NETMOD Q. Ma, Ed. Internet-Draft C. Feng Updates: RFC6241, RFC8040, RFC8342 (if approved) Q. Wu Intended status: Standards Track Huawei Expires: 28 April 2022 25 October 2021 System-defined Configuration draft-ma-netmod-with-system-00 Abstract This document updates NMDA [RFC 8342] to define a read-only conventional configuration datastore called "system" to hold system- defined configurations. To support non-NMDA servers, a "with-system" parameter has been defined to return and system-defined configuration combined. The solution enables clients to reference nodes defined in , overwrite values of configurations defined in , and configure descendant nodes of system-defined nodes. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on 28 April 2022. Copyright Notice Copyright (c) 2021 IETF Trust and the persons identified as the document authors. All rights reserved. Ma, et al. Expires 28 April 2022 [Page 1] Internet-Draft System-defined Configuration October 2021 This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 1.2. Requirements Language . . . . . . . . . . . . . . . . . . 4 1.3. Updates to RFC 6241 . . . . . . . . . . . . . . . . . . . 4 1.4. Updates to RFC 8040 . . . . . . . . . . . . . . . . . . . 5 2. Kinds of System Configuration . . . . . . . . . . . . . . . . 5 2.1. Immediately-Active . . . . . . . . . . . . . . . . . . . 5 2.2. Conditionally-Active . . . . . . . . . . . . . . . . . . 6 2.3. Inactive-Until-Referenced . . . . . . . . . . . . . . . . 6 3. Static Characteristics . . . . . . . . . . . . . . . . . . . 6 3.1. Read-only to Clients . . . . . . . . . . . . . . . . . . 6 3.2. May Change via Software Upgrades . . . . . . . . . . . . 6 3.3. No Impact to . . . . . . . . . . . . . . . 7 4. Dynamic Behavior . . . . . . . . . . . . . . . . . . . . . . 7 4.1. Conceptual Model . . . . . . . . . . . . . . . . . . . . 7 4.2. Modifying (overriding) system configuration . . . . . . . 8 4.3. Explicit declaration of system configuration . . . . . . 8 4.4. Examples . . . . . . . . . . . . . . . . . . . . . . . . 9 4.4.1. Modifying A System-instantiated Leaf's Value . . . . 9 4.4.2. Configuring Descendant Nodes of A System-defined Node . . . . . . . . . . . . . . . . . . . . . . . . 11 4.4.3. Declaring A System-defined Node in Explicitly . . . . . . . . . . . . . . . . . . . . . 13 5. Discovering System Configuration . . . . . . . . . . . . . . 13 5.1. The "with-system" Query Parameter . . . . . . . . . . . . 14 5.2. The Configuration Datastore . . . . . . . . . . 14 6. The "ietf-netconf-with-system" Module . . . . . . . . . . . . 15 6.1. Data Model Overview . . . . . . . . . . . . . . . . . . . 15 6.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 16 6.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 17 7. The "ietf-system-datastore" Module . . . . . . . . . . . . . 19 7.1. Data Model Overview . . . . . . . . . . . . . . . . . . . 19 7.2. Example Usage . . . . . . . . . . . . . . . . . . . . . . 20 7.3. YANG Module . . . . . . . . . . . . . . . . . . . . . . . 20 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21 8.1. The "IETF XML" Registry . . . . . . . . . . . . . . . . . 21 8.2. The "YANG Module Names" Registry . . . . . . . . . . . . 22 Ma, et al. Expires 28 April 2022 [Page 2] Internet-Draft System-defined Configuration October 2021 9. Security Considerations . . . . . . . . . . . . . . . . . . . 22 9.1. Regarding the "ietf-netconf-with-system" YANG Module . . 22 9.2. Regarding the "ietf-system-datastore" YANG Module . . . . 23 10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 23 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 23 References . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Normative References . . . . . . . . . . . . . . . . . . . . . 23 Informative References . . . . . . . . . . . . . . . . . . . . 24 Appendix A. Key Use Cases . . . . . . . . . . . . . . . . . . . 24 A.1. Device Powers On . . . . . . . . . . . . . . . . . . . . 24 A.2. Client Commits Configuration . . . . . . . . . . . . . . 25 A.3. Operator Installs Card into a Chassis . . . . . . . . . . 26 Appendix B. Changes between Revisions . . . . . . . . . . . . . 27 Appendix C. Open Issues tracking . . . . . . . . . . . . . . . . 