it can set the include-defaults accordingly, so the default value for include-defaults is not so important. However, I chose trim as the default because:

*	during the WGLC the draft explicitly stated that defaults SHOULD NOT be included and the WG was happy/ok with that
*	IMHO It is better to have short files, 

 

Note, I used the term producer, as IMHO the above is true in all cases whether the server produces the file or some design activity creates the server.

Regards Balazs

 

From: netmod <[e-mail]> On Behalf Of Andy Bierman
Sent: 2021. július 8., csütörtök 19:16
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