draft-ietf-netmod-schema-mount-10.txt		draft-ietf-netmod-schema-mount-11.txt
	Network Working Group M. Bjorklund		Network Working Group M. Bjorklund
	Internet-Draft Tail-f Systems		Internet-Draft Tail-f Systems
	Intended status: Standards Track L. Lhotka		Intended status: Standards Track L. Lhotka
	Expires: October 14, 2018 CZ.NIC		Expires: February 8, 2019 CZ.NIC
	April 12, 2018		August 7, 2018
	YANG Schema Mount		YANG Schema Mount
	draft-ietf-netmod-schema-mount-10		draft-ietf-netmod-schema-mount-11
	Abstract		Abstract
	This document defines a mechanism to add the schema trees defined by		This document defines a mechanism to add the schema trees defined by
	a set of YANG modules onto a mount point defined in the schema tree		a set of YANG modules onto a mount point defined in the schema tree
	in some YANG module.		in some YANG module.
	Status of This Memo		Status of This Memo
	This Internet-Draft is submitted in full conformance with the		This Internet-Draft is submitted in full conformance with the
	skipping to change at page 1, line 33 ¶		skipping to change at page 1, line 33 ¶
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at http://datatracker.ietf.org/drafts/current/.		Drafts is at http://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on October 14, 2018.		This Internet-Draft will expire on February 8, 2019.
	Copyright Notice		Copyright Notice
	Copyright (c) 2018 IETF Trust and the persons identified as the		Copyright (c) 2018 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(http://trustee.ietf.org/license-info) in effect on the date of		(http://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	carefully, as they describe your rights and restrictions with respect		carefully, as they describe your rights and restrictions with respect
	to this document. Code Components extracted from this document must		to this document. Code Components extracted from this document must
	include Simplified BSD License text as described in Section 4.e of		include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as		the Trust Legal Provisions and are provided without warranty as
	described in the Simplified BSD License.		described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
	2. Terminology and Notation . . . . . . . . . . . . . . . . . . 5		2. Terminology and Notation . . . . . . . . . . . . . . . . . . 5
	2.1. Glossary of New Terms . . . . . . . . . . . . . . . . . . 6		2.1. Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . 6
	2.2. Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . 6		2.2. Namespace Prefixes . . . . . . . . . . . . . . . . . . . 6
	2.3. Namespace Prefixes . . . . . . . . . . . . . . . . . . . 6
	3. Schema Mount . . . . . . . . . . . . . . . . . . . . . . . . 7		3. Schema Mount . . . . . . . . . . . . . . . . . . . . . . . . 7
	3.1. Mount Point Definition . . . . . . . . . . . . . . . . . 7		3.1. Mount Point Definition . . . . . . . . . . . . . . . . . 7
	3.2. Data Model . . . . . . . . . . . . . . . . . . . . . . . 8		3.2. Data Model . . . . . . . . . . . . . . . . . . . . . . . 8
	3.3. Specification of the Mounted Schema . . . . . . . . . . . 8		3.3. Specification of the Mounted Schema . . . . . . . . . . . 8
	3.4. Multiple Levels of Schema Mount . . . . . . . . . . . . . 9		3.4. Multiple Levels of Schema Mount . . . . . . . . . . . . . 9
	4. Referring to Data Nodes in the Parent Schema . . . . . . . . 9		4. Referring to Data Nodes in the Parent Schema . . . . . . . . 9
	5. RPC operations and Notifications . . . . . . . . . . . . . . 10		5. RPC operations and Notifications . . . . . . . . . . . . . . 10
	6. Network Management Datastore Architecture (NMDA)		6. Network Management Datastore Architecture (NMDA)
	Considerations . . . . . . . . . . . . . . . . . . . . . . . 11		Considerations . . . . . . . . . . . . . . . . . . . . . . . 11
	7. Interaction with the Network Configuration Access Control		7. Interaction with the Network Configuration Access Control
	skipping to change at page 3, line 17 ¶		skipping to change at page 3, line 17 ¶
	these mechanisms are realized through the following YANG statements:		these mechanisms are realized through the following YANG statements:
	o The "uses" statement explicitly incorporates the contents of a		o The "uses" statement explicitly incorporates the contents of a
	grouping defined in the same or another module. See Section 4.2.6		grouping defined in the same or another module. See Section 4.2.6
	of [RFC7950] for more details.		of [RFC7950] for more details.
	o The "augment" statement explicitly adds contents to a target node		o The "augment" statement explicitly adds contents to a target node
	defined in the same or another module. See Section 4.2.8 of		defined in the same or another module. See Section 4.2.8 of
	[RFC7950] for more details.		[RFC7950] for more details.
	With both mechanisms, the source or target YANG module explicitly		With both mechanisms, the YANG module with the "uses" or "augment"
	defines the exact location in the schema tree where the new nodes are		statement explicitly defines the exact location in the schema tree
	placed.		where the new nodes are placed.
