Internet DRAFT - draft-bjorklund-netmod-yang-tree-diagrams
draft-bjorklund-netmod-yang-tree-diagrams
Network Working Group M. Bjorklund
Internet-Draft Tail-f Systems
Intended status: Informational L. Berger, Ed.
Expires: September 14, 2017 LabN Consulting, L.L.C.
March 13, 2017
YANG Tree Diagrams
draft-bjorklund-netmod-yang-tree-diagrams-00
Abstract
This document captures the current syntax used in YANG module Tree
Diagrams. The purpose of the document is to provide a single
location for this definition. This syntax may be updated from time
to time based on the evolution of the YANG language.
Status of This Memo
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This Internet-Draft will expire on September 14, 2017.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Tree Diagram Syntax . . . . . . . . . . . . . . . . . . . . . 2
3. Next Steps . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
5. Informative References . . . . . . . . . . . . . . . . . . . 4
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 4
1. Introduction
YANG Tree Diagrams were first published in [RFC7223]. Such diagrams
are commonly used to provided a simplified graphical representation
of a data model and can be automatically generated via tools such as
"pyang". (See <https://github.com/mbj4668/pyang>). This document
provides the syntax used in YANG Tree Diagrams. It is expected that
this document will be updated or replaced as changes to the YANG
language, see [RFC7950], necessitate.
Today's Common practice is include the definition of the syntax used
to represent a YANG module in every document that provides a tree
diagram. This practice has several disadvantages and the purpose of
the document is to provide a single location for this definition. It
is not the intent of this document to restrict future changes, but
rather to ensure such changes are easily identified and suitably
agreed upon.
An example tree diagram can be found in [RFC7223] Section 3. A
portion of which follows:
+--rw interfaces
| +--rw interface* [name]
| +--rw name string
| +--rw description? string
| +--rw type identityref
| +--rw enabled? boolean
| +--rw link-up-down-trap-enable? enumeration
The remainder of this document contains YANG Tree Diagram syntax
based on output from pyang version 1.7.1.
2. Tree Diagram Syntax
This section provides the meaning of the symbols used in YANG Tree
diagrams.
Each node in a YANG module is printed as:
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<status> <flags> <name> <opts> <type> <if-features>
<status> is one of:
+ for current
x for deprecated
o for obsolete
<flags> is one of:
rw for configuration data
ro for non-configuration data
-x for rpcs and actions
-n for notifications
<name> is the name of the node
(<name>) means that the node is a choice node
:(<name>) means that the node is a case node
If the node is augmented into the tree from another module, its
name is printed as <prefix>:<name>.
<opts> is one of:
? for an optional leaf, choice, anydata or anyxml
! for a presence container
* for a leaf-list or list
[<keys>] for a list's keys
<type> is the name of the type for leafs and leaf-lists
If the type is a leafref, the type is printed as "-> TARGET",
where TARGET is either the leafref path, with prefixed removed
if possible.
<if-features> is the list of features this node depends on,
printed within curly brackets and a question mark "{...}?"
3. Next Steps
Authors' note: This draft is currently a bit rough. The next/future
version is expected to add text covering different types of trees and
when to use them; for example, complete module trees, subtrees, trees
for groupings etc. Maybe also how to deal with the limited line
lengths in RFCs.
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4. IANA Considerations
There are no IANA requests or assignments included in this document.
5. Informative References
[RFC7223] Bjorklund, M., "A YANG Data Model for Interface
Management", RFC 7223, DOI 10.17487/RFC7223, May 2014,
<http://www.rfc-editor.org/info/rfc7223>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<http://www.rfc-editor.org/info/rfc7950>.
Authors' Addresses
Martin Bjorklund
Tail-f Systems
Email: mbj@tail-f.com
Lou Berger (editor)
LabN Consulting, L.L.C.
Email: lberger@labn.net
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