Re: [netmod] [Netconf] Alternative YANG library structure for 7895bis

[Robert Wilton <[e-mail]>]

I don't think that this is really a good idea.  You would end up 
returning server metadata in addition to the configuration.

I still think that the YANG library proposal is the best solution.

Thanks,
Rob


On 16/11/2017 01:21, Vladimir Vassilev wrote:
> Hello,
>
> I have a proposal based on <get-data> that provides an elegant 
> solution to consider as a 3rd option.  It is based on keeping exactly 
> the same model as in RFC 7895 and using <get-data> RPC to retrieve 
> datastore specific yang-library instance data in a similar way one 
> would use <get-data> to retrieve the datastore contents. In addition a 
> top level config=false container e.g. /datastores with list of 
> supported datastores that does not need to be part of the yang-library 
> module:
>
> module: ietf-datastores
> +--ro datastores
> |  +--ro datastore* [name]
> |     +--ro name          identityref
>
> Vladimir
>
> On 11/09/2017 05:51 PM, Robert Wilton wrote:
>>
>> Hi,
>>
>> Given some of the feedback related to the complexity of the YANG 
>> library bis structure, we have come up with two other possible 
>> structures for the YANG library data:
>>
>> (1) A simplified structure to make YANG library meet the NMDA 
>> requirements, but that is closer to the existing YANG library 
>> structure, and arguably simpler.
>> (2) An enhanced version of the structure (1) above, that is also 
>> extended to allow the structure to be reused for schema-mount via an 
>> augmentation.
>>
>> For reference, at the end of this email, I have also included the 
>> tree diagram of the existing YANG library, and the current YANG 
>> library bis draft (draft-ietf-netconf-rfc7895bis-02) version.
>>
>> Considering the two new YANG library structures:
>>
>> ------------------------
>>
>> *(1) A simplified structure to make YANG library meet the NMDA 
>> requirements, but that is closer to the existing YANG library structure.*
>>
>> The main changes are:
>> (i) Split "implemented modules" and "import-only-modules" into two 
>> separate lists, making the most important list (i.e. implemented 
>> modules) keyed by module name only and hence easier to reference.
>> (ii) Assume modules are implemented in all datastores by default 
>> (with a "not-implemented-in" leaflist of datastores that a module is 
>> not implemented in).
>> (iii) Assume that features are implemented in all datastores by 
>> default (with a "not-implemented-in" leaflist of datastores that a 
>> feature is not implemented in).
>> (iv) Deleted module-sets.
>> (v) Datastores are now just a list of supported datastores (that 
>> could potentially be extended with further per datastore properties 
>> in future).
>>
>> Manually generated tree output for proposed YANG library:
>>
>> module: ietf-yang-library
>>  +--ro yang-library
>>     +--ro modules
>>     |  +--ro module* [name]
>>     |  |  +--ro name           yang:yang-identifier
>>     |  |  +--ro revision?      revision-identifier
>>     |  |  +--ro schema?        inet:uri
>>     |  |  +--ro namespace      inet:uri
>>     |  |  +--ro submodule* [name]
>>     |  |  |  +--ro name        yang:yang-identifier
>>     |  |  |  +--ro revision?   yang:yang-identifier
>>     |  |  |  +--ro schema?     inet:uri
>>     |  |  +--ro not-implemented-in*
>>     |  |  |              -> /yang-library/datastore/name
>>     |  |  +--ro feature* [name]
>>     |  |  |  +--ro name        yang:yang-identifier
>>     |  |  |  +--ro not-implemented-in*
>>     |  |  |              -> /yang-library/datastore/name
>>     |  |  +--ro deviation*
>>     |  |                 -> ../name
>>     |  |
>>     |  +--ro import-only-module* [name revision]
>>     |     +--ro name yang:yang-identifier
>>     |     +--ro revision            union
>>     |     +--ro schema?             inet:uri
>>     |     +--ro namespace           inet:uri
>>     |     +--ro submodule* [name]
>>     |        +--ro name        yang:yang-identifier
>>     |        +--ro revision yang:revision-identifier
>>     |        +--ro schema?     inet:uri
>>     +--ro datastore* [name] // Allows future per datastore properties.
>>     |  +--ro name          identityref
>>     +--ro checksum       string
>>
>> ------------------------------
>>
>> *(2) An enhanced version of the structure (1) above, that is extended 
>> to allow the structure to be reused for schema-mount via an 
>> augmentation.*
>>
>> This is similar to the structure above, except that the "the set of 
>> modules" is contained in a list of named schema (e.g. similar to the 
>> schema mount draft), allowing this structure to be re-used for schema 
>> mount.
>>
>> Schema mount would be expected to augment yang-library to add in the 
