Network Working Group J. Clarke Internet-Draft B. Claise Intended status: Standards Track Cisco Systems, Inc. Expires: October 5, 2018 April 3, 2018 YANG module for yangcatalog.org draft-clacla-netmod-model-catalog-03 Abstract This document specifies a YANG module that contains metadata related to YANG modules and vendor implementations of those YANG modules. 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 October 5, 2018. Copyright Notice Copyright (c) 2018 IETF Trust and the persons identified as the document authors. All rights reserved. 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. Clarke & Claise Expires October 5, 2018 [Page 1] Internet-Draft YANG Catalog April 2018 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Status of Work and Open Issues . . . . . . . . . . . . . 3 2. Learning from Experience . . . . . . . . . . . . . . . . . . 3 2.1. YANG Module Library . . . . . . . . . . . . . . . . . . . 4 2.2. YANG Catalog Data Model . . . . . . . . . . . . . . . . . 4 2.3. Module Sub-Tree . . . . . . . . . . . . . . . . . . . . . 6 2.4. Compilation Information . . . . . . . . . . . . . . . . . 8 2.5. Maturity Level . . . . . . . . . . . . . . . . . . . . . 10 2.6. Generated From . . . . . . . . . . . . . . . . . . . . . 11 2.7. Implementation . . . . . . . . . . . . . . . . . . . . . 11 2.8. Vendor Sub-Tree . . . . . . . . . . . . . . . . . . . . . 12 2.9. Regex Expression Differences . . . . . . . . . . . . . . 13 3. YANG Catalog Use Cases . . . . . . . . . . . . . . . . . . . 14 3.1. YANG Search Metadata . . . . . . . . . . . . . . . . . . 14 3.2. Identify YANG Module Support in Devices . . . . . . . . . 14 3.3. Identify The Backward Compatibility between YANG Module Revisions . . . . . . . . . . . . . . . . . . . . . . . . 14 4. YANG Catalog YANG module . . . . . . . . . . . . . . . . . . 17 5. Security Considerations . . . . . . . . . . . . . . . . . . . 35 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 35 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 35 7.1. Normative References . . . . . . . . . . . . . . . . . . 35 7.2. Informative References . . . . . . . . . . . . . . . . . 36 7.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . 36 Appendix B. Changes From Previous Revisions . . . . . . . . . . 37 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 38 1. Introduction YANG [RFC6020] [RFC7950] became the standard data modeling language of choice. Not only is it used by the IETF for specifying models, but also in many Standard Development Organizations (SDOs), consortia, and open-source projects: the IEEE, the Broadband Forum (BFF), DMTF, MEF, ITU, OpenDaylight, Open ROADM, Openconfig, sysrepo, and more. With the rise of data model-driven management and the success of YANG as a key piece comes a challenge: the entire industry develops YANG models. In order for operators to automate coherent services, the industry must ensure the following: 1. Data models must work together 2. There exists a toolchain to help one search and understand models Clarke & Claise Expires October 5, 2018 [Page 2] Internet-Draft YANG Catalog April 2018 3. Metadata is present to further describe model attributes The site (and the YANG catalog that it provides) is an attempt to address these key tenants. From a high level point of view, the goal of this catalog is to become a reference for all YANG modules available in the industry, for both YANG developers (to search on what exists already) and for operators (to discover the more mature YANG models to automate services). This YANG catalog should not only contain pointers to the YANG modules themselves, but also contain metadata related to those YANG modules: What is the module type (service model or not?); what is the maturity level? (e.g., for the IETF: is this an RFC, a working group document or an individual draft?); is this module implemented?; who is the contact?; is there open-source code available? And we expect many more in the future. The industry has begun to understand that the metadata related to YANG models become equally important as the YANG models themselves. This document defines a YANG [RFC7950] module called yang- catalog.yang that contains the metadata definitions that are complementary to the related YANG modules themselves. The design for this module is based on experience and real code. As such, it's expected that this YANG module will be a living document. Furthermore, new use cases, which require new metadata in this YANG module, are discovered on a regular basis. The yangcatalog.org instantiation of the catalog provides a means for module authors and vendors implementing modules to upload their metadata, which is then searchable via an API, as well as using a variety of web-based tools. The instructions for contributing and searching for metadata can be found at . 1.1. Status of Work and Open Issues The top open issues are: 1. Obtain feedback from vendors and SDOs 2. Socialize module at the IETF and incorporate feedback 3. Provide module bundle support 2. Learning from Experience While implementing the catalog and tools at yangcatalog.org, we initially looked at the "Catalog and registry for YANG models" [I-D.openconfig-netmod-model-catalog] as a starting point but we Clarke & Claise Expires October 5, 2018 [Page 3] Internet-Draft YANG Catalog April 2018 quickly realized that the objectives are different. As a consequence, even if some of the information is similar, this YANG module started to diverge. Below are the justifications for the divergence, our observations, and our learning experience as we have been developing and getting feedback. 2.1. YANG Module Library In order for the YANG catalog to become a complete inventory of which models are supported on the different platforms, content such as the support of the YANG module/deviation/feature/etc. should be easy to import and update. An easy way to populate this information is to have a similar structure as the YANG Module Library [RFC7895]. That way, querying the YANG Module Library from a platform provides, directly in the right format, the input for the YANG catalog inventory. There are some similar entries between the YANG Module Library and the Openconfig catalog. For example, the Openconfig catalog model defines a "uri" leaf which is similar to "schema" from [RFC7895]). And this adds to the overall confusion. 