< draft-ietf-netconf-restconf-notif-08.txt		draft-ietf-netconf-restconf-notif-09.txt >
	NETCONF E. Voit		NETCONF E. Voit
	Internet-Draft R. Rahman		Internet-Draft R. Rahman
	Intended status: Standards Track E. Nilsen-Nygaard		Intended status: Standards Track E. Nilsen-Nygaard
	Expires: April 7, 2019 Cisco Systems		Expires: April 22, 2019 Cisco Systems
	A. Clemm		A. Clemm
	Huawei		Huawei
	A. Bierman		A. Bierman
	YumaWorks		YumaWorks
	October 4, 2018		October 19, 2018
	RESTCONF Transport for Event Notifications		Dynamic subscription to YANG Events and Datastores over RESTCONF
	draft-ietf-netconf-restconf-notif-08		draft-ietf-netconf-restconf-notif-09
	Abstract		Abstract
	This document defines a RESTCONF binding to the dynamic subscription		This document provides a RESTCONF binding to the dynamic subscription
	capability of both subscribed notifications and YANG-Push.		capability of both subscribed notifications and YANG-Push.
	Subscriptions to publisher defined event streams or nodes/subtrees of
	YANG Datastores is supported.
	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
	provisions of BCP 78 and BCP 79.		provisions of BCP 78 and BCP 79.
	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 https://datatracker.ietf.org/drafts/current/.		Drafts is at https://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 April 7, 2019.		This Internet-Draft will expire on April 22, 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
	(https://trustee.ietf.org/license-info) in effect on the date of		(https://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
	skipping to change at page 2, line 19 ¶		skipping to change at page 2, line 17 ¶
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
	2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3		2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
	3. Dynamic Subscriptions . . . . . . . . . . . . . . . . . . . . 3		3. Dynamic Subscriptions . . . . . . . . . . . . . . . . . . . . 3
	3.1. Transport Connectivity . . . . . . . . . . . . . . . . . 4		3.1. Transport Connectivity . . . . . . . . . . . . . . . . . 4
	3.2. Discovery . . . . . . . . . . . . . . . . . . . . . . . . 4		3.2. Discovery . . . . . . . . . . . . . . . . . . . . . . . . 4
	3.3. RESTCONF RPCs and HTTP Status Codes . . . . . . . . . . . 4		3.3. RESTCONF RPCs and HTTP Status Codes . . . . . . . . . . . 4
	3.4. Call Flow for Server-Sent Events (SSE) . . . . . . . . . 6		3.4. Call Flow for Server-Sent Events (SSE) . . . . . . . . . 6
	4. QoS Treatment . . . . . . . . . . . . . . . . . . . . . . . . 8		4. QoS Treatment . . . . . . . . . . . . . . . . . . . . . . . . 8
	5. Mandatory JSON and datastore support . . . . . . . . . . . . 8		5. Notification Messages . . . . . . . . . . . . . . . . . . . . 8
	6. Notification Messages . . . . . . . . . . . . . . . . . . . . 8		6. YANG Tree . . . . . . . . . . . . . . . . . . . . . . . . . . 8
	7. YANG Tree . . . . . . . . . . . . . . . . . . . . . . . . . . 8		7. YANG module . . . . . . . . . . . . . . . . . . . . . . . . . 8
	8. YANG module . . . . . . . . . . . . . . . . . . . . . . . . . 9		8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
	9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11		9. Security Considerations . . . . . . . . . . . . . . . . . . . 11
	10. Security Considerations . . . . . . . . . . . . . . . . . . . 11		10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 11
	11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 12		11. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
	12. References . . . . . . . . . . . . . . . . . . . . . . . . . 12		11.1. Normative References . . . . . . . . . . . . . . . . . . 11
	12.1. Normative References . . . . . . . . . . . . . . . . . . 12		11.2. Informative References . . . . . . . . . . . . . . . . . 13
	12.2. Informative References . . . . . . . . . . . . . . . . . 13
	Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 14		Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 14
	A.1. Dynamic Subscriptions . . . . . . . . . . . . . . . . . . 14		A.1. Dynamic Subscriptions . . . . . . . . . . . . . . . . . . 14
	A.1.1. Establishing Dynamic Subscriptions . . . . . . . . . 14		A.1.1. Establishing Dynamic Subscriptions . . . . . . . . . 14
	A.1.2. Modifying Dynamic Subscriptions . . . . . . . . . . . 17		A.1.2. Modifying Dynamic Subscriptions . . . . . . . . . . . 17
	A.1.3. Deleting Dynamic Subscriptions . . . . . . . . . . . 18		A.1.3. Deleting Dynamic Subscriptions . . . . . . . . . . . 18
	A.2. Subscription State Notifications . . . . . . . . . . . . 19		A.2. Subscription State Notifications . . . . . . . . . . . . 19
	A.2.1. subscription-modified . . . . . . . . . . . . . . . . 19		A.2.1. subscription-modified . . . . . . . . . . . . . . . . 19
	A.2.2. subscription-completed, subscription-resumed, and		A.2.2. subscription-completed, subscription-resumed, and
	replay-complete . . . . . . . . . . . . . . . . . . . 20		replay-complete . . . . . . . . . . . . . . . . . . . 20
	A.2.3. subscription-terminated and subscription-suspended . 20		A.2.3. subscription-terminated and subscription-suspended . 20
	skipping to change at page 3, line 31 ¶		skipping to change at page 3, line 31 ¶
	and HTTP2 stream which maps to the definition of "stream" within		and HTTP2 stream which maps to the definition of "stream" within
	[RFC7540], Section 2.		[RFC7540], Section 2.