28 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 28 1. Introduction NMDA Architecture [RFC8342] defines system configuration as the configuration that is supplied by the device itself and should be present in when it is in use. However, there is a desire to enable a server to better document the system configuration. Clients can benefit from a standard mechanism to see what system configuration is available in a server. In some cases, a client or offline tool may consider the configuration in or invalid due to references (e.g. leafref) to system configuration data that isn't returned when the datastore is read. The server may accept a configuration (i.e. by internally merging the client specified contents of with the server-provided system configuration and validating the result), but the client or offline tool would consider the datastore contents as invalid. Having to copy the entire contents of the system configuration into should be avoided or reduced when possible. In some other cases, configuration of descendant nodes of system defined configuration needs to be supported. For example, the system configuration may contain an almost empty physical interface, while the client needs to be able to add, modify, remove a number of descendant nodes. Some descendant nodes may not be modifiable (e.g. "name" and "type" set by the system). In all cases, the clients should have control over the configurations ,i.e., read-back of should contain only what was explicitly set by clients. Ma, et al. Expires 28 April 2022 [Page 3] Internet-Draft System-defined Configuration October 2021 This document updates NMDA [RFC 8342] to define a read-only conventional configuration datastore called "system" to hold system- defined configurations. To support non-NMDA servers, a "with-system" parameter has been defined to return and system-defined configuration combined. The solution enables clients to reference nodes defined in , overwrite values of configurations defined in , and configure descendant nodes of system-defined nodes. 1.1. Terminology This document assumes that the reader is familiar with the contents of [RFC6241], [RFC7950], [RFC8342], [RFC8407], and [RFC8525] and uses terminologies from those documents. The following terms are defined in this document as follows: System configuration: Configuration that is provided by the system itself [RFC8342]. Conventional configuration datastore: One of the following set of configuration datastores: , , , , and . These datastores share a common datastore schema, and protocol operations allow copying data between these datastores. The term "conventional" is chosen as a generic umbrella term for these datastores. System configuration datastore: A configuration datastore holding the complete configuration provided by the system itself. This datastore is referred to as "". 1.2. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 1.3. Updates to RFC 6241 The and RPC operations defined in [RFC6241] are augmented to accept additional new input parameter "with-system" which carries no value. The retrieval of implicit hidden system configuration in can be used through or operation with the presence of "with-system" parameter. Ma, et al. Expires 28 April 2022 [Page 4] Internet-Draft System-defined Configuration October 2021 The implicit hidden system configuration will contain all three types of system configurations defined in Section 2. Note that the RPC operation defined in [RFC8526] can also be augmented to retrieve the system configuration from . But not sure whether the new client only supports operation or supports both operation and operation. 1.4. Updates to RFC 8040 This document extends Section 4.8 of [RFC8040] to add a new query parameter "with-system". The "with-system" parameter controls whether implicitly hidden system configuration will be returned in the reply. This parameter is only allowed with no values carried. If this parameter has any unexpected value, then a "400 Bad Request" status-line is returned. +------------+---------+-----------------------------------------+ | Name | Methods | Description | +-------------+---------+-----------------------------------------+ | with-system | GET, | indicates that the implicitly hidden | | | HEAD | system configuration should be returned.| | | | If not specified, then no implicitly | | | | hidden system configuration should be | | | | returned. This parameter can be given | | | | in any order. | +-------------+---------+-----------------------------------------+ 2. Kinds of System Configuration There are three types of system configurations: immediately-activated system configuration, conditionally-activated system configuration and inactivated-until-referenced system configuration. 2.1. Immediately-Active Immediately-active system configurations are those applied and active immediately (e.g., a loop-back interface) , irrespective of physical resource present or not, a special functionality enabled or not. Ma, et al. Expires 28 April 2022 [Page 5] Internet-Draft System-defined Configuration October 2021 2.2. Conditionally-Active System configurations which are provided and activated based on specific conditions being met in a system, e.g.,if a physical resource is present (e.g., insert interface card), the system will automatically detect it and load pre-provisioned configuration; when the physical resource is not present( remove interface card), the system configuration will be automatically cleared. Another example is when a special functionality is enabled, e.g., when QoS function is enabled, QoS policies are automatically created by the system. 