2.2. YANG Catalog Data Model The structure of the yang-catalog.yang module described in this document is found below. The meaning of the symbols in this and seubsequent tree diagrams in this document is explained in [I-D.ietf-netmod-yang-tree-diagrams]: module: yang-catalog +--rw catalog +--rw modules | +--rw module* [name revision organization] | +--rw name yang:yang-identifier | +--rw revision union | +--rw organization string | +--rw ietf | | +--rw ietf-wg? string | +--rw namespace inet:uri | +--rw schema? inet:uri | +--rw generated-from? enumeration | +--rw maturity-level? enumeration | +--rw document-name? string | +--rw author-email? yc:email-address | +--rw reference? inet:uri | +--rw module-classification enumeration | +--rw compilation-status? enumeration | +--rw compilation-result? inet:uri Clarke & Claise Expires October 5, 2018 [Page 4] Internet-Draft YANG Catalog April 2018 | +--rw prefix? string | +--rw yang-version? enumeration | +--rw description? string | +--rw contact? string | +--rw module-type? enumeration | +--rw belongs-to? yang:yang-identifier | +--rw tree-type? enumeration | +--rw yang-tree? inet:uri | +--rw expires? yang:date-and-time | +--rw expired? union | +--rw submodule* [name revision] | | +--rw name yang:yang-identifier | | +--rw revision union | | +--rw schema? inet:uri | +--rw dependencies* [name] | | +--rw name yang:yang-identifier | | +--rw revision? union | | +--rw schema? inet:uri | +--rw dependents* [name] | | +--rw name yang:yang-identifier | | +--rw revision? union | | +--rw schema? inet:uri | +--rw semantic-version? yc:semver | +--rw derived-semantic-version? yc:semver | +--rw implementations | +--rw implementation* [vendor platform software-version software-flavor] | +--rw vendor string | +--rw platform string | +--rw software-version string | +--rw software-flavor string | +--rw os-version? string | +--rw feature-set? string | +--rw os-type? string | +--rw feature* yang:yang-identifier | +--rw deviation* [name revision] | | +--rw name yang:yang-identifier | | +--rw revision union | +--rw conformance-type? enumeration +--rw vendors +--rw vendor* [name] +--rw name string +--rw platforms +--rw platform* [name] +--rw name string +--rw software-versions +--rw software-version* [name] +--rw name string +--rw software-flavors Clarke & Claise Expires October 5, 2018 [Page 5] Internet-Draft YANG Catalog April 2018 +--rw software-flavor* [name] +--rw name string +--rw protocols | +--rw protocol* [name] | +--rw name identityref | +--rw protocol-version* string | +--rw capabilities* string +--rw modules +--rw module* [name revision organization] +--rw name -> /catalog/modules/module/name +--rw revision -> deref(../name)/../revision +--rw organization -> deref(../revision)/../organization +--rw os-version? string +--rw feature-set? string +--rw os-type? string +--rw feature* yang:yang-identifier +--rw deviation* [name revision] | +--rw name yang:yang-identifier | +--rw revision union +--rw conformance-type? enumeration Various elements of this module tree will be discussed in the subsequent sections. 2.3. Module Sub-Tree Each module in the YANG Catalog is enumerated by its metadata and by various vendor implementations. While initially each module used the "module-list" grouping from the YANG Library [RFC7895], it was found that some of the nodes within that grouping such as "conformance- type", "feature", and "deviation" are only valid when a module is implemented by a server. As pure YANG data (which the Catalog is) it is not possible to provide meaningful values for those nodes. As such, common leafs were extracted from the YANG Library's "module- list" for use in the module sub-tree of yang-catalog. Those server- specific nodes are moved under the implementation sub-tree. The yang-catalog module then augments these common nodes to add metadata elements that aid module developers and module consumers alike in understanding the relative maturity, compilation status, and the support contact(s) of each YANG module. +--rw modules | +--rw module* [name revision organization] | +--rw name yang:yang-identifier | +--rw revision union | +--rw organization string | +--rw ietf | | +--rw ietf-wg? string Clarke & Claise Expires October 5, 2018 [Page 6] Internet-Draft YANG Catalog April 2018 | +--rw namespace inet:uri | +--rw schema? inet:uri | +--rw generated-from? enumeration | +--rw maturity-level? enumeration | +--rw document-name? string | +--rw author-email? yc:email-address | +--rw reference? inet:uri | +--rw module-classification enumeration | +--rw compilation-status? enumeration | +--rw compilation-result? inet:uri | +--rw prefix? string | +--rw yang-version? enumeration | +--rw description? string | +--rw contact? string | +--rw module-type? enumeration | +--rw belongs-to? yang:yang-identifier | +--rw tree-type? enumeration | +--rw yang-tree? inet:uri | +--rw expires? yang:date-and-time | +--rw expired? union | +--rw submodule* [name revision] | | +--rw name yang:yang-identifier | | +--rw revision union | | +--rw schema? inet:uri | +--rw dependencies* [name] | | +--rw name yang:yang-identifier | | +--rw revision? union | | +--rw schema? inet:uri | +--rw dependents* [name] | | +--rw name yang:yang-identifier | | +--rw revision? union | | +--rw schema? inet:uri | +--rw implementations | +--rw implementation* | [vendor platform software-version software-flavor] | +--rw vendor string | +--rw platform string | +--rw software-version string | +--rw software-flavor string | +--rw os-version? string | +--rw feature-set? string | +--rw os-type? string | +--rw feature* yang:yang-identifier | +--rw deviation* [name revision] | | +--rw name yang:yang-identifier | | +--rw revision union | +--rw conformance-type? enumeration Clarke & Claise Expires October 5, 2018 [Page 7] Internet-Draft YANG Catalog April 2018 Many of these additional metadata fields are self-explanatory, especially given their descriptions in the module itself and the fact that many elements translate directly to YANG schema elements. However, those requiring additional explanation or context as to why they are needed are described in the subsequent sections. 2.4. Compilation Information For the inventory to be complete, YANG modules at different stages of their lifecyle should be taken into account, including YANG modules that are clearly works-in-progress (i.e., that do not validate correctly either because of faulty YANG constructs, because of a faulty imported YANG module, or simply because of warnings). The results of compilation testing are denoted in the "compilation- status" leaf with links to the output of the tests stored in the "compilation-result" leaf. Note that some warnings seen in "compilation-result" are not always show-stoppers from a code generation point of view (see the Generated From section). Nonetheless, the compilation or validation status, along with the compilation output, provide a clear indication of a given YANG module's development phase and stability. The current set of validator is pyang, confdc, yangdump-pro, and yanglint. Clarke & Claise Expires October 5, 2018 [Page 8] Internet-Draft YANG Catalog April 2018 leaf compilation-status { type enumeration { enum passed { description "All compilers were able to compile this YANG module without any errors or warnings."; } enum passed-with-warnings { description "All compilers were able to compile this YANG module without any errors, but at least one of them caught a warning."; } enum failed { description "At least one of compilers found an error while compiling this YANG module."; } enum pending { description "The module was just added to the catalog and compilation testing is still in progress."; } enum unknown { description "There is not sufficient information about compilation status. This Could mean compilation crashed causing it not to complete fully."; } } description "Status of the module, whether it was possible to compile this YANG module or there are still some errors/warnings."; } leaf compilation-result { type string; description "Result of the compilation explaining specifically what error or warning occurred. This is not existing if compilation status is PASSED."; } The current instantiation of the YANG Catalog at uses a number of different YANG compilers for testing. The wrapper that handles validation attempts to use metadata from the catalog to determine which tests to perform on a given module. For example, if the module is authored by the IETF, IETF-specific tests will be conducted to provide the most accurate and complete set of tests possible. Clarke & Claise Expires October 5, 2018 [Page 9] Internet-Draft YANG Catalog April 2018 2.5. Maturity Level Models also have inherent maturity levels from their respective Standards Development Organizations (SDOs). These maturity levels help module consumers understand how complete, tested, etc. a module is. leaf maturity-level { type enumeration { enum ratified { description "Maturity of a module that is fully approved (e.g., a standard)."; } enum adopted { description "Maturity of a module that is actively being developed by a organization towards ratification."; } enum initial { description "Maturity of a module that has been initially created, but has no official organization-level status."; } enum not-applicable { description "The maturity level is not used for vendor-supplied models, and thus all vendor modules will have a maturity of not-applicable"; } } description "The current maturity of the module with respect to the body that created it. This allows one to understand where the module is in its overall life cycle."; } This enumeration mapping has been implemented for the YANG modules from IETF and BBF. The "maturity-level" MUST be "not-applicable" for all vendor-authored modules. In addition to a module's maturity, modules that are part of works- in-progress (e.g., IETF internet drafts) may expire if work ceases on the related document. To track that, the catalog has two module leafs: "expires" and "expired". The "expires" leaf indicates a date and time when the module is expected to expire whereas the "expired" leaf indicates whether or not the module has already expired. For those modules that will never expire, the "expired" leaf MUST be set to "not-applicable". Clarke & Claise Expires October 5, 2018 [Page 10] Internet-Draft YANG Catalog April 2018 2.6. Generated From While many models are written by hand (i.e., authored by humans) others are generated from things such as vendor code or CLI constructs or from SMI-based MIB modules. These "generated" modules do not necessarily require the same stringent validity checking that hand-written modules require. As such, these modules have a generated-from value that is designed to inform validators how much checking to do. leaf generated-from { type enumeration { enum "mib" { description "Module generated from Structure of Management Information (SMI) MIB per RFC6643."; } enum "not-applicable" { description "Module was not generated but it was authored manually."; } enum "native" { description "Module generated from platform internal, proprietary structure, or code."; } } default "not-applicable"; description "This statement defines weather the module was generated or not. Default value is set to not-applicable, which means that module was created manualy and not generated."; } 2.7. Implementation As of version 02 of openconfig-model-catalog.yang [I-D.openconfig-netmod-model-catalog] it is not possible to identify the implementations of one specific module. Instead modules are grouped into feature-bundle, and feature-bundles are implemented by devices. Because of this, we added our own implementation sub-tree under each module to yang-catalog.yang. Our implementation sub-tree is: Clarke & Claise Expires October 5, 2018 [Page 11] Internet-Draft YANG Catalog April 2018 +--rw implementation* [vendor platform software-version software-flavor] +--rw vendor string +--rw platform string +--rw software-version string +--rw software-flavor string +--rw os-version? string +--rw feature-set? string +--rw os-type? string +--rw feature* yang:yang-identifier +--rw deviation* [name revision] | +--rw name yang:yang-identifier | +--rw revision union +--rw conformance-type? enumeration The keys in this sub-tree can be used in the "vendor" sub-tree defined below to walk through each vendor, platform, and software release to get a full list of supported YANG modules for that release. The "software-flavor" key leaf identifies a variation of a specific version where YANG model support may be different. Depending on the vendor, this could be a license, additional software component, or a feature set. The other non-key leaves in the implementation sub-tree represent optional elements of a software release that some vendors may choose to use for informational purposes. These leafs are duplicated under the vendor sub-tree. 2.8. Vendor Sub-Tree The vendor sub-tree provides a way, especially for module consumers, to walk through a specific device and software release to find a list of modules supported therein. This sub-tree turns the "implementation" sub-tree on its head to provide an optimized index for one wanting to go from a platform to a full list of modules. In addition to the module list, the vendor sub-tree lists the YANG- based protocols (e.g., NETCONF or RESTCONF) that the platforms support. Clarke & Claise Expires October 5, 2018 [Page 12] Internet-Draft YANG Catalog April 2018 +--rw vendors +--rw vendor* [name] +--rw name string +--rw platforms +--rw platform* [name] +--rw name string +--rw software-versions +--rw software-version* [name] +--rw name string +--rw software-flavors +--rw software-flavor* [name] +--rw name string +--rw protocols | +--rw protocol* [name] | +--rw name identityref | +--rw protocol-version* string | +--rw capabilities* string +--rw modules +--rw module* [name revision organization] +--rw name leafref +--rw revision leafref +--rw organization leafref +--rw os-version? string +--rw feature-set? string +--rw os-type? string +--rw feature* | yang:yang-identifier +--rw deviation* [name revision] | +--rw name | | yang:yang-identifier | +--rw revision union +--rw conformance-type? enumeration This sub-tree structure also enables one to look for YANG modules for a class of platforms (e.g., list of modules for Cisco, or list of modules for Cisco ASR9K routers) instead of only being able to look for YANG modules for a specific platform and software release. 