	[ note to the RFC Editor - please replace XXXX within this document		[ note to the RFC Editor - please replace XXXX within this document
	with the number of this document ]		with the number of this document ]
	3. Dynamic Subscriptions		3. Dynamic Subscriptions
	This section provides specifics on how to establish and maintain		This section provides specifics on how to establish and maintain
	dynamic subscriptions over RESTCONF [RFC8040]. Subscribing to event		dynamic subscriptions over RESTCONF [RFC8040]. Subscribing to event
	streams is accomplished in this way via a RESTCONF POST into RPCs		streams is accomplished in this way via RPCs defined within
	defined within [I-D.draft-ietf-netconf-subscribed-notifications]		[I-D.draft-ietf-netconf-subscribed-notifications] Section 2.4, the
	Section 2.4. YANG datastore subscription is accomplished via		RPCs are done via RESTCONF POSTs. YANG datastore subscription is
	augmentations to [I-D.draft-ietf-netconf-subscribed-notifications] as		accomplished via augmentations to
	described within [I-D.ietf-netconf-yang-push] Section 4.4.		[I-D.draft-ietf-netconf-subscribed-notifications] as described within
			[I-D.ietf-netconf-yang-push] Section 4.4.
	As described in [RFC8040] Section 6.3, a GET needs to be made against		As described in [RFC8040] Section 6.3, a GET needs to be made against
	a specific URI on the publisher. Subscribers cannot pre-determine		a specific URI on the publisher. Subscribers cannot pre-determine
	the URI against which a subscription might exist on a publisher, as		the URI against which a subscription might exist on a publisher, as
	the URI will only exist after the "establish-subscription" RPC has		the URI will only exist after the "establish-subscription" RPC has
	been accepted. The subscription URI will be determined and sent as		been accepted. Therefore, the POST for the "establish-subscription"
	part of the response to the "establish-subscription" RPC, and a		RPC replaces the GET request for the "location" leaf which is used in
	subsequent GET to this URI will be done in order to start the flow of		[RFC8040] to obtain the URI. The subscription URI will be determined
	notification messages back to the subscriber. A subscription does		and sent as part of the response to the "establish-subscription" RPC,
	not move to the active state as per Section 2.4.1. of		and a subsequent GET to this URI will be done in order to start the
			flow of notification messages back to the subscriber. A subscription
			does not move to the active state as per Section 2.4.1. of
	[I-D.draft-ietf-netconf-subscribed-notifications] until the GET is		[I-D.draft-ietf-netconf-subscribed-notifications] until the GET is
	received. The POST for the "establish-subscription" RPC replaces the		received.
	GET request for the "location" leaf which is used in [RFC8040] to
	obtain the URI.
	3.1. Transport Connectivity		3.1. Transport Connectivity
	For a dynamic subscription, where an HTTP client session doesn't		For a dynamic subscription, where a RESTCONF session doesn't already
	already exist, a new client session is initiated from the subscriber.		exist, a new RESTCONF session is initiated from the subscriber.
	As stated in Section 2.1 of [RFC8040], a subscriber MUST establish		As stated in Section 2.1 of [RFC8040], a subscriber MUST establish
	the HTTP session over TLS [RFC5246] in order to secure the content in		the HTTP session over TLS [RFC5246] in order to secure the content in
	transit.		transit.
	Without the involvement of additional protocols, HTTP sessions by		Without the involvement of additional protocols, HTTP sessions by
	themselves do not allow for a quick recognition of when the		themselves do not allow for a quick recognition of when the
	communication path has been lost with the publisher. Where quick		communication path has been lost with the publisher. Where quick
	recognition of the loss of a publisher is required, a subscriber		recognition of the loss of a publisher is required, a subscriber
	SHOULD use a TLS heartbeat [RFC6520], just from receiver to		SHOULD use a TLS heartbeat [RFC6520], just from receiver to
	publisher, to track HTTP session continuity. Loss of the heartbeat		publisher, to track HTTP session continuity.
	MUST result in any subscription related TCP sessions between those
	endpoints being torn down. A subscriber can then attempt to re-		Loss of the heartbeat MUST result in any subscription related TCP
	establish.		sessions between those endpoints being torn down. A subscriber can
			then attempt to re-establish the dynamic subscription by using the
			procedure described in Section 3.
	3.2. Discovery		3.2. Discovery
	Subscribers can learn what event streams a RESTCONF server supports		Subscribers can learn what event streams a RESTCONF server supports
	by querying the "streams" container of ietf-subscribed-		by querying the "streams" container of ietf-subscribed-
	notification.yang in		notification.yang in
	[I-D.draft-ietf-netconf-subscribed-notifications]. Support for the		[I-D.draft-ietf-netconf-subscribed-notifications]. Support for the
	"streams" container of ietf-restconf-monitoring.yang in [RFC6520] is		"streams" container of ietf-restconf-monitoring.yang in [RFC8040] is
	not required.		not required.