	In some cases these mechanisms are not sufficient; it is sometimes		In some cases these mechanisms are not sufficient; it is sometimes
	necessary that an existing module (or a set of modules) is added to		necessary that an existing module (or a set of modules) is added to
	the data model starting at locations other than the root. For		the data model starting at locations other than the root. For
	example, YANG modules such as "ietf-interfaces" [RFC8343] are defined		example, YANG modules such as "ietf-interfaces" [RFC8343] are defined
	so as to be used in a data model of a physical device. Now suppose		so as to be used in a data model of a physical device. Now suppose
	we want to model a device that supports multiple logical devices		we want to model a device that supports multiple logical devices
	[I-D.ietf-rtgwg-lne-model], each of which has its own instantiation		[I-D.ietf-rtgwg-lne-model], each of which has its own instantiation
	of "ietf-interfaces", and possibly other modules, but, at the same		of "ietf-interfaces", and possibly other modules, but, at the same
	time, we want to be able to manage all these logical devices from the		time, we want to be able to manage all these logical devices from the
	skipping to change at page 5, line 14 ¶		skipping to change at page 5, line 14 ¶
	scope of this document, and could be possibly dealt with in a future		scope of this document, and could be possibly dealt with in a future
	revision of the YANG data modeling language.		revision of the YANG data modeling language.
	Schema mount applies to the data model, and specifically does not		Schema mount applies to the data model, and specifically does not
	assume anything about the source of instance data for the mounted		assume anything about the source of instance data for the mounted
	schemas. It may be implemented using the same instrumentation as the		schemas. It may be implemented using the same instrumentation as the
	rest of the system, or it may be implemented by querying some other		rest of the system, or it may be implemented by querying some other
	system. Future specifications may define mechanisms to control or		system. Future specifications may define mechanisms to control or
	monitor the implementation of specific mount points.		monitor the implementation of specific mount points.
			How and when specific mount points are instantiated by the server is
			out of scope for this document. Such mechanisms may be defined in
			future specifications.
	This document allows mounting of complete data models only. Other		This document allows mounting of complete data models only. Other
	specifications may extend this model by defining additional		specifications may extend this model by defining additional
	mechanisms such as mounting sub-hierarchies of a module.		mechanisms such as mounting sub-hierarchies of a module.
	The YANG modules in this document conform to the Network Management		The YANG modules in this document conform to the Network Management
	Datastore Architecture (NMDA) [RFC8342].		Datastore Architecture (NMDA) [RFC8342].
	2. Terminology and Notation		2. Terminology and Notation
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
	skipping to change at page 6, line 4 ¶		skipping to change at page 6, line 8 ¶
	o schema node		o schema node
	o schema tree		o schema tree
	The following terms are defined in [RFC8342] and are not redefined		The following terms are defined in [RFC8342] and are not redefined
	here:		here:
	o client		o client
	o notification		o notification
	o operational state		o operational state
	o server		o server
	The following term is defined in [RFC8343] and are not redefined		The following term is defined in [RFC8343] and is not redefined here:
	here:
	o system-controlled interface		o system-controlled interface
	The following term is defined in [I-D.ietf-netconf-rfc7895bis] and		The following term is defined in [I-D.ietf-netconf-rfc7895bis] is not
	are not redefined here:		redefined here:
	o YANG library checksum		o YANG library checksum
	2.1. Glossary of New Terms		The following additional terms are used within this document:
	o mount point: container or list node whose definition contains the		o mount point: A container or a list node whose definition contains
	"mount-point" extension statement. The argument of the		the "mount-point" extension statement. The argument of the
	"mount-point" statement defines a label for the mount point.		"mount-point" statement defines a label for the mount point.
	o schema: collection of schema trees with a common root		o schema: A collection of schema trees with a common root.
	o top-level schema: schema rooted at the root node		o top-level schema: A schema rooted at the root node.
	o mounted schema: schema rooted at a mount point		o mounted schema: A schema rooted at a mount point.
	o parent schema (of a mounted schema): schema containing the mount		o parent schema (of a mounted schema): A schema containing the mount
	point		point.
	2.2. Tree Diagrams		o schema mount: The mechanism to combine data models defined in this
			document.
			2.1. Tree Diagrams
	Tree diagrams used in this document follow the notation defined in		Tree diagrams used in this document follow the notation defined in
	[RFC8340]		[RFC8340]
	2.3. Namespace Prefixes		2.2. Namespace Prefixes
	In this document, names of data nodes, YANG extensions, actions and		In this document, names of data nodes, YANG extensions, actions and
	other data model objects are often used without a prefix, as long as		other data model objects are often used without a prefix, as long as
	it is clear from the context in which YANG module each name is		it is clear from the context in which YANG module each name is
	defined. Otherwise, names are prefixed using the standard prefix		defined. Otherwise, names are prefixed using the standard prefix
	associated with the corresponding YANG module, as shown in Table 1.		associated with the corresponding YANG module, as shown in Table 1.