2.3. Inactive-Until-Referenced There are some predefined objects(e.g., application ids, anti-x signatures, trust anchor certs, etc) as a convenience for the clients. The clients can also define their own data objects for their unique requirements. Inactive-until-referenced system configurations are not applied and active immediately but only after they are referenced by client defined configuration. 3. Static Characteristics 3.1. Read-only to Clients From the clients' perspective, the contents of the datastore are read-only. There is no way to delete system configuration from a server. Any deletable system-provided configuration must be defined in [RFC 8808], which is used to initialize when the device is first-time powered on or reset to its factory default condition. 3.2. May Change via Software Upgrades System configuration MAY change dynamically, e.g., depending on factors like during device upgrade or system-controlled resources(e.g., HW available) . In some implementations, when QoS function is enabled, QoS-related predefined policies are created by system. If the system configuration gets changed, YANG notification (e.g., "push-change-update" notification)[RFC8641][RFC8639][RFC6470] can be used to notify the client. Ma, et al. Expires 28 April 2022 [Page 6] Internet-Draft System-defined Configuration October 2021 3.3. No Impact to This work intends to have no impact to . As always, system configuration will appear in with "origin=system". This work enables a subset of those system generated nodes to be defined like configuration, i.e., made visible to clients in order for being referenced or configurable prior to present in . "Config false" nodes are completely out of scope, hence existing "config false" nodes are not impacted by this work. 4. Dynamic Behavior 4.1. Conceptual Model This document introduces an optional datastore named "system" which is used to hold all three types of system configurations defined in Section 2. When the device is powered on, immediately-activated system configuration will be provided and activated immediately but inactivated-until-referenced system configuration only becomes active if it is referenced by client defined configuration. While conditionally-activated system configuration will be created and immediately activated if the condition on system resources is met when the device is powered on or running. All these system configuration will be implicitly hidden in the , hence the client can retrieve them through standard operations defined in YANG-driven management protocols such as NETCONF and RESTCONF with a "with-system" query parameter. So that the client can get a merged view from the server. If the datastore exists, all above three types of system configurations will also go into . Then the server will merge and to create , in which process, MAY overwrite and/or extend . If a server implements , MUST be merged into . When the client needs to configure the descendant nodes of system configuration(e.g., a physical interfaces), the ancestor system configuration needs to be configured in explicitly. Ma, et al. Expires 28 April 2022 [Page 7] Internet-Draft System-defined Configuration October 2021 4.2. Modifying (overriding) system configuration In some cases, a server may allow some parts of system configuration to be modified. List keys in system configuration can't be changed by a client, but other descendant nodes in a list entry may be modifiable or non-modifiable. Leafs and leaf-lists outside of lists may also be modifiable or non-modifiable. Modification of system configuration is achieved by the client writing configuration to that overrides the system configuration. Client configuration statements in take precedence over system configuration nodes in if the server allows the nodes to be modified. If a system configuration node is non-modifiable, then writing a value for that node in returns an error. A server may also allow a client to add data nodes to a list entry in by writing those additional nodes in . Those additional data nodes may not exist in (i.e. an *addition* rather than an override). While modifying (overriding) system configuration nodes may be supported by a server, there is no mechanism for deleting a system configuration node. A "mandatory true" leaf, for example, may have a value in which can be modified (overridden) by a client setting that leaf to a value in . But the leaf could not be deleted. Comment 1: What if contains a set of values for a leaf-list, and a client configures another set of values for that leaf-list in , will the set of values in completely replace the set of values in ? Or the two sets of values are merged together? Comment 2: how "ordered-by user" lists and leaf-lists are merged? Do the values go before or after, or is this a case where a full-replace is needed. 