2.9. Regex Expression Differences Another challenge encountered when trying to using [I-D.openconfig-netmod-model-catalog] as the canonical catalog is the regular expression syntax it uses. The Openconfig module uses a POSIX-compliant regular expression syntax whereas YANG-based protocol implementations like ConfD [1] expect the IETF-chosen W3C syntax. In order to load the Openconfig catalog in such engines, changes to the Clarke & Claise Expires October 5, 2018 [Page 13] Internet-Draft YANG Catalog April 2018 regular expression syntax had to be done, and these one-off changes are not supportable. 3. YANG Catalog Use Cases The YANG Catalog module is currently targeted to address the following use cases. 3.1. YANG Search Metadata The yangcatalog.org toolchain provides a service for searching [2] for YANG modules based on keywords. The resulting search data currently stores the module and node metadata in a proprietary format along with the search index data. By populating the yang-catalog module, this search service can instead pull the metadata from the implementation of the module. Populating this instance of the yang- catalog module will be using an API that is still under development, but will ultimately allow SDOs and vendors to provide metadata and ensure the search service has the most up-to-date data for all available modules. 3.2. Identify YANG Module Support in Devices By organizing the yang-catalog module so that one can either find all implementations for a given module, or find all modules supported by a vendor platform and software release, the catalog will provide a straight-forward way for one to understand the extent of YANG module support in participating vendors' software releases. Eventually a web-based graphical interface will be connected to this on yangcatalog.org to make it easier for consumers to leverage the instance of the yang-catalog module for this use case. 3.3. Identify The Backward Compatibility between YANG Module Revisions The YANG catalog contains not only the most up-to-date YANG module revision of a given module, but keeps all previous revisions as well. With APIs in mind, it's important to understand whether different YANG module revisions are backward compatible (this is specifically imported for native YANG modules, i.e. the ones where generated-from = native). This document uses the following semver.org semantic [semver] to compare the YANG module backwards (in)compatibility: MAJOR is incremented when the new version of the specification is incompatible with previous versions. MINOR is incremented when new functionality is added in a manner that is backward-compatible with previous versions. Clarke & Claise Expires October 5, 2018 [Page 14] Internet-Draft YANG Catalog April 2018 PATCH is incremented when bug fixes are made in a backward- compatible manner. Two distinct leaves in the YANG module contains this semver semantic: the semantic-version leaf contains the value reported as metadata by a specific YANG module. the derived-semantic-version leaf is established by examining the the YANG module themselves. As such, only the YANG syntax, as opposed to the implementation changes that lead some some semantic changes. Typically, an Openconfig YANG module would contain an extension, which is mapped to the semantic-version leaf. Clarke & Claise Expires October 5, 2018 [Page 15] Internet-Draft YANG Catalog April 2018 // extension statements extension openconfig-version { argument "semver" { yin-element false; } description "The OpenConfig version number for the module. This is expressed as a semantic version number of the form: x.y.z where: * x corresponds to the major version, * y corresponds to a minor version, * z corresponds to a patch version. This version corresponds to the model file within which it is defined, and does not cover the whole set of OpenConfig models. Where several modules are used to build up a single block of functionality, the same module version is specified across each file that makes up the module. A major version number of 0 indicates that this model is still in development (whether within OpenConfig or with industry partners), and is potentially subject to change. Following a release of major version 1, all modules will increment major revision number where backwards incompatible changes to the model are made. The minor version is changed when features are added to the model that do not impact current clients use of the model. The patch-level version is incremented when non-feature changes (such as bugfixes or clarifications to human-readable descriptions that do not impact model functionality) are made that maintain backwards compatibility. The version number is stored in the module meta-data."; } Note that the absolute numbers in the semantic-version and derived- semantic-version are actually meaningless: the difference between two YANG module semver fields should be looked at. In addition to the semantic versions, the yang-tree field points to the respective module's simplified graphical representation of its model as described by [I-D.ietf-netmod-yang-tree-diagrams]. This diagram can be compared between two revisions of the same module to visually determine any structural differences when MAJOR or MINOR semantic versions differ. Clarke & Claise Expires October 5, 2018 [Page 16] Internet-Draft YANG Catalog April 2018 4. YANG Catalog YANG module The structure of the model defined in this document is described by the YANG module below. file "yang-catalog@2018-04-03.yang" module yang-catalog { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:yang-catalog"; prefix yc; import ietf-yang-types { prefix yang; } import ietf-yang-library { prefix yanglib; } import ietf-inet-types { prefix inet; } organization "yangcatalog.org"; contact "Benoit Claise Joe Clarke "; description "This module contains metadata pertinent to each YANG module, as well as a list of vendor implementations for each module. The structure is laid out in such a way as to make it possible to locate metadata and vendor implementation on a per-module basis as well as obtain a list of available modules for a given vendor's platform and specific software release."; revision 2018-04-03 { description "Bump the YANG version number to 1.1 for the deref XPath function."; reference "YANG Catalog "; } revision 2018-01-23 { description "* Add leafs to track expire modules * Correct a bug with leafref dereferencing"; reference "YANG Catalog "; } revision 2017-09-26 { Clarke & Claise Expires October 5, 2018 [Page 17] Internet-Draft YANG Catalog April 2018 description "* Add leafs for tracking dependencies and dependents * Simplify the generated-from enumerated values * Refine the type for compilation-result to be an inet:uri * Add leafs for semantic versioning"; reference "YANG Catalog "; } revision 2017-08-18 { description "* Reorder organization to be with the other module keys * Add a belongs-to leaf to track a submodule's parent"; reference "YANG Catalog "; } revision 2017-07-28 { description "* Revert config false nodes as we need to be able to