	+---------+------------------------+--------------------------------+		+---------+------------------------+--------------------------------+
	| Prefix | YANG module | Reference |		| Prefix | YANG module | Reference |
	+---------+------------------------+--------------------------------+		+---------+------------------------+--------------------------------+
	skipping to change at page 12, line 30 ¶		skipping to change at page 12, line 30 ¶
	o split management: one (master) management session has access to		o split management: one (master) management session has access to
	instance data of both parent and mounted schemas but, in addition,		instance data of both parent and mounted schemas but, in addition,
	an extra session exists for every instance of the mount point,		an extra session exists for every instance of the mount point,
	having access only to the mounted data tree.		having access only to the mounted data tree.
	9. Schema Mount YANG Module		9. Schema Mount YANG Module
	This module references [RFC6991].		This module references [RFC6991].
	<CODE BEGINS> file "ietf-yang-schema-mount@2018-04-05"		<CODE BEGINS> file "ietf-yang-schema-mount@2018-08-07"
	module ietf-yang-schema-mount {		module ietf-yang-schema-mount {
	yang-version 1.1;		yang-version 1.1;
	namespace "urn:ietf:params:xml:ns:yang:ietf-yang-schema-mount";		namespace "urn:ietf:params:xml:ns:yang:ietf-yang-schema-mount";
	prefix yangmnt;		prefix yangmnt;
	import ietf-inet-types {		import ietf-inet-types {
	prefix inet;		prefix inet;
	reference		reference
	"RFC 6991: Common YANG Data Types";		"RFC 6991: Common YANG Data Types";
	skipping to change at page 13, line 42 ¶		skipping to change at page 13, line 42 ¶
	NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'MAY', and		NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'MAY', and
	'OPTIONAL' in the module text are to be interpreted as described		'OPTIONAL' in the module text are to be interpreted as described
	in RFC 2119 (https://tools.ietf.org/html/rfc2119).		in RFC 2119 (https://tools.ietf.org/html/rfc2119).
	This version of this YANG module is part of RFC XXXX		This version of this YANG module is part of RFC XXXX
	(https://tools.ietf.org/html/rfcXXXX); see the RFC itself for		(https://tools.ietf.org/html/rfcXXXX); see the RFC itself for
	full legal notices.";		full legal notices.";
	// RFC Ed.: update the date below with the date of RFC publication		// RFC Ed.: update the date below with the date of RFC publication
	// and remove this note.		// and remove this note.
	revision 2018-04-05 {		revision 2018-08-07 {
	description		description
	"Initial revision.";		"Initial revision.";
	reference		reference
	"RFC XXXX: YANG Schema Mount";		"RFC XXXX: YANG Schema Mount";
	}		}
	/*		/*
	* Extensions		* Extensions
	*/		*/
	skipping to change at page 15, line 47 ¶		skipping to change at page 15, line 47 ¶
	}		}
	choice schema-ref {		choice schema-ref {
	mandatory true;		mandatory true;
	description		description
	"Alternatives for specifying the schema.";		"Alternatives for specifying the schema.";
	container inline {		container inline {
	presence		presence
	"A complete self-contained schema is mounted at the		"A complete self-contained schema is mounted at the
	mount point.";		mount point.";
	description		description
	"This node indicates that the server has mounted		"This node indicates that the server has mounted at least
	'ietf-yang-library' at the mount point, and its		the module 'ietf-yang-library' at the mount point, and
	instantiation provides the information about the mounted		its instantiation provides the information about the
	schema.		mounted schema.
	Different instances of the mount point may have		Different instances of the mount point may have
	different schemas mounted.";		different schemas mounted.";
	}		}
	container shared-schema {		container shared-schema {
	presence		presence
	"The mounted schema together with the 'parent-reference'		"The mounted schema together with the 'parent-reference'
	make up the schema for this mount point.";		make up the schema for this mount point.";
	description		description
	"This node indicates that the server has mounted		"This node indicates that the server has mounted at least
	'ietf-yang-library' at the mount point, and its		the module 'ietf-yang-library' at the mount point, and
	instantiation provides the information about the mounted		its instantiation provides the information about the
	schema. When XPath expressions in the mounted schema		mounted schema. When XPath expressions in the mounted
	are evaluated, the 'parent-reference' leaf-list is taken		schema are evaluated, the 'parent-reference' leaf-list
	into account.		is taken into account.
	Different instances of the mount point MUST have the		Different instances of the mount point MUST have the
	same schema mounted.";		same schema mounted.";
	leaf-list parent-reference {		leaf-list parent-reference {
	type yang:xpath1.0;		type yang:xpath1.0;
	description		description
	"Entries of this leaf-list are XPath 1.0 expressions		"Entries of this leaf-list are XPath 1.0 expressions
	that are evaluated in the following context:		that are evaluated in the following context:
	- The context node is the node in the parent data tree		- The context node is the node in the parent data tree
End of changes. 21 change blocks.
	36 lines changed or deleted		42 lines changed or added
This html diff was produced by rfcdiff 1.47. The latest version is available from http://tools.ietf.org/tools/rfcdiff/