	Subscribers can learn what datastores a RESTCONF server supports by		Subscribers can learn what datastores a RESTCONF server supports by
	following [I-D.draft-ietf-netconf-nmda-restconf].		following [I-D.draft-ietf-netconf-nmda-restconf].
	3.3. RESTCONF RPCs and HTTP Status Codes		3.3. RESTCONF RPCs and HTTP Status Codes
	Specific HTTP responses codes as defined in [RFC7231] section 6 will		Specific HTTP responses codes as defined in [RFC7231] section 6 will
	indicate the result of RESTCONF RPC requests with publisher. An HTTP		indicate the result of RESTCONF RPC requests with publisher. An HTTP
	status code of 200 is the proper response to any successful RPC		status code of 200 is the proper response to any successful RPC
	skipping to change at page 5, line 30 ¶		skipping to change at page 5, line 34 ¶
	modify-subscription modify-subscription-error		modify-subscription modify-subscription-error
	delete-subscription delete-subscription-error		delete-subscription delete-subscription-error
	kill-subscription kill-subscription-error		kill-subscription kill-subscription-error
	resynch-subscription resynch-subscription-error		resynch-subscription resynch-subscription-error
	Each error identity will be inserted as the "error-app-tag" using		Each error identity will be inserted as the "error-app-tag" using
	JSON encoding following the form <modulename>:<identityname>. An		JSON encoding following the form <modulename>:<identityname>. An
	example of such as valid encoding would be "ietf-subscribed-		example of such as valid encoding would be "ietf-subscribed-
	notifications:no-such-subscription".		notifications:no-such-subscription".
	o In case of error responses to an "establish-subscription" or		In case of error responses to an "establish-subscription" or "modify-
	"modify-subscription" request there is the option of including an		subscription" request there is the option of including an "error-
	"error-info" node. This node may contain hints for parameter		info" node. This node may contain hints for parameter settings that
	settings that might lead to successful RPC requests in the future.		might lead to successful RPC requests in the future. Following are
	Following are the yang-data structures which may be returned:		the yang-data structures which may be returned:
	establish-subscription returns hints in yang-data structure		establish-subscription returns hints in yang-data structure
	---------------------- ------------------------------------		---------------------- ------------------------------------
	target: event stream establish-subscription-stream-error-info		target: event stream establish-subscription-stream-error-info
	target: datastore establish-subscription-datastore-error-info		target: datastore establish-subscription-datastore-error-info
	modify-subscription returns hints in yang-data structure		modify-subscription returns hints in yang-data structure
	---------------------- ------------------------------------		---------------------- ------------------------------------
	target: event stream modify-subscription-stream-error-info		target: event stream modify-subscription-stream-error-info
	target: datastore modify-subscription-datastore-error-info		target: datastore modify-subscription-datastore-error-info
	skipping to change at page 6, line 26 ¶		skipping to change at page 6, line 26 ¶
	optional leaf "error-reason", as such a leaf would be redundant		optional leaf "error-reason", as such a leaf would be redundant
	with information that is already placed within the		with information that is already placed within the
	"error-app-tag".		"error-app-tag".
	In case of an rpc error as a result of a "delete-subscription", a		In case of an rpc error as a result of a "delete-subscription", a
	"kill-subscription", or a "resynch-subscription" request, no		"kill-subscription", or a "resynch-subscription" request, no
	"error-info" needs to be included, as the "subscription-id" is		"error-info" needs to be included, as the "subscription-id" is
	the only RPC input parameter and no hints regarding this RPC input		the only RPC input parameter and no hints regarding this RPC input
	parameters need to be provided.		parameters need to be provided.
	Note that "error-path" does not need to be included with the "rpc-		Note that "error-path" [RFC8040] does not need to be included with
	error" element, as subscription errors are generally not associated		the "rpc-error" element, as subscription errors are generally
	with nodes in the datastore but with the choice of RPC input		associated with the choice of RPC input parameters.
	parameters.
	3.4. Call Flow for Server-Sent Events (SSE)		3.4. Call Flow for Server-Sent Events (SSE)
	The call flow is defined in Figure 1. The logical connections		The call flow is defined in Figure 1. The logical connections
	denoted by (a) and (b) can be a TCP connection or an HTTP2 stream.		denoted by (a) and (b) can be a TCP connection or an HTTP2 stream
			(multiple HTTP2 streams can be carried in one TCP connection).
