Re: [netconf] [Technical Errata Reported] RFC8040 (6342)

[Andy Bierman <[e-mail]>]

On Mon, Nov 23, 2020 at 5:38 AM Martin Björklund <[e-mail]> wrote:

> Muly Ilan <[e-mail]> wrote:
> > Hi Martin,
> >
> > Putting aside the similarity or not between plain PATCH and PUT, there's
> another example of inconsistency with plain PATCH in the RFC.
> >
> > Please check the plain PATCH example in appendix B.2.5. " Edit a Data
> Resource".
> > This example has keys both in the message header and message body.
> >
> > This means that either the example in 4.6.1 or the example in B.2.5
> should be modified.
>
> No, different examples can show different things.
>
> > Section 4.6.1 includes the following text:
> > "
> > If the target resource represents a YANG list instance, then the key
> > leaf values, in message-body representation, MUST be the same as the
> > key leaf values in the request URI.
> > "
> >
> > If keys are not needed in the message body so this "warning text" is not
> needed either.
>
> It is needed, since keys are *allowed*.  *If* the keys are present,
> they MUST match the existing keys.
>
>
>
Agreed.

Although we have several customers that would like to rename list entries,
and sometimes think RESTCONF allows it.  I do not think any YANG-based
protocol
allows list keys to be modified.  You have to delete and re-create the list
entry.
I think this is something for YANG-next to consider, so it is done
consistently across
all protocols.