set these via * Make conformance-type optional as not all vendors implement yang-library * Re-add the path typedef"; reference "YANG Catalog "; } revision 2017-07-26 { description "A number of improvements based on YANG Doctor review: * Remove references to 'server' in leafs describing YANG data * Fold the augmentation module leafs directly under /catalog/modules/module * Use identities for protocols instead of an emumeration * Make some extractable fields 'config false' * Fix various types * Normalize enums to be lowercase * Add a leaf for module-classification * Change yang-version to be an enum * Add module conformance, deviation and feature leafs under the implementation branches"; reference "YANG Catalog "; } revision 2017-07-14 { description "Modularize some of the leafs and create typedefs so they can be shared between the API input modules."; reference "YANG Catalog "; } revision 2017-07-03 { description "Initial revision."; reference " Clarke & Claise Expires October 5, 2018 [Page 18] Internet-Draft YANG Catalog April 2018 YANG Catalog "; } /* * Identities */ identity protocol { description "Abstract base identity for a YANG-based protocol."; } identity netconf { base protocol; description "Protocol identity for NETCONF as described in RFC 6241."; } identity restconf { base protocol; description "Protocol identity for RESTCONF as described in RFC 8040."; } typedef email-address { type string { pattern "[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9-]+([.][a-zA-Z0-9-]+)*"; } description "This type represents a string with an email address."; } /* * Typedefs */ typedef path { type string { pattern '([A-Za-z]:|[\w-]+(\.[\w-]+)*)?(([/\\][\w@.-]+)+)'; } description "This type represents a string with path to the file."; } typedef semver { type string { pattern '[0-9]+\.[0-9]+\.[0-9]+'; } Clarke & Claise Expires October 5, 2018 [Page 19] Internet-Draft YANG Catalog April 2018 description "A semantic version in the format of x.y.z, where: x = the major version number y = the minor version number z = the patch version number Changes to the major version number denote backwards-incompatible changes between two revisions of the same module. Changes to the minor version number indicate there have been new backwards-compatible features introduced in the later version of a module. Changes to the patch version indicate bug fixes between two versions of a module."; reference "Semantic Versioning 2.0.0 "; } container catalog { description "Root container of yang-catalog holding two main branches - modules and vendors. The modules sub-tree contains all the modules in the catalog and all of their metadata with their implementations. The vendor sub-tree holds modules for specific vendors, platforms, software-versions, and software-flavors. It contains reference to a name and revision of the module in order to reference the module's full set of metadata."; container modules { description "Container holding the list of modules"; list module { key "name revision organization"; description "Each entry represents one revision of one module for one organization."; uses yang-lib-common-leafs; leaf organization { type string; description "This statement defines the party responsible for this module. The argument is a string that is used to specify a textual description of the organization(s) under whose auspices this module was developed."; } uses organization-specific-metadata; leaf namespace { type inet:uri; Clarke & Claise Expires October 5, 2018 [Page 20] Internet-Draft YANG Catalog April 2018 mandatory true; description "The XML namespace identifier for this module."; } uses yang-lib-schema-leaf; uses catalog-module-metadata; list submodule { key "name revision"; description "Each entry represents one submodule within the parent module."; uses yang-lib-common-leafs; uses yang-lib-schema-leaf; } list dependencies { key "name"; description "Each entry represents one dependency."; uses yang-lib-common-leafs; uses yang-lib-schema-leaf; } list dependents { key "name"; description "Each entry represents one dependent."; uses yang-lib-common-leafs; uses yang-lib-schema-leaf; } leaf semantic-version { type yc:semver; description "The formal semantic version of a module as provided by the module itself. If the module does not provide a semantic version, this leaf will not be specified."; } leaf derived-semantic-version { type yc:semver; description "The semantic version of a module as compared to other revisions of the same module. This value is computed algorithmically by ordering all revisions of a given module and comparing them to look for backwards incompatible changes."; } container implementations { description "Container holding lists of per-module implementation details."; list implementation { key "vendor platform software-version software-flavor"; Clarke & Claise Expires October 5, 2018 [Page 21] Internet-Draft YANG Catalog April 2018 description "List of module implementations."; leaf vendor { type string; description "Organization that implements this module."; } leaf platform { type string; description "Platform on which this module is implemented."; } leaf software-version { type string; description "Name of the version of software. With respect to most network device appliances, this will be the operating system version. But for other YANG module implementation, this would be a version of appliance software. Ultimately, this should correspond to a version string that will be recognizable by the consumers of the platform."; } leaf software-flavor { type string; description "A variation of a specific version where YANG model support may be different. Depending on the vendor, this could be a license, additional software component, or a feature set."; } uses shared-implementation-leafs; uses yang-lib-implementation-leafs; } } } } container vendors { description "Container holding lists of organizations that publish YANG modules."; list vendor { key "name"; description "List of organizations publishing YANG modules."; leaf name { type string; description "Name of the maintaining organization -- the name should be supplied in the official format used by the organization. Standards Body examples: IETF, IEEE, MEF, ONF, etc. Clarke & Claise Expires October 5, 2018 [Page 22] Internet-Draft YANG Catalog April 2018 Commercial entity examples: AT&T, Facebook, Name of industry forum examples: OpenConfig, OpenDaylight, ON.Lab"; } container platforms { description "Container holding list of platforms."; list platform { key "name"; description "List of platforms under specific vendor"; leaf name { type string; description "Name of the platform"; } container software-versions { description "Container holding list of versions of software versions."; list software-version { key "name"; description "List of version of software versions under specific vendor, platform."; leaf name { type string; description "Name of the version of software. With respect to most network device appliances, this