	Requests to [I-D.draft-ietf-netconf-subscribed-notifications] or		Requests to [I-D.draft-ietf-netconf-subscribed-notifications] or
	[I-D.ietf-netconf-yang-push] augmented RPCs are sent on a connection		[I-D.ietf-netconf-yang-push] augmented RPCs are sent on a connection
	indicated by (a). A successful "establish-subscription" will result		indicated by (a). A successful "establish-subscription" will result
	in an RPC response returned with both a subscription identifier which		in an RPC response returned with both a subscription identifier which
	uniquely identifies a subscription, as well as a URI which uniquely		uniquely identifies a subscription, as well as a URI which uniquely
	identifies the location of subscription on the publisher (b). This		identifies the location of subscription on the publisher (b). This
	URI is defined via the "uri" leaf the Data Model in Section 8.		URI is defined via the "uri" leaf the Data Model in Section 7.
	An HTTP GET is then sent on a separate logical connection (b) to the		An HTTP GET is then sent on a separate logical connection (b) to the
	URI on the publisher. This initiates the publisher to initiate the		URI on the publisher. This initiates the publisher to initiate the
	flow of notification messages which are sent in SSE [W3C-20150203] as		flow of notification messages which are sent in SSE [W3C-20150203] as
	a response to the GET.		a response to the GET.
	+--------------+ +--------------+		+--------------+ +--------------+
	| Subscriber | | Publisher |		| Subscriber | | Publisher |
	| | | |		| | | |
	| Logical | | Logical |		| Logical | | Logical |
	skipping to change at page 8, line 24 ¶		skipping to change at page 8, line 24 ¶
	4. QoS Treatment		4. QoS Treatment
	To meet subscription quality of service promises, the publisher MUST		To meet subscription quality of service promises, the publisher MUST
	take any existing subscription "dscp" and apply it to the DSCP		take any existing subscription "dscp" and apply it to the DSCP
	marking in the IP header.		marking in the IP header.
	In addition, where HTTP2 transport is available to a notification		In addition, where HTTP2 transport is available to a notification
	message queued for transport to a receiver, the publisher MUST:		message queued for transport to a receiver, the publisher MUST:
	o take any existing subscription "priority" and copy it into the		o take any existing subscription "priority", as specified by the
	HTTP2 stream priority, and		"dscp" leaf node in
			[I-D.draft-ietf-netconf-subscribed-notifications], and copy it
	o take any existing subscription "dependency" and map the HTTP2		into the HTTP2 stream priority, [RFC7540] section 5.3, and
	stream for the parent subscription into the HTTP2 stream
	dependency.
	5. Mandatory JSON and datastore support
	A publisher supporting [I-D.ietf-netconf-yang-push] MUST support the
	"operational" datastore as defined by [RFC8342].
	The "encode-json" feature of		o take any existing subscription "dependency", as specified by the
	[I-D.draft-ietf-netconf-subscribed-notifications] is mandatory to		"dependency" leaf node in
	support. This indicates that JSON is a valid encoding for RPCs,		[I-D.draft-ietf-netconf-subscribed-notifications], and use the
	state change notifications, and subscribed content.		HTTP2 stream for the parent subscription as the HTTP2 stream
			dependency, [RFC7540] section 5.3.1, of the dependent
			subscription.
	6. Notification Messages		5. Notification Messages
	Notification messages transported over HTTP will be encoded using		Notification messages transported over RESTCONF will be encoded
	one-way operation schema defined within [RFC5277], section 4.		according to [RFC8040], section 6.4.
	7. YANG Tree		6. YANG Tree
	The YANG model defined in Section 8 has one leaf augmented into four		The YANG model defined in Section 7 has one leaf augmented into four
	places of [I-D.draft-ietf-netconf-subscribed-notifications], plus two		places of [I-D.draft-ietf-netconf-subscribed-notifications], plus two
	identities. As the resulting full tree is large, it will only be		identities. As the resulting full tree is large, it will only be
	inserted at later stages of this document.		inserted at later stages of this document.
	8. YANG module		7. YANG module
	This module references		This module references
	[I-D.draft-ietf-netconf-subscribed-notifications].		[I-D.draft-ietf-netconf-subscribed-notifications].
	<CODE BEGINS> file "ietf-restconf-subscribed-notifications@2018-10-03.yang"		<CODE BEGINS> file "ietf-restconf-subscribed-notifications@2018-10-19.yang"
	module ietf-restconf-subscribed-notifications {		module ietf-restconf-subscribed-notifications {
	yang-version 1.1;		yang-version 1.1;
	namespace		namespace
	"urn:ietf:params:xml:ns:yang:ietf-restconf-subscribed-notifications";		"urn:ietf:params:xml:ns:yang:ietf-restconf-subscribed-notifications";
	prefix rsn;		prefix rsn;
	import ietf-subscribed-notifications {		import ietf-subscribed-notifications {
	prefix sn;		prefix sn;
	}		}
	skipping to change at page 10, line 6 ¶		skipping to change at page 9, line 50 ¶
	Redistribution and use in source and binary forms, with or without		Redistribution and use in source and binary forms, with or without
	modification, is permitted pursuant to, and subject to the license		modification, is permitted pursuant to, and subject to the license
	terms contained in, the Simplified BSD License set forth in Section		terms contained in, the Simplified BSD License set forth in Section
	4.c of the IETF Trust's Legal Provisions Relating to IETF Documents		4.c of the IETF Trust's Legal Provisions Relating to IETF Documents
	(https://trustee.ietf.org/license-info).		(https://trustee.ietf.org/license-info).