4.3. Explicit declaration of system configuration In addition to modifying system configuration, and adding nodes to lists in system configuration as described above, a client can also explicitly declare system configuration nodes in with the same values as in . When a client configures a node (list entry, leaf, etc) in that matches the same node & value in , then that node becomes part of . A read of returns those explicitly configured nodes. Ma, et al. Expires 28 April 2022 [Page 8] Internet-Draft System-defined Configuration October 2021 This explicit configuration of system configuration in can be useful, for example, when an operator's workflow requires a client or offline tool to see the configuration as valid. The client can explicitly declare (i.e. configure in ) the list entries (with at least the keys) for any system configuration list entries that are referenced elsewhere in . The client does not necessarily need to declare all the contents of the list entry (i.e. the descendant nodes) - only the parts that are required to make the appear valid offline. 4.4. Examples The examples within this document use the fictional interface YANG module defined in Appendix C.3 of [RFC8342]. In addition, a fictional QoS data model example is provided. 4.4.1. Modifying A System-instantiated Leaf's Value In this subsection, we will use this fictional QoS data model: container qos-policies { list policy { key "name"; leaf name { type string; } list queue { key "queue-id"; description "Enter the queue list instance"; leaf queue-id { type int32 { range "1..32"; } } leaf maximum-burst-size { type int32 { range "0..100"; } } } } } Suppose a client creates a qos policy "my-policy" with 4 system instantiated queues(1~4). The Configuration of qos-policies is present in as follows: Ma, et al. Expires 28 April 2022 [Page 9] Internet-Draft System-defined Configuration October 2021 my-policy 1 50 2 60 3 70 4 80 A client modifies the value of maximum-burst-size to 55 in queue-id 1: my-policy 1 55 Then the configuration of qos-policies is present in as follows: Ma, et al. Expires 28 April 2022 [Page 10] Internet-Draft System-defined Configuration October 2021 my-policy 1 55 2 60 3 70 4 80 4.4.2. Configuring Descendant Nodes of A System-defined Node Suppose the system provides a loopback interface (named "lo0") with a default IPv4 address of "127.0.0.1" and a default IPv6 address of "::1". The configuration of "lo0" interface is present in as follows: lo0 127.0.0.1 ::1 The configuration of "lo0" interface is present in as follows: Ma, et al. Expires 28 April 2022 [Page 11] Internet-Draft System-defined Configuration October 2021 lo0 127.0.0.1 ::1 Later on, the client further configures the description node of a "lo0" interface as follows: lo0 loopback Then the configuration of interface "lo0" is present in as follows: lo0 loopback 127.0.0.1 ::1 Ma, et al. Expires 28 April 2022 [Page 12] Internet-Draft System-defined Configuration October 2021 4.4.3. Declaring A System-defined Node in Explicitly In the environment which offline validation of is required, a client need to declare the system-defined configurations that are actually referenced. Here is an example of a client explicitly declaring "lo0" in . The client configures a "lo0" interface only with the list key "name" as follows: lo0 A read-back of should looks like: lo0 5. Discovering System Configuration There are two ways to discover system configuration: a "with-system" query parameter and a configuration datastore. Ma, et al. Expires 28 April 2022 [Page 13] Internet-Draft System-defined Configuration October 2021 5.1. The "with-system" Query Parameter As defined in Section 1.3 and Section 1.4, All the system configuration will be implicitly hidden in , hence the client can retrieve them through standard operations defined in YANG- driven management protocols such as NETCONF and RESTCONF with a "with-system" parameter to get a merged view. All servers MUST implement a "with-system" parameter. 