> /martin
>

Andy


>
>
> >
> > Moreover, since the above "warning text" is part of the RFC, it suggests
> to me that the RFC assumes that there are keys in both header URI and
> body.
> >
> >
> > Best,
> >
> > Muly
> >
> > -----Original Message-----
> > From: Muly Ilan
> > Sent: 23/11/2020 14:26
> > To: Martin Björklund <[e-mail]>
> > Cc: [e-mail]; [e-mail]; [e-mail]
> > Subject: RE: [netconf] [Technical Errata Reported] RFC8040 (6342)
> >
> > Hi Martin,
> >
> > Plain PATCH is defined as a merge operation i.e. it can create a
> resource.
> > It's not limited to editing of existing resources.
> >
> > From section 4.6.1:
> > " The plain patch mechanism merges the contents of the message-body with
> the target resource."
> >
> > " Plain patch can be used to create or update, but not delete, a child
> resource within the target resource."
> >
> > It's better to have consistent examples.
> > I suggest either to modify the plain PATCH example or the PUT example.
> >
> >
> > Best,
> >
> > Muly
> >
> >
> > -----Original Message-----
> > From: Martin Björklund [mailto:[e-mail]]
> > Sent: 23/11/2020 14:15
> > To: Muly Ilan <[e-mail]>
> > Cc: [e-mail]; [e-mail]; [e-mail]
> > Subject: Re: [netconf] [Technical Errata Reported] RFC8040 (6342)
> >
> > Hi,
> >
> > Muly Ilan <[e-mail]> wrote:
> > > Hi,
> > >
> > > If list keys are not required in message body for plain PATCH then
> > > they are also not required for the PUT method.
> >
> > You are right that the keys are redundant also in PUT.  However, PUT
> means completely replace or create the resource, but plain PATCH modifies
> only the given fields.
> >
> >
> > /martin
> >
> >
> > > But the example for PUT in section 4.5 is:
> > >
> > > PUT /restconf/data/example-jukebox:jukebox/\
> > > library/artist=Foo%20Fighters/album=Wasting%20Light HTTP/1.1
> > > Host: example.com
> > > Content-Type: application/yang-data+json { "example-jukebox:album" : [
> > > { "name" : "Wasting Light", "genre" : "example-jukebox:alternative",
> > > "year" : 2011 } ] }
> > >
> > > So, do we want consistency between PUT and plain PATCH?
> > >
> > > I believe consistency is important and currently the RFC contains two
> > > inconsistent examples.
> > >
> > >
> > > Best,
> > >
> > > Muly
> > >
> > >
> > > -----Original Message-----
> > > From: netconf [mailto:[e-mail]] On Behalf Of Martin
> > > Bj?rklund
> > > Sent: 23/11/2020 10:37
> > > To: [e-mail]
> > > Cc: [e-mail]; [e-mail]
> > > Subject: Re: [netconf] [Technical Errata Reported] RFC8040 (6342)
> > >
> > > Hi,
> > >
> > > The issue boils down to if list keys are required in a plain patch.
> > > Unfortunately, the RFC doesn't specifucy this.  From a technical pow,
> > > list keys are not necessary.  In fact, if they are present in the
> > > payload, they are redundant (since they are part of the URL) (this is
> > > actually mentioned in the RFC).
> > >
> > > Since it isn't clearly specified, I think we must assume that the keys
> > > are not required.  Hence I think that this errata should be rejected.
> > >
> > > In a future version of this document, the behaviour should be
> > > clarified.
> > >
> > >
> > > /martin
> > >
> > >
> > > RFC Errata System <[e-mail]> wrote:
> > > > The following errata report has been submitted for RFC8040,
> > > > "RESTCONF Protocol".
> > > >
> > > > --------------------------------------
> > > > You may review the report below and at:
> > > >
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.
> > > > rfc-editor.org%2Ferrata%2Feid6342&amp;data=04%7C01%7Cmuly_i%40rad.co
> > > > m%
> > > > 7Cf7ffd30dde054f875cc608d88f8b0eed%7Cf9047108cc2c4e4897a343fad1b3bf9
> > > > d%
> > > > 7C1%7C0%7C637417174712193376%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjA
> > > > wM
> > > > DAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=2
> > > > nm
> > > > LthW5HkwRvJZi%2F2Pj6%2B9qkLV9gV55wiBpIoiC%2FD4%3D&amp;reserved=0
> > > >
> > > > --------------------------------------
> > > > Type: Technical
> > > > Reported by: Muly Ilan <[e-mail]>
> > > >
> > > > Section: 4.6.1
> > > >
> > > > Original Text
> > > > -------------
> > > > To replace just the "year" field in the "album" resource (instead of
> > > > replacing the entire resource with the PUT method), the client might
> > > > send a plain patch as follows:
> > > > PATCH /restconf/data/example-jukebox:jukebox/\
> > > > library/artist=Foo%20Fighters/album=Wasting%20Light HTTP/1.1
> > > > Host: example.com
> > > > If-Match: "b8389233a4c"
> > > > Content-Type: application/yang-data+xml <album
> > > > xmlns="https://eur01.safelinks.protection.outlook.com/?url=http%3A%2
> > > > F%25
> > > > 2Fexample.com%2Fns%2Fexample-jukebox&amp;data=04%7C01%7Cmuly_i%40rad
> > > > .c
> > > > om%7Cf7ffd30dde054f875cc608d88f8b0eed%7Cf9047108cc2c4e4897a343fad1b3
> > > > bf
> > > > 9d%7C1%7C0%7C637417174712193376%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4w
> > > > Lj
> > > > AwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdat
> > > > a= hxW6LA8t%2BNRka2GGRqRNsTnK2itYH1rRLnOxU7JbNlc%3D&amp;reserved=0">
> > > > <year>2011</year>
> > > > </album>
> > > >
> > > > Corrected Text
> > > > --------------
> > > > To replace just the "year" field in the "album" resource (instead of
> > > > replacing the entire resource with the PUT method), the client might
> > > > send a plain patch as follows:
> > > > PATCH /restconf/data/example-jukebox:jukebox/\
> > > > library/artist=Foo%20Fighters/album=Wasting%20Light HTTP/1.1
> > > > Host: example.com
> > > > If-Match: "b8389233a4c"
> > > > Content-Type: application/yang-data+xml <album
> > > > xmlns="https://eur01.safelinks.protection.outlook.com/?url=http%3A%2
> > > > F%25
> > > > 2Fexample.com%2Fns%2Fexample-jukebox&amp;data=04%7C01%7Cmuly_i%40rad
> > > > .c
> > > > om%7Cf7ffd30dde054f875cc608d88f8b0eed%7Cf9047108cc2c4e4897a343fad1b3
> > > > bf
> > > > 9d%7C1%7C0%7C637417174712193376%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4w
> > > > Lj
> > > > AwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdat
> > > > a= hxW6LA8t%2BNRka2GGRqRNsTnK2itYH1rRLnOxU7JbNlc%3D&amp;reserved=0">
> > > > <name>Wasting Light</name>
> > > > <year>2011</year>
> > > > </album>
> > > >
> > > > Notes
> > > > -----
> > > > Missing key leaf value in the message-body (<name>Wasting
> > > > Light</name>)
> > > >
> > > > Instructions:
> > > > -------------
> > > > This erratum is currently posted as "Reported". If necessary, please
> > > > use "Reply All" to discuss whether it should be verified or rejected.
> > > > When a decision is reached, the verifying party can log in to change
> > > > the status and edit the report, if necessary.
> > > >
> > > > --------------------------------------
> > > > RFC8040 (draft-ietf-netconf-restconf-18)
> > > > --------------------------------------
> > > > Title               : RESTCONF Protocol
> > > > Publication Date    : January 2017
> > > > Author(s)           : A. Bierman, M. Bjorklund, K. Watsen
> > > > Category            : PROPOSED STANDARD
> > > > Source              : Network Configuration
> > > > Area                : Operations and Management
> > > > Stream              : IETF
> > > > Verifying Party     : IESG
> > > >
> > > > _______________________________________________
> > > > netconf mailing list
> > > > [e-mail]
> > > >
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> > > > d.com%7Cf7ffd30dde054f875cc608d88f8b0eed%7Cf9047108cc2c4e4897a343fad
> > > > 1b
> > > > 3bf9d%7C1%7C0%7C637417174712193376%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiM
> > > > C4
> > > > wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;s
> > > > da
> > > > ta=GOd8xUYLJ9C69r7aN6rujBhsYFJd05CxiHNXT9YXOZ0%3D&amp;reserved=0
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> > > wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sda
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