	This version of this YANG module is part of RFC XXXX; see the RFC		This version of this YANG module is part of RFC XXXX; see the RFC
	itself for full legal notices.";		itself for full legal notices.";
	revision 2018-10-03 {		revision 2018-10-19 {
	description		description
	"Initial version";		"Initial version";
	reference		reference
	"RFC XXXX: RESTCONF Transport for Event Notifications";		"RFC XXXX: RESTCONF Transport for Event Notifications";
	}		}
	identity restconf {
	base sn:transport;
	description
	"RESTCONF is used as transport for notification messages and state
	change notifications.";
	}
	grouping uri {		grouping uri {
	description		description
	"Provides a reusable description of a URI.";		"Provides a reusable description of a URI.";
	leaf uri {		leaf uri {
	type inet:uri;		type inet:uri;
	config false;		config false;
	description		description
	"Location of a subscription specific URI on the publisher.";		"Location of a subscription specific URI on the publisher.";
	}		}
	}		}
	augment "/sn:establish-subscription/sn:output" {		augment "/sn:establish-subscription/sn:output" {
	description		description
	"This augmentation allows RESTCONF specific parameters for a		"This augmentation allows RESTCONF specific parameters for a
	response to a publisher's subscription request.";		response to a publisher's subscription request.";
	uses uri;		uses uri;
	}		}
	augment "/sn:subscriptions/sn:subscription" {		augment "/sn:subscriptions/sn:subscription" {
	description		description
	"This augmentation allows RESTCONF specific parameters to be		"This augmentation allows RESTCONF specific parameters to be
	exposed for a subscription.";		exposed for a subscription.";
	uses uri;		uses uri;
	}		}
	augment "/sn:subscription-modified" {		augment "/sn:subscription-modified" {
	description		description
	"This augmentation allows RESTCONF specific parameters to be included		"This augmentation allows RESTCONF specific parameters to be included
	part of the notification that a subscription has been modified.";		part of the notification that a subscription has been modified.";
	uses uri;		uses uri;
	}		}
	}		}
	<CODE ENDS>		<CODE ENDS>
	9. IANA Considerations		8. IANA Considerations
	This document registers the following namespace URI in the "IETF XML		This document registers the following namespace URI in the "IETF XML
	Registry" [RFC3688]:		Registry" [RFC3688]:
	URI: urn:ietf:params:xml:ns:yang:ietf-restconf-subscribed-		URI: urn:ietf:params:xml:ns:yang:ietf-restconf-subscribed-
	notifications		notifications
	Registrant Contact: The IESG.		Registrant Contact: The IESG.
	XML: N/A; the requested URI is an XML namespace.		XML: N/A; the requested URI is an XML namespace.
	This document registers the following YANG module in the "YANG Module		This document registers the following YANG module in the "YANG Module
	Names" registry [RFC6020]:		Names" registry [RFC6020]:
	Name: ietf-restconf-subscribed-notifications		Name: ietf-restconf-subscribed-notifications
	Namespace: urn:ietf:params:xml:ns:yang:ietf-restconf-subscribed-		Namespace: urn:ietf:params:xml:ns:yang:ietf-restconf-subscribed-
	notifications		notifications
	Prefix: rsn		Prefix: rsn
	Reference: RFC XXXX: RESTCONF Transport for Event Notifications		Reference: RFC XXXX: RESTCONF Transport for Event Notifications
	10. Security Considerations		9. Security Considerations
	The YANG module specified in this document defines a schema for data		The YANG module specified in this document defines a schema for data
	that is designed to be accessed via network management transports		that is designed to be accessed via network management transports
	such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF		such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF
	layer is the secure transport layer, and the mandatory-to-implement		layer is the secure transport layer, and the mandatory-to-implement
	secure transport is Secure Shell (SSH) [RFC6242]. The lowest		secure transport is Secure Shell (SSH) [RFC6242]. The lowest
	RESTCONF layer is HTTPS, and the mandatory-to-implement secure		RESTCONF layer is HTTPS, and the mandatory-to-implement secure
	transport is TLS [RFC5246].		transport is TLS [RFC5246].
	The one new data node introduced in this YANG module may be		The one new data node introduced in this YANG module may be
	skipping to change at page 12, line 5 ¶		skipping to change at page 11, line 37 ¶
	or notification) to this data nodes. These are the subtrees and data		or notification) to this data nodes. These are the subtrees and data
	nodes and their sensitivity/vulnerability:		nodes and their sensitivity/vulnerability:
	Container: "/subscriptions"		Container: "/subscriptions"
	o "uri": leaf will show where subscribed resources might be located		o "uri": leaf will show where subscribed resources might be located
	on a publisher. Access control must be set so that only someone		on a publisher. Access control must be set so that only someone
	with proper access permissions, and perhaps even HTTP session has		with proper access permissions, and perhaps even HTTP session has
	the ability to access this resource.		the ability to access this resource.