will be the operating system version. But for other YANG module implementation, this would be a version of appliance software. Ultimately, this should correspond to a version string that will be recognizable by the consumers of the platform."; } container software-flavors { description "Container holding list of software flavors."; list software-flavor { key "name"; description "List of software flavors under specific vendor, platform, software-version."; leaf name { type string; description "A variation of a specific version where YANG model support may be different. Depending on the vendor, this could be a license, additional software component, or a feature set."; } container protocols { Clarke & Claise Expires October 5, 2018 [Page 23] Internet-Draft YANG Catalog April 2018 description "List of the protocols"; list protocol { key "name"; description "YANG-based protocol that is used on the device. New identities are expected to be added to address other YANG-based protocols."; leaf name { type identityref { base yc:protocol; } description "Identity of the YANG-based protocol that is supported."; } leaf-list protocol-version { type string; description "Version of the specific protocol."; } leaf-list capabilities { type string; description "Listed name of capabilities that are supported by the specific device."; } } } container modules { description "Container holding list of modules."; list module { key "name revision organization"; description "List of references to YANG modules under specific vendor, platform, software-version, software-flavor. Using these references, the complete set of metadata can be retrieved for each module."; leaf name { type leafref { path "/catalog/modules/module/name"; } description "Reference to a name of the module that is contained in specific vendor, platform, software-version, software-flavor."; } leaf revision { type leafref { path "deref(../name)/../revision"; } Clarke & Claise Expires October 5, 2018 [Page 24] Internet-Draft YANG Catalog April 2018 description "Reference to a revision of the module that is contained in specific vendor, platform, software-version, software-flavor."; } leaf organization { type leafref { path "deref(../revision)/../organization"; } description "Reference to the authoring organization of the module for the implemented module."; } uses shared-implementation-leafs; uses yang-lib-implementation-leafs; } } } } } } } } } } } grouping catalog-module-metadata { uses shared-module-leafs; leaf compilation-status { type enumeration { enum passed { description "All compilers were able to compile this YANG module without any errors or warnings."; } enum passed-with-warnings { description "All compilers were able to compile this YANG module without any errors, but at least one of them caught a warning."; } enum failed { description "At least one of compilers found an error while compiling this YANG module."; } enum pending { description "The module was just added to the catalog and compilation testing is still Clarke & Claise Expires October 5, 2018 [Page 25] Internet-Draft YANG Catalog April 2018 in progress."; } enum unknown { description "There is not sufficient information about compilation status. This Could mean compilation crashed causing it not to complete fully."; } } description "Status of the module, whether it was possible to compile this YANG module or there are still some errors/warnings."; } leaf compilation-result { type inet:uri; description "Link to the result of the compilation explaining specifically what error or warning occurred. This is not existing if compilation status is PASSED."; } leaf prefix { type string; description "Statement of yang that is used to define the prefix associated with the module and its namespace. The prefix statement's argument is the prefix string that is used as a prefix to access a module. The prefix string MAY be used to refer to definitions contained in the module, e.g., if:ifName."; } leaf yang-version { type enumeration { enum 1.0 { description "YANG version 1.0 as defined in RFC 6020."; } enum 1.1 { description "YANG version 1.1 as defined in RFC 7950."; } } description "The optional yang-version statement specifies which version of the YANG language was used in developing the module."; } leaf description { type string; description "This statement takes as an argument a string that contains a human-readable textual description of this definition. The text is provided in a language (or languages) chosen by the Clarke & Claise Expires October 5, 2018 [Page 26] Internet-Draft YANG Catalog April 2018 module developer; for the sake of interoperability, it is RECOMMENDED to choose a language that is widely understood among the community of network administrators who will use the module."; } leaf contact { type string; description "This statement provides contact information for the module. The argument is a string that is used to specify contact information for the person or persons to whom technical queries concerning this module should be sent, such as their name, postal address, telephone number, and electronic mail address."; } leaf module-type { type enumeration { enum module { description "If YANG file contains module."; } enum submodule { description "If YANG file contains sub-module."; } } description "Whether a file contains a YANG module or sub-module."; } leaf belongs-to { when "../module-type = 'submodule'" { description "Include the module's parent when it is a submodule."; } type yang:yang-identifier; description "Name of the module that includes this submodule."; } leaf tree-type { type enumeration { enum split { description "This module uses a split config/operational state layout."; } enum nmda-compatible { description "This module is compatible with the Network Management Datastores Architecture (NMDA) and combines config and operational state nodes."; } enum transitional-extra { Clarke & Claise Expires October 5, 2018 [Page 27] Internet-Draft YANG Catalog April 2018 description "This module is derived as a '-state' module to allow for transitioning to a full NMDA-compliant tree structure."; } enum openconfig { description "This module uses the Openconfig data element layout."; } enum unclassified { description "This module does not belong to any category or can't be determined."; } enum not-applicable { description "This module is not applicable. For example, because the YANG module only contains typedefs, groupings, or is a submodule"; } } description "The type of data element tree used by the module as it relates to the Network Management Datastores Architecture."; reference "draft-dsdt-nmda-guidelines Guidelines for YANG Module Authors (NMDA)"; } leaf yang-tree { when "../module-type = 'module'"; type inet:uri; description "This leaf provides a URI that points to the ASCII tree format of the module in draft-ietf-netmod-yang-tree-diagrams format."; reference "See draft-ietf-netmod-yang-tree-diagrams."; } leaf expires { type