netmod

Summary

The netmod working group met to discuss several topics, including system-defined configuration, sub-interface drafts, guidelines for YANG module RFCs, YANG module versioning, and YANG packages. The group also discussed issues related to reusability in YANG, updating YANG modules with errata, and future directions for YANG development (YANG Next).

Key Discussion Points

System-Defined Configuration: A new revision of the system-defined configuration draft removes copy-related sections. A second working group last call will be initiated.
Sub-interface and Interface Extension YANG: Updates to the sub-interface and interface extension YANG drafts were presented. The interface extension draft will be updated with additional statistics. The working group plans to push these documents to publication.
Guidelines for YANG Module RFCs: Discussion around long trees in YANG modules and clarification of templates for revised models. Concerns were raised about the security templates. A proposal to be explicit about the absence of certain elements in documents (e.g., RPCs, readable data nodes) was debated.
YANG Module Versioning and File Naming: Discussion around file naming conventions, extension statements for non-backwards compatible changes, and the necessity of modifiers in YANG Semver.
YANG Packages: Update on the revived YANG packages work. The discussion focused on keeping the design simple and issues related to deviation handling and schema mounts.
Immutable Flag: Discussion on whether to formally update existing Netconf and Restconf specifications. The group agreed that the document should update the base protocol documents.
Common YANG Data Model for Scheduling: The document is considered stable and a working group last call will be requested, including specific directorates.
YANG Next: A scoring team analyzed open issues. The conclusion was a need to publish a 2.0, with discussion on how to proceed. It was suggested to summarize the groups of features for YANG Next and get consensus before implementation.
Yang++: A project focused on reusability in Yang was presented.
YANG Module Errata: A problem was raised about bugs in YANG modules in published RFCs and slow update processes. A proposal was made to update models using errata and publish them in an official registry.

Decisions and Action Items

System-Defined Configuration: Initiate a second working group last call.
Sub-interface and Interface Extension YANG: Authors to incorporate final comments and prepare for publication.
Guidelines for YANG Module RFCs: Authors to consider the suggestion from the AD about security templates. Workgroup will discuss the updated text and approach on the mailing list.
Immutable Flag: Proceed with updating the relevant RFCs. Robert Wilton to finalise list response and send to list before sending to liaisons.
YANG Packages: Re-announce weekly call details on the mailing list.
YANG Next: Write a draft document capturing the categories of issues being worked on to enable working group adoption of the scope for Yang Next efforts.
YANG Module Errata: Belage to write up a document describing the proposal to update models using errata and publish them in an official registry.

Next Steps

Follow-up discussions on the mailing list for open issues.
Authors to update drafts based on the meeting discussions and prepare for last calls or publication.
Continue weekly YANG Packages discussion.
Address the liaison statement related to the immutable flag.
Proceed with the process described above under Decisions and Action Items.

Session Date/Time: 07 Nov 2024 17:30

netmod

Summary

The NETMOD working group session focused on the topic of configuration templates in YANG. The session included an introduction to the need for standardization, presentations of four different templating ideas, and a discussion regarding the importance of standardization and comparison of the proposed solutions. The main goal was to determine if the working group should pursue standardization of a template mechanism. A poll was conducted which showed a clear majority in favor of standardizing templating.

Key Discussion Points

Need for Standardization: The discussion centered around whether a standardized templating mechanism is necessary, given existing proprietary solutions and the lack of a standard until now. Arguments were made for the benefits of a standard in multi-vendor environments and for mitigating complexity when managing diverse devices.
Scalability: The need for templates to improve the scalability of YANG models on large devices was raised, reducing memory footprint and configuration time.
Existing Solutions: Presentations highlighted different approaches to templating, including adding nodes, deletion, reordering, and even more complex looping and variable usage. A key point was the varying degree of "power" or flexibility offered by each approach.
Validation: A crucial distinction was made regarding whether templates should be validatable and what a system should do if a template application fails validation.
Persistence: The distinction between "fire and forget" vs "persistent" templating solutions, where the system retains knowledge of template application, was discussed.
Impact on YANG Models: Discussion touched on whether templates should affect the YANG language itself (e.g., requiring updates to RFC 7950) or work independently of specific data models. The use of metadata annotations was also discussed.
Coexistence of Solutions: The possibility of annotating templates to indicate which mechanism the template is using.

Decisions and Action Items

Decision: The working group agreed that standardization of a YANG templating mechanism is important and should be pursued.
Action Item: Authors are encouraged to continue developing their template ideas and to present them as drafts.
Action Item: Continue discussion on the NETMOD mailing list to refine requirements and compare proposed solutions.
Action Item: Consider an interim meeting if the volume of discussion on the mailing list warrants it. Otherwise, the topic will be revisited at IETF 122.

Next Steps

Authors will submit drafts outlining their proposed templating solutions.
The working group will continue the discussion on the mailing list, focusing on specific requirements and the trade-offs between different approaches.
The possibility of an interim meeting will be evaluated based on the volume of discussion on the mailing list.