	11. Acknowledgments		10. Acknowledgments
	We wish to acknowledge the helpful contributions, comments, and		We wish to acknowledge the helpful contributions, comments, and
	suggestions that were received from: Ambika Prasad Tripathy, Alberto		suggestions that were received from: Ambika Prasad Tripathy, Alberto
	Gonzalez Prieto, Susan Hares, Tim Jenkins, Balazs Lengyel, Kent		Gonzalez Prieto, Susan Hares, Tim Jenkins, Balazs Lengyel, Kent
	Watsen, Michael Scharf, Guangying Zheng and Martin Bjorklund.		Watsen, Michael Scharf, Guangying Zheng, Martin Bjorklund and Qin Wu.
	12. References		11. References
	12.1. Normative References		11.1. Normative References
	[I-D.draft-ietf-netconf-subscribed-notifications]		[I-D.draft-ietf-netconf-subscribed-notifications]
	Voit, E., Clemm, A., Gonzalez Prieto, A., Tripathy, A.,		Voit, E., Clemm, A., Gonzalez Prieto, A., Tripathy, A.,
	and E. Nilsen-Nygaard, "Custom Subscription to Event		and E. Nilsen-Nygaard, "Custom Subscription to Event
	Streams", draft-ietf-netconf-subscribed-notifications-13		Streams", draft-ietf-netconf-subscribed-notifications-13
	(work in progress), April 2018.		(work in progress), April 2018.
	[I-D.ietf-netconf-yang-push]		[I-D.ietf-netconf-yang-push]
	Clemm, A., Voit, E., Gonzalez Prieto, A., Prasad Tripathy,		Clemm, A., Voit, E., Gonzalez Prieto, A., Prasad Tripathy,
	A., Nilsen-Nygaard, E., Bierman, A., and B. Lengyel,		A., Nilsen-Nygaard, E., Bierman, A., and B. Lengyel,
	skipping to change at page 13, line 44 ¶		skipping to change at page 13, line 29 ¶
	[RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,		[RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
	and R. Wilton, "Network Management Datastore Architecture		and R. Wilton, "Network Management Datastore Architecture
	(NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,		(NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
	<https://www.rfc-editor.org/info/rfc8342>.		<https://www.rfc-editor.org/info/rfc8342>.
	[W3C-20150203]		[W3C-20150203]
	"Server-Sent Events, World Wide Web Consortium CR CR-		"Server-Sent Events, World Wide Web Consortium CR CR-
	eventsource-20121211", February 2015,		eventsource-20121211", February 2015,
	<https://www.w3.org/TR/2015/REC-eventsource-20150203/>.		<https://www.w3.org/TR/2015/REC-eventsource-20150203/>.
	12.2. Informative References		11.2. Informative References
	[I-D.draft-ietf-netconf-netconf-event-notifications]		[I-D.draft-ietf-netconf-netconf-event-notifications]
	Clemm, Alexander., Voit, Eric., Gonzalez Prieto, Alberto.,		Clemm, Alexander., Voit, Eric., Gonzalez Prieto, Alberto.,
	Nilsen-Nygaard, E., and A. Tripathy, "NETCONF support for		Nilsen-Nygaard, E., and A. Tripathy, "NETCONF support for
	event notifications", May 2018,		event notifications", May 2018,
	<https://datatracker.ietf.org/doc/		<https://datatracker.ietf.org/doc/
	draft-ietf-netconf-netconf-event-notifications/>.		draft-ietf-netconf-netconf-event-notifications/>.
	[I-D.draft-ietf-netconf-nmda-restconf]		[I-D.draft-ietf-netconf-nmda-restconf]
	Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,		Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
	skipping to change at page 15, line 38 ¶		skipping to change at page 15, line 38 ¶
	|<------------------------------|		|<------------------------------|
	| HTTP 200 OK,notif-mesg (id#23)|		| HTTP 200 OK,notif-mesg (id#23)|
	|<------------------------------|		|<------------------------------|
	| |		| |
	Figure 2: Multiple subscriptions over RESTCONF/HTTP		Figure 2: Multiple subscriptions over RESTCONF/HTTP
	To provide examples of the information being transported, example		To provide examples of the information being transported, example
	messages for interactions in Figure 2 are detailed below:		messages for interactions in Figure 2 are detailed below:
	POST /restconf/operations/subscriptions:establish-subscription		POST /restconf/operations/ietf-subscribed-notifications:establish-subscription
	{		{
	"ietf-subscribed-notifications:input": {		"ietf-subscribed-notifications:input": {
	"stream": "NETCONF",		"stream": "NETCONF",
	"stream-xpath-filter": "/ds:foo/",		"stream-xpath-filter": "/example-module:foo/",
	"dscp": "10"		"dscp": "10"
	}
	}		}
			}
	Figure 3: establish-subscription request (a)		Figure 3: establish-subscription request (a)
	As publisher was able to fully satisfy the request, the publisher		As publisher was able to fully satisfy the request, the publisher
	sends the subscription identifier of the accepted subscription, and		sends the subscription identifier of the accepted subscription, and
	the URI:		the URI:
	HTTP status code - 200		HTTP status code - 200
	{		{
	"id": "22",		"id": "22",
	"uri": "/subscriptions/22"		"uri": "https://example.com/restconf/subscriptions/22"
	}		}
	Figure 4: establish-subscription success (b)		Figure 4: establish-subscription success (b)
	Upon receipt of the successful response, the subscriber does a GET		Upon receipt of the successful response, the subscriber does a GET
	the provided URI to start the flow of notification messages. When		the provided URI to start the flow of notification messages. When
	the publisher receives this, the subscription is moved to the active		the publisher receives this, the subscription is moved to the active
	state (c).		state (c).
