ietf-immutable.yang

module ietf-immutable {
  yang-version 1.1;
  namespace "urn:ietf:params:xml:ns:yang:ietf-immutable";
  prefix im;

  import ietf-yang-metadata {
    prefix md;
  }
  import ietf-netconf {
    prefix nc;
    reference
      "RFC 6241: Network Configuration Protocol (NETCONF)";
  }
  import ietf-netconf-nmda {
    prefix ncds;
    reference
      "RFC 8526: NETCONF Extensions to Support the Network
       Management Datastore Architecture";
  }
  organization
    "IETF Network Modeling (NETMOD) Working Group";

  contact
    "WG Web: <https://datatracker.ietf.org/wg/netmod/>
     WG List: <mailto:netmod@ietf.org>
     Author: Qiufang Ma
             <mailto:maqiufang1@huawei.com>
     Author: Qin Wu
             <mailto:bill.wu@huawei.com>
     Author: Balazs Lengyel
             <mailto:balazs.lengyel@ericsson.com>
     Author: Hongwei Li
             <mailto:flycoolman@gmail.com>";

  description
    "This module defines a metadata annotation called 'immutable'
     to allow the server to formally document existing behavior on
     the mutability of some system configuration. Clients may use
     'immutable' metadata annotation provided by the server to know
     beforehand why certain otherwise valid configuration requests
     will cause the server to return an error.

     Copyright (c) 2024 IETF Trust and the persons identified
     as authors of the code. 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 Revised
     BSD License set forth in Section 4.c of the IETF Trust's
     Legal Provisions Relating to IETF Documents
     (https://trustee.ietf.org/license-info).

     This version of this YANG module is part of RFC HHHH
     (https://www.rfc-editor.org/info/rfcHHHH); see the RFC
     itself for full legal notices.

     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 (RFC 2119)
     (RFC 8174) when, and only when, they appear in all
     capitals, as shown here.";

  revision 2024-06-04 {
    description
      "Initial revision.";
    // RFC Ed.: replace XXXX and remove this comment
    reference
      "RFC XXXX: YANG Metadata Annotation for Immutable Flag";
  }

  md:annotation immutable {
    type boolean;
    description
      "The 'immutable' metadata annotation indicates the
       immutability of an instantiated data node. It takes as a
       value 'true' or 'false'. If the 'immutable' metadata
       annotation is not specified, the default value is the
       same as the value of its parent node in the data tree. The
       default value for a top-level instance node is false if not
       specified.";
  }

  feature immutable {
    description
      "Indicates that the server supports the 'immutable' metadata
       annotation.";
  }
  
  grouping with-immutable-grouping {
    description
      "Grouping for the with-immutable parameter that augments the
       RPC operations.";
    leaf with-immutable {
      type empty;
      description
        "If this parameter is present, the server returns the
         'immutable' annotation for configuration that it
         internally thinks immutable.";
    }
  }
  augment "/ncds:get-data/ncds:input" {
    if-feature "immutable";
    description
      "Allows the server to include 'immutable' metadata
       annotations in its response to get-data operation.";
    uses with-immutable-grouping;
  }
  augment "/nc:get-config/nc:input" {
    if-feature "immutable";
    description
      "Allows the server to include 'immutable' metadata
       annotations in its response to get-config operation.";
    uses with-immutable-grouping;
  }
  augment "/nc:get/nc:input" {
    if-feature "immutable";
    description
      "Allows the server to include 'immutable' metadata
       annotations in its response to get operation.";
    uses with-immutable-grouping;
  }
}