5.2. The Configuration Datastore This section is not applicable to non-NMDA servers. NMDA servers SHOULD implement a configuration datastore, and they SHOULD also implement the datastore, which can be used as an alternative to "with-system" parameter. Following guidelines for defining datastores in the appendix A of [RFC8342], this document introduces a new optional datastore resource named 'system' that represents the system configuration. A device MAY implement the mechanism defined in this document without implementing the "system" datastore, which would only eliminate the ability to programmatically determine the system configuration. * Name: "system" * YANG modules: all * YANG nodes: all "config true" data nodes * Management operations: The content of the datastore is set by the server in an implementation dependent manner. The content can not be changed by management operations via NETCONF, RESTCONF,the CLI, etc, but may change itself by upgrades and/or when resource- conditions are met. The datastore can be read using the standard NETCONF/RESTCONF protocol operations. * Origin: This document does not define any new origin identity when it interacts with datastore and finally flows into . The "system" origin Metadata Annotation [RFC7952] is used to indicate the origin of a data item. Comment: Should we define any new origin identity to indicate new source of system configuration datastore? * Protocols: YANG-driven management protocols, such as NETCONF and RESTCONF. Ma, et al. Expires 28 April 2022 [Page 14] Internet-Draft System-defined Configuration October 2021 * Defining YANG module: "ietf-system". The datastore's content is populated by the server and read-only to clients. Upon the content is created or changed, it will be merged into datastore. Unlike [RFC8808], it MAY change dynamically, e.g., depending on factors like during device upgrade or system-controlled resources(e.g., HW available) and the datastore does not have to persist across reboots. RPC operation defined in [RFC8088] can reset it to its factory default configuration without including configuration generated due to the system update or client-enabled functionality. 6. The "ietf-netconf-with-system" Module 6.1. Data Model Overview This YANG module augments NETCONF and operation, which is designed to make implicitly hidden system configuration visible via a "with-system" parameter. The following tree diagram [RFC8340] illustrates the "ietf-netconf- with-system" module: module: ietf-netconf-with-system augment /nc:get-config/nc:input: +---w with-system? empty augment /nc:get/nc:input: +---w with-system? empty The following tree diagram [RFC8340] illustrates "get" and "get- config" rpcs defined in "ietf-netconf" augmented by "ietf-netconf- with-system" module : Ma, et al. Expires 28 April 2022 [Page 15] Internet-Draft System-defined Configuration October 2021 rpcs: +---x get-config | +---w input | | +---w source | | | +---w (config-source) | | | +--:(candidate) | | | | +---w candidate? empty {candidate}? | | | +--:(running) | | | | +---w running? empty | | | +--:(startup) | | | +---w startup? empty {startup}? | | +---w filter? | | +---w with-system? empty | +--ro output | +--ro data? +---x get | +---w input | | +---w filter? | | +---w with-system? empty | +--ro output | +--ro data? 6.2. Example Usage This section gives an example of request/response pairs with and without the "with-system" query parameter. The YANG module used are shown in Appendix C.2 of [RFC8342]. Suppose the following data is added to : { "bgp": { "local-as": "64501", "peer-as": "64502", "peer": { "name": "2001:db8::2:3" } } } All the messages are presented in a protocol-independent manner. JSON is used only for its conciseness. REQUEST(without a "with-system" query parameter): Target:/bgp Query Parameter: with-defaults: report-all Ma, et al. Expires 28 April 2022 [Page 16] Internet-Draft System-defined Configuration October 2021 RESPONSE(both bgp/peer/local-as and bgp/peer/peer-as have default values for a peer. "local-port" leaf is not present in ): { "bgp": { "local-as": "64501", "peer-as": "64502", "peer": { "name": "2001:db8::2:3", "local-as": "64501", "peer-as": "64502", "remote-port": "179", "state": "established" } } } REQUEST(with a "with-system" query parameter): Target:/bgp Query Parameter: with-system with-defaults: report-all RESPONSE(local-port leaf value is supplied by the system): { "bgp": { "local-as": "64501", "peer-as": "64502", "peer": { "name": "2001:db8::2:3", "local-as": "64501", "peer-as": "64502", "local-port": "60794", "remote-port": "179", "state": "established" } } } 6.3. YANG Module Ma, et al. Expires 28 April 2022 [Page 17] Internet-Draft System-defined Configuration October 2021 file="ietf-netconf-with-system@2021-05-14.yang" module ietf-netconf-with-system { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-netconf-with-system"; prefix ncws; import ietf-netconf { prefix nc; reference "RFC 6241: Network Configuration Protocol (NETCONF)"; } organization "IETF NETMOD (Network Modeling) Working Group"; contact "WG Web: WG List: "; description "This module defines an extension to the NETCONF protocol that allows the NETCONF client to control how system configuration data are handled by the server in particular NETCONF operations. Copyright (c) 2010 IETF Trust and the persons identified as the document authors. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices."; // RFC Ed.: replace XXXX with actual RFC number and remove this note revision 2021-05-14 { description "Initial version."; reference "RFC XXXX: System configuration Data handling Behavior"; } augment /nc:get-config/nc:input { description " Allows the get-config operation to use with-system to retrieve the complete system configuration."; Ma, et al. Expires 28 April 2022 [Page 18] Internet-Draft System-defined Configuration October 2021 leaf with-system { type empty ; description "Support system configuration retrieval on conventional configuration datastore. "; } } augment /nc:get/nc:input { description " Allows the get operation to use with-system to retrieve the complete system configuration."; leaf with-system { type empty ; description "Support system configuration retrieval on running datastore."; } } } 7. The "ietf-system-datastore" Module 7.1. Data Model Overview This YANG module defines a new YANG identity named "system" that uses the "ds:datastore" identity defined in [RFC8342]. Note that no new origin identity is defined in this document, the "or:system" origin Metadata Annotation [RFC7952] is used to indicate the origin of a data item. The following diagram illustrates the relationship amongst the "identity" statements defined in the "ietf-system-datastore" and "ietf-datastores" YANG modules Identities: +--- datastore | +--- conventional | | +--- running | | +--- candidate | | +--- startup | | +--- system | | +--- intended | +--- dynamic | +--- operational The diagram above uses syntax that is similar to but not defined in [RFC8340]. Ma, et al. Expires 28 April 2022 [Page 19] Internet-Draft System-defined Configuration October 2021 7.2. Example Usage This section gives an example of data retrieval from . Suppose the following data is added to : { "bgp": { "local-as": "64501", "peer-as": "64502", "peer": { "name": "2001:db8::2:3" } } } All the messages are presented in a protocol-independent manner. JSON is used only for its conciseness. REQUEST: Datastore: Target:/bgp RESPONSE("local-port" leaf value is supplied by the system): { "bgp": { "peer": { "local-port": "60794" } } } 7.3. YANG Module file="ietf-system-datastore@2021-05-14.yang" module ietf-system-datastore { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-system-datastore"; prefix sysds; import ietf-datastores { prefix ds; reference "RFC 8342: Network Management Datastore Architecture(NMDA)"; } Ma, et al. Expires 28 April 2022 [Page 20] Internet-Draft System-defined Configuration October 2021 organization "IETF NETMDOD (Network Modeling) Working Group"; contact "WG Web: WG List: "; description "This module defines a new YANG identity that uses the ds:datastore identity defined in [RFC8342]. Copyright (c) 2010 IETF Trust and the persons identified as the document authors. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices."; // RFC Ed.: replace XXXX with actual RFC number and remove this note revision 2021-05-14 { description "Initial version."; reference "RFC XXXX: System configuration Data handling Behavior"; } identity system { base ds:conventional; description "This read-only datastore contains the complete configuration provided by the system itself."; } } 8. IANA Considerations 8.1. The "IETF XML" Registry This document registers two XML namespace URNs in the 'IETF XML registry', following the format defined in [RFC3688]. Ma, et al. Expires 28 April 2022 [Page 21] Internet-Draft System-defined Configuration October 2021 URI: urn:ietf:params:xml:ns:yang:ietf-netconf-with-system Registrant Contact: The IESG. XML: N/A, the requested URIs are XML namespaces. URI: urn:ietf:params:xml:ns:yang:ietf-system-datastore Registrant Contact: The IESG. XML: N/A, the requested URIs are XML namespaces. 8.2. The "YANG Module Names" Registry This document registers one module name in the 'YANG Module Names' registry, defined in [RFC6020] . name: ietf-netconf-with-system prefix: ncws namespace: urn:ietf:params:xml:ns:yang:ietf-netconf-with-system RFC: XXXX // RFC Ed.: replace XXXX and remove this comment name: ietf-system-datastore prefix: sys namespace: urn:ietf:params:xml:ns:yang:ietf-system-datatstore RFC: XXXX // RFC Ed.: replace XXXX and remove this comment 9. Security Considerations 9.1. Regarding the "ietf-netconf-with-system" YANG Module The YANG module defined in this document extends the base operations for NETCONF [RFC6241] and RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC8446]. The Network Configuration Access Control Model (NACM) [RFC8341] provides the means to restrict access for particular NETCONF users to a