	GET /restconf/operations/subscriptions/22		GET /restconf/subscriptions/22
	Figure 5: establish-subscription subsequent POST		Figure 5: establish-subscription subsequent POST
	While not shown in Figure 2, if the publisher had not been able to		While not shown in Figure 2, if the publisher had not been able to
	fully satisfy the request, or subscriber has no authorization to		fully satisfy the request, or subscriber has no authorization to
	establish the subscription, the publisher would have sent an RPC		establish the subscription, the publisher would have sent an RPC
	error response. For instance, if the "dscp" value of 10 asserted by		error response. For instance, if the "dscp" value of 10 asserted by
	the subscriber in Figure 3 proved unacceptable, the publisher may		the subscriber in Figure 3 proved unacceptable, the publisher may
	have returned:		have returned:
	skipping to change at page 18, line 5 ¶		skipping to change at page 18, line 5 ¶
	| |		| |
	Figure 7: Interaction model for successful subscription modification		Figure 7: Interaction model for successful subscription modification
	If the subscription being modified in Figure 7 is a datastore		If the subscription being modified in Figure 7 is a datastore
	subscription as per [I-D.ietf-netconf-yang-push], the modification		subscription as per [I-D.ietf-netconf-yang-push], the modification
	request made in (d) may look like that shown in Figure 8. As can be		request made in (d) may look like that shown in Figure 8. As can be
	seen, the modifications being attempted are the application of a new		seen, the modifications being attempted are the application of a new
	xpath filter as well as the setting of a new periodic time interval.		xpath filter as well as the setting of a new periodic time interval.
	POST /restconf/operations/subscriptions:modify-subscription		POST /restconf/operations/ietf-subscribed-notifications:modify-subscription
	{		{
	"ietf-subscribed-notifications:input": {		"ietf-subscribed-notifications:input": {
	"id": "23",		"id": "23",
	"ietf-yang-push:datastore-xpath-filter": "/ds:foo/ds:bar",		"ietf-yang-push:datastore-xpath-filter": "/example-module:foo/example-module:bar",
	"ietf-yang-push:periodic": {		"ietf-yang-push:periodic": {
	"ietf-yang-push:period": "500"		"ietf-yang-push:period": "500"
	}		}
	}		}
	}		}
	Figure 8: Subscription modification request (c)		Figure 8: Subscription modification request (c)
	If the publisher can satisfy both changes, the publisher sends a		If the publisher can satisfy both changes, the publisher sends a
	positive result for the RPC. If the publisher cannot satisfy either		positive result for the RPC. If the publisher cannot satisfy either
	of the proposed changes, the publisher sends an RPC error response		of the proposed changes, the publisher sends an RPC error response
	(e). The following is an example RPC error response for (e) which		(e). The following is an example RPC error response for (e) which
	includes a hint. This hint is an alternative time period value which		includes a hint. This hint is an alternative time period value which
	might have resulted in a successful modification:		might have resulted in a successful modification:
	skipping to change at page 19, line 5 ¶		skipping to change at page 19, line 5 ¶
	}		}
	}		}
	Figure 9: Modify subscription failure with Hint (e)		Figure 9: Modify subscription failure with Hint (e)
	A.1.3. Deleting Dynamic Subscriptions		A.1.3. Deleting Dynamic Subscriptions
	The following demonstrates deleting a subscription. This		The following demonstrates deleting a subscription. This
	subscription may have been to either a stream or a datastore.		subscription may have been to either a stream or a datastore.
	POST /restconf/operations/subscriptions:delete-subscription		POST /restconf/operations/ietf-subscribed-notifications:delete-subscription
	{		{
	"delete-subscription": {		"delete-subscription": {
	"id": "22"		"id": "22"
	}		}
	}		}
	Figure 10: Delete subscription		Figure 10: Delete subscription
	If the publisher can satisfy the request, the publisher replies with		If the publisher can satisfy the request, the publisher replies with
	success to the RPC request.		success to the RPC request.