yang:date-and-time; description "Date and time of when this module expires (if it expires). This will typically be used for modules that have not been fully ratified."; } leaf expired { type union { type boolean; type enumeration { enum not-applicable { description "This module is not and will not be expired."; } } } default "false"; description Clarke & Claise Expires October 5, 2018 [Page 28] Internet-Draft YANG Catalog April 2018 "Whether or not this module has expired. If the current date is beyond the expires date, then expired should be true."; } description "Grouping of YANG module metadata that extends the common list defined in the YANG Module Library (RFC 7895)."; } grouping organization-specific-metadata { container ietf { when "../organization = 'ietf'" { description "Include this container specific metadata of the IETF."; } leaf ietf-wg { type string; description "Working group that authored the document containing this module."; } description "Include this container for the IETF-specific organization metadata."; } description "Any organization that has some specific metadata of the yang module and want them add to the yang-catalog, should augment this grouping. This grouping is for any metadata that can`t be used for every yang module."; } grouping yang-lib-common-leafs { leaf name { type yang:yang-identifier; description "The YANG module or submodule name."; } leaf revision { type union { type yanglib:revision-identifier; type string { length "0"; } } description "The YANG module or submodule revision date. A zero-length string is used if no revision statement is present in the YANG module or submodule."; } description "The YANG module or submodule revision date. Clarke & Claise Expires October 5, 2018 [Page 29] Internet-Draft YANG Catalog April 2018 A zero-length string is used if no revision statement is present in the YANG module or submodule."; reference "RFC7895 YANG Module Library : common-leafs grouping"; } grouping yang-lib-schema-leaf { leaf schema { type inet:uri; description "Contains a URL that represents the YANG schema resource for this module or submodule. This leaf will only be present if there is a URL available for retrieval of the schema for this entry."; } description "These are a subset of leafs from the yang-library (RFC 7895) that provide some extractable fields for catalog modules. The module-list grouping cannot be used from yang-library as modules themselves cannot have conformance without a server."; reference "RFC7895 YANG Module Library : schema-leaf grouping"; } grouping yang-lib-implementation-leafs { leaf-list feature { type yang:yang-identifier; description "List of YANG feature names from this module that are supported by the server, regardless of whether they are defined in the module or any included submodule."; } list deviation { key "name revision"; description "List of YANG deviation module names and revisions used by this server to modify the conformance of the module associated with this entry. Note that the same module can be used for deviations for multiple modules, so the same entry MAY appear within multiple 'module' entries. The deviation module MUST be present in the 'module' list, with the same name and revision values. The 'conformance-type' value will be 'implement' for the deviation module."; uses yang-lib-common-leafs; } leaf conformance-type { type enumeration { enum implement { Clarke & Claise Expires October 5, 2018 [Page 30] Internet-Draft YANG Catalog April 2018 description "Indicates that the server implements one or more protocol-accessible objects defined in the YANG module identified in this entry. This includes deviation statements defined in the module. For YANG version 1.1 modules, there is at most one module entry with conformance type 'implement' for a particular module name, since YANG 1.1 requires that, at most, one revision of a module is implemented. For YANG version 1 modules, there SHOULD NOT be more than one module entry for a particular module name."; } enum import { description "Indicates that the server imports reusable definitions from the specified revision of the module but does not implement any protocol-accessible objects from this revision. Multiple module entries for the same module name MAY exist. This can occur if multiple modules import the same module but specify different revision dates in the import statements."; } } // Removing the mandatory true for now as not all vendors may have // this information if they do not implement yang-library. //mandatory true; description "Indicates the type of conformance the server is claiming for the YANG module identified by this entry."; } description "This is a set of leafs extracted from the yang-library that are specific to server implementations."; reference "RFC7895 YANG Module Library : module-list grouping"; } grouping shared-implementation-leafs { leaf os-version { type string; description "Version of the operating system using this module. This is primarily useful if the software implementing the module is an application that requires a specific operating system."; } leaf feature-set { type string; description Clarke & Claise Expires October 5, 2018 [Page 31] Internet-Draft YANG Catalog April 2018 "An optional feature of the software that is required in order to implement this module. Some form of this must be incorporated in software-version or software-flavor, but can be broken out here for additional clarity."; } leaf os-type { type string; description "Type of the operating system using this module. This is primarily useful if the software implementing the module is an application that requires a specific operating system."; } description "Grouping of non-key leafs to be used in the module and vendor sub-trees."; } grouping shared-module-leafs { leaf generated-from { type enumeration { enum mib { description "Module generated from Structure of Management Information (SMI) MIB per RFC6643."; } enum not-applicable { description "Module was not generated but it was authored manually."; } enum native { description "Module generated from platform internal, proprietary structure, or code."; } } default "not-applicable"; description "This statement defines weather the module was generated or not. Default value is set to not-applicable, which means that module was created manualy and not generated."; } leaf maturity-level { type enumeration { enum ratified { description "Maturity of a module that is fully approved (e.g., a standard)."; } enum adopted { description "Maturity of a module that is actively being developed by a organization towards ratification."; Clarke & Claise Expires October 5, 2018 [Page 32] Internet-Draft YANG Catalog April 2018 } enum initial { description "Maturity of a module that has been initially created, but has no official organization-level status."; } enum not-applicable { description "The maturity level is not used for vendor-supplied models, and thus all vendor modules will have a maturity of not-applicable"; } } description "The current maturity of the module with respect to the body that created it. This allows one to understand where the module is in its overall life cycle."; } leaf document-name { type string; description "The name of the document from which the module was extracted or taken; or that provides additional context about the module."; } leaf author-email { type yc:email-address; description "Contact email of the author who is responsible for this module."; } leaf reference { type inet:uri; description "A string that is used to specify a textual cross-reference to an external document, either another module that defines related management information, or a document that provides additional information relevant to this definition."; } leaf module-classification { type enumeration { enum network-service { description "Network Service YANG Module that describes the configuration, state data, operations, and notifications of abstract representations of services implemented on one or multiple network elements."; } enum network-element { description "Network Element YANG Module that describes the configuration, state data, operations, and notifications of specific device-centric technologies or features."; } Clarke & Claise Expires October 5, 2018 [Page 33] Internet-Draft YANG Catalog April 2018 enum unknown { description "In case that there is not sufficient information about how to classify the module."; } enum not-applicable { description "The YANG module abstraction type is neither a Network Service YANG Module nor a Network Element YANG Module."; } } mandatory true; description "The high-level classification of the given YANG module."; reference "RFC8199 YANG Module Classification"; } description "These leafs are shared among the yang-catalog and its API."; } grouping online-source-file { leaf owner { type string; mandatory true; description "Username or ID of the owner of the version control system repository."; } leaf repository { type string; mandatory true; description "The name of the repository."; } leaf path { type yc:path; mandatory true; description "Location within the repository of the module file."; } leaf branch { type string; description "Revision control system branch or tag to use to find the module. If this is not specified, the head of the repository is used."; } description "Networked version control system location of the module file."; } } Clarke & Claise Expires October 5, 2018 [Page 34] Internet-Draft YANG Catalog April 2018 5. Security Considerations The goal of the YANG Catalog module and yangcatalog.org is to document a large library of YANG modules and their implementations. Already, we have seen some SDOs hestitant to provide modules that have not reached a "ratified" maturity level because of intellectual property leakage concerns or simply organization process that mandates only fully ratified modules can be published. Care must be paid that through private automated testing and validation of such modules that their metadata does not leak before the publishing organization approves the release of such data. Similarly, from a vendor implementation standpoint, data that is exposed to the catalog before the vendor has fully vetted it could cause confusion amongst that vendor's customers or reveal product releases to the market before they have been officially announced. Ultimately, there is a balance to be struck with respect to providing a rich library of YANG module metadata, and doing so at the right time to avoid information leakage. 6. IANA Considerations No IANA action is requested. 7. References 7.1. Normative References [I-D.ietf-netmod-yang-tree-diagrams] Bjorklund, M. and L. Berger, "YANG Tree Diagrams", draft- ietf-netmod-yang-tree-diagrams-06 (work in progress), February 2018. [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [RFC7895] Bierman, A., Bjorklund, M., and K. Watsen, "YANG Module Library", RFC 7895, DOI 10.17487/RFC7895, June 2016, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . Clarke & Claise Expires October 5, 2018 [Page 35] Internet-Draft YANG Catalog April 2018 [RFC8199] Bogdanovic, D., Claise, B., and C. Moberg, "YANG Module Classification", RFC 8199, DOI 10.17487/RFC8199, July 2017, . [semver] "Semantic Versioning 2.0.0", . 7.2. Informative References [I-D.openconfig-netmod-model-catalog] Shaikh, A., Shakir, R., and K. D'Souza, "Catalog and registry for YANG models", draft-openconfig-netmod-model- catalog-02 (work in progress), March 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, . 7.3. URIs [1] https://developer.cisco.com/site/confD/index.gsp [2] https://www.yangcatalog.org/yang-search Appendix A. Acknowledgments The authors would like to thanks Miroslav Kovac for this help on this YANG module and the yangcatalog.org implementation. We would also like to thank Radek Krejci for his extensive review and suggestions for improvement. The RFC text was produced using Marshall Rose's xml2rfc tool. Clarke & Claise Expires October 5, 2018 [Page 36] Internet-Draft YANG Catalog April 2018 Appendix B. Changes From Previous Revisions RFC Editor to remove this section prior to publication. Draft -00 to -01: o Redesign of module sub-tree based on review. o Modularize some leafs and create typedefs to share with API YANG modules. o Add module conformance-type, deviation and feature leafs under the implementation branch. o Change yang-version to be an enum. o Add a leaf for module-classification based on [RFC8199]. o Normalize enums to be lowercase. o Use identities for protocols instead of an enumeration. o Make conformance-type optional as not all vendors implement [RFC7895]. o Add a leaf for tree-type based on [RFC8342]. o Add a reference to contributing to the YANG Catalog at yangcatalog.org. o Various wording and style changes to the document text. Draft -01 to -02: o Add a belongs-to leaf to track parent modules. o Add leafs to track dependents and dependencies for a given module. o Simplify the generated-from enumerated values. o Refine the type for compilation-result to be an inet:uri. o Add leafs for semantic versioning. o Reorder the organization leaf to be with other module keys. o Add text to describe generated-from and semantic versioning. Clarke & Claise Expires October 5, 2018 [Page 37] Internet-Draft YANG Catalog April 2018 Draft -02 to -03: o Change YANG ref to RFC7950 as the catalog module now needs YANG 1.1. o Add a reference to I-D.ietf-netmod-yang-tree-diagrams. o Document the new yang-tree node in the catalog. o Document the new expires and expired leafs and their relation to maturity. o Updtae NMDA reference to point to new RFC number. Authors' Addresses Joe Clarke Cisco Systems, Inc. 7200-12 Kit Creek Rd Research Triangle Park, North Carolina United States of America Phone: +1-919-392-2867 Email: jclarke@cisco.com Benoit Claise Cisco Systems, Inc. De Kleetlaan 6a b1 1831 Diegem Belgium Phone: +32 2 704 5622 Email: bclaise@cisco.com Clarke & Claise Expires October 5, 2018 [Page 38]