preconfigured subset of all available NETCONF protocol operations and content. The security considerations for the base NETCONF protocol operations (see Section 9 of [RFC6241] apply to the new extended RPC operations defined in this document. Ma, et al. Expires 28 April 2022 [Page 22] Internet-Draft System-defined Configuration October 2021 9.2. Regarding the "ietf-system-datastore" YANG Module The YANG module defined in this document extends the base operations for NETCONF [RFC6241] and RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC8446]. The Network Configuration Access Control Model (NACM) [RFC8341] provides the means to restrict access for particular NETCONF users to a preconfigured subset of all available NETCONF protocol operations and content. 10. Contributors Chongfeng Xie China Telecom Beijing China Email: xiechf@chinatelecom.cn Kent Watsen Watsen Networks Email: kent+ietf@watsen.net Jason Sterne Nokia Email: jason.sterne@nokia.com Acknowledgements Thanks to Robert Wilton, Balazs Lengyel, Andy Bierman, Jan Lindbland, Juergen Schoenwaelder, Alex Clemm, Timothy Carey for reviewing, and providing important input to, this document. References Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . Ma, et al. Expires 28 April 2022 [Page 23] Internet-Draft System-defined Configuration October 2021 Informative References [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K., and R. Wilton, "Network Management Datastore Architecture (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018, . [RFC8407] Bierman, A., "Guidelines for Authors and Reviewers of Documents Containing YANG Data Models", BCP 216, RFC 8407, DOI 10.17487/RFC8407, October 2018, . [RFC8525] Bierman, A., Bjorklund, M., Schoenwaelder, J., Watsen, K., and R. Wilton, "YANG Library", RFC 8525, DOI 10.17487/RFC8525, March 2019, . [RFC8808] Wu, Q., Lengyel, B., and Y. Niu, "A YANG Data Model for Factory Default Settings", RFC 8808, DOI 10.17487/RFC8808, August 2020, . Appendix A. Key Use Cases Following provides three use cases related to system-defined configuration lifecycle management. The simple interface data model defined in Appendix C.3 of [RFC8342] is used. For each use case, snippets of , , and are shown. A.1. Device Powers On : No configuration for “lo0” appears in ; Ma, et al. Expires 28 April 2022 [Page 24] Internet-Draft System-defined Configuration October 2021 : lo0 127.0.0.1 ::1 : lo0 127.0.0.1 ::1 : lo0 127.0.0.1 ::1 A.2. Client Commits Configuration If a client creates an interface "et-0/0/0" but the interface does not physically exist at this point: : et-0/0/0 Test interface : Ma, et al. Expires 28 April 2022 [Page 25] Internet-Draft System-defined Configuration October 2021 lo0 127.0.0.1 ::1 : lo0 127.0.0.1 ::1 et-0/0/0 Test interface : lo0 127.0.0.1 ::1 A.3. Operator Installs Card into a Chassis : et-0/0/0 Test interface : Ma, et al. Expires 28 April 2022 [Page 26] Internet-Draft System-defined Configuration October 2021 lo0 127.0.0.1 ::1 et-0/0/0 1500 : lo0 127.0.0.1 ::1 et-0/0/0 Test interface 1500 : lo0 127.0.0.1 ::1 et-0/0/0 Test interface 1500 Appendix B. Changes between Revisions v02 - v00 Ma, et al. Expires 28 April 2022 [Page 27] Internet-Draft System-defined Configuration October 2021 * Restructure the document content based on input in the system defined configuration interim meeting. * Updates NMDA to define a read-only conventional configuration datastore called "system". * Retrieval of implicit hidden system configuration via with "with-system" parameter to support non-NMDA servers. * Provide system defined configuration classification. * Define Static Characteristics and dynamic behavior for system defined configuration. * Separate "ietf-system-datastore" Module from "ietf-netconf-with- system" Module. * Provide usage examples for dynamic behaviors. * Provide usage examples for two YANG modules. * Provide three use cases related to system-defined configuration lifecycle management. * Classify the relation with . Appendix C. Open Issues tracking * Backward compatibility:consider the communication between the server and the new client or the old client simultaneously. * Running always be valid? The client might need to understand how to merge if offline validation on running is used. * Immutable flag Authors' Addresses Qiufang Ma (editor) Huawei 101 Software Avenue, Yuhua District Nanjing Jiangsu, 210012 China Email: maqiufang1@huawei.com Ma, et al. Expires 28 April 2022 [Page 28] Internet-Draft System-defined Configuration October 2021 Feng Chong Huawei 101 Software Avenue, Yuhua District Nanjing Jiangsu, 210012 China Email: frank.fengchong@huawei.com Qin Wu Huawei 101 Software Avenue, Yuhua District Nanjing Jiangsu, 210012 China Email: bill.wu@huawei.com Ma, et al. Expires 28 April 2022 [Page 29]