	If the publisher cannot satisfy the request, the publisher sends an		If the publisher cannot satisfy the request, the publisher sends an
	error-rpc element indicating the modification didn't work. Figure 11		error-rpc element indicating the modification didn't work. Figure 11
	shows a valid response for existing valid subscription identifier,		shows a valid response for existing valid subscription identifier,
	but that subscription identifier was created on a different transport		but that subscription identifier was created on a different transport
	skipping to change at page 20, line 10 ¶		skipping to change at page 20, line 10 ¶
	A.2.1. subscription-modified		A.2.1. subscription-modified
	A "subscription-modified" encoded in JSON would look like:		A "subscription-modified" encoded in JSON would look like:
	{		{
	"ietf-restconf:notification" : {		"ietf-restconf:notification" : {
	"eventTime": "2007-09-01T10:00:00Z",		"eventTime": "2007-09-01T10:00:00Z",
	"ietf-subscribed-notifications:subscription-modified": {		"ietf-subscribed-notifications:subscription-modified": {
	"id": "39",		"id": "39",
	"transport": "RESTCONF",		"uri": "https://example.com/restconf/subscriptions/22"
	"stream-xpath-filter": "/ex:foo",		"stream-xpath-filter": "/example-module:foo",
	"stream": {		"stream": {
	"ietf-netconf-subscribed-notifications" : "NETCONF"		"ietf-netconf-subscribed-notifications" : "NETCONF"
	}		}
	}		}
	}		}
	}		}
	Figure 12: subscription-modified subscription state notification		Figure 12: subscription-modified subscription state notification
	A.2.2. subscription-completed, subscription-resumed, and replay-		A.2.2. subscription-completed, subscription-resumed, and replay-
	skipping to change at page 22, line 5 ¶		skipping to change at page 22, line 5 ¶
	Figure 15: RFC 8347 (VRRP) - Example Notification		Figure 15: RFC 8347 (VRRP) - Example Notification
	Suppose a subscriber wanted to establish a subscription which only		Suppose a subscriber wanted to establish a subscription which only
	passes instances of event records where there is a "checksum-error"		passes instances of event records where there is a "checksum-error"
	as part of a VRRP protocol event. Also assume the publisher places		as part of a VRRP protocol event. Also assume the publisher places
	such event records into the NETCONF stream. To get a continuous		such event records into the NETCONF stream. To get a continuous
	series of matching event records, the subscriber might request the		series of matching event records, the subscriber might request the
	application of an XPath filter against the NETCONF stream. An		application of an XPath filter against the NETCONF stream. An
	"establish-subscription" RPC to meet this objective might be:		"establish-subscription" RPC to meet this objective might be:
	POST /restconf/operations/subscriptions:establish-subscription		POST /restconf/operations/ietf-subscribed-notifications:establish-subscription
	{		{
	"ietf-subscribed-notifications:input": {		"ietf-subscribed-notifications:input": {
	"stream": "NETCONF",		"stream": "NETCONF",
	"stream-xpath-filter": "/ietf-vrrp:vrrp-protocol-error-event[protocol-error-reason='checksum-error']/",		"stream-xpath-filter": "/ietf-vrrp:vrrp-protocol-error-event[protocol-error-reason='checksum-error']/",
	}		}
	}		}
	Figure 16: Establishing a subscription error reason via XPATH		Figure 16: Establishing a subscription error reason via XPath
	For more examples of xpath filters, see [XPATH].		For more examples of XPath filters, see [XPATH].
	Suppose the "establish-subscription" in Figure 16 was accepted. And		Suppose the "establish-subscription" in Figure 16 was accepted. And
	suppose later a subscriber decided they wanted to broaden this		suppose later a subscriber decided they wanted to broaden this
	subscription cover to all VRRP protocol events (i.e., not just those		subscription cover to all VRRP protocol events (i.e., not just those
	with a "checksum error"). The subscriber might attempt to modify the		with a "checksum error"). The subscriber might attempt to modify the
	subscription in a way which replaces the XPath filter with a subtree		subscription in a way which replaces the XPath filter with a subtree
	filter which sends all VRRP protocol events to a subscriber. Such a		filter which sends all VRRP protocol events to a subscriber. Such a
	"modify-subscription" RPC might look like:		"modify-subscription" RPC might look like:
	POST /restconf/operations/subscriptions:modify-subscription		POST /restconf/operations/ietf-subscribed-notifications:modify-subscription
	{		{
	"ietf-subscribed-notifications:input": {		"ietf-subscribed-notifications:input": {
	"stream": "NETCONF",		"stream": "NETCONF",
	"stream-subtree-filter": "/ietf-vrrp:vrrp-protocol-error-event/",		"stream-subtree-filter": {
	}		"/ietf-vrrp:vrrp-protocol-error-event" : {}
	}		}
			}
			}
	Figure 17		Figure 17
	For more examples of subtree filters, see [RFC6241], section 6.4.		For more examples of subtree filters, see [RFC6241], section 6.4.
	Appendix B. Changes between revisions		Appendix B. Changes between revisions
	(To be removed by RFC editor prior to publication)		(To be removed by RFC editor prior to publication)
			v08 - v09
			o Addressed comments received during WGLC.
	v07 - v08		v07 - v08
	o Aligned with RESTCONF mechanism.		o Aligned with RESTCONF mechanism.
	o YANG model: removed augment of subscription-started, added		o YANG model: removed augment of subscription-started, added
	restconf transport.		restconf transport.
	o Tweaked Appendix A.1 to match draft-ietf-netconf-netconf-event-		o Tweaked Appendix A.1 to match draft-ietf-netconf-netconf-event-
	notifications-13.		notifications-13.
End of changes. 53 change blocks.
	126 lines changed or deleted		120 lines changed or added
This html diff was produced by rfcdiff 1.48. The latest version is available from http://tools.ietf.org/tools/rfcdiff/