>> additional schema mount information.  In the tree diagram, I have 
>> shown the schema-mount mount-point augmentation, but not including 
>> namespaces yet.
>>
>> Every server would be required to provide at least one schema in the 
>> schema list, and the primary schema for the device would always be 
>> given the name "primary".
>>
>> module: ietf-yang-library
>>  +--ro yang-library
>>     +--ro schema* [name]
>>     |  +--ro name           string
>>     |  +--ro checksum       string
>>     |  +--ro module* [name]
>>     |  |  +--ro name           yang:yang-identifier
>>     |  |  +--ro revision? yang:revision-identifier
>>     |  |  +--ro schema?        inet:uri
>>     |  |  +--ro namespace      inet:uri
>>     |  |  +--ro submodule* [name]
>>     |  |  |  +--ro name        yang:yang-identifier
>>     |  |  |  +--ro revision?   yang:yang-identifier
>>     |  |  |  +--ro schema?     inet:uri
>>     |  |  +--ro not-implemented-in*
>>     |  |  |              -> /yang-library/datastore/name
>>     |  |  +--ro feature* [name]
>>     |  |  |  +--ro name        yang:yang-identifier
>>     |  |  |  +--ro not-implemented-in*
>>     |  |  |              -> /yang-library/datastore/name
>>     |  |  +--ro deviation*
>>     |  |  |              -> ../name
>>     |  |  +- schema-mount:mount-point* [label]
>>     |  |     +--ro label         yang:yang-identifier
>>     |  |     +--ro config?       boolean
>>     |  |     +--ro (schema-ref)
>>     |  |        +--:(inline)
>>     |  |        |  +--ro inline?       empty
>>     |  |        +--:(use-schema)
>>     |  |           +--ro use-schema* [name]
>>     |  |              +--ro name
>>     |  |              |       -> /yang-library/schema/name
>>     |  |              +--ro parent-reference* yang:xpath1.0
>>     |  |
>>     |  +--ro import-only-module* [name revision]
>>     |     +--ro name yang:yang-identifier
>>     |     +--ro revision            union
>>     |     +--ro schema?             inet:uri
>>     |     +--ro namespace           inet:uri
>>     |     +--ro submodule* [name]
>>     |        +--ro name        yang:yang-identifier
>>     |        +--ro revision yang:revision-identifier
>>     |        +--ro schema?     inet:uri
>>     +--ro datastore* [name] // Allows future per datastore properties.
>>     |  +--ro name          identityref
>>     +--ro checksum       string
>>
>> Please can you provide comments on these structures, in particular:
>>
>> Is this version better (i.e. simpler) that the version currently in 
>> draft-ietf-netconf-rfc7895bis-02 (below)?
>>
>> Should we try and make the structure extensible for schema-mount via 
>> augmentation (i.e. version (2)), or is it better that schema-mount 
>> has its own separate subtree?
>>
>> For reference only I have included the existing YANG library and YANG 
>> library bis draft tree diagrams.
>>
>> Thanks,
>> Rob
>>
>>
>> -----------------------------
>>
>> *** FOR REFERENCE ONLY ***
>>
>> (3)  The current YANG library structure in YANG library bis 
>> (draft-ietf-netconf-rfc7895bis-02)
>>
>>     module: ietf-yang-library
>>         +--ro yang-library
>>            +--ro modules
>>            |  +--ro module* [id]
>>            |     +--ro id                  string
>>            |     +--ro name                yang:yang-identifier
>>            |     +--ro revision?           revision-identifier
>>            |     +--ro schema?             inet:uri
>>            |     +--ro namespace           inet:uri
>>            |     +--ro feature*            yang:yang-identifier
>>            |     +--ro deviation* [module]
>>            |     |  +--ro module    -> ../../id
>>            |     +--ro conformance-type    enumeration
>>            |     +--ro submodule* [name]
>>            |        +--ro name        yang:yang-identifier
>>            |        +--ro revision?   revision-identifier
>>            |        +--ro schema?     inet:uri
>>            +--ro module-sets
>>            |  +--ro module-set* [id]
>>            |     +--ro id        string
>>            |     +--ro module*   -> ../../../modules/module/id
>>            +--ro datastores
>>            |  +--ro datastore* [name]
>>            |     +--ro name          identityref
>>            |     +--ro module-set
>>            |             -> ../../../module-sets/module-set/id
>>            +--ro checksum       string
>>
>> -----------------------------
>>
>> *** FOR REFERENCE ONLY ***
>>
>> (4)  The current YANG library structure (RFC 7895)
>>
>>        +--ro modules-state
>>           +--ro module-set-id    string
>>           +--ro module* [name revision]
>>              +--ro name                yang:yang-identifier
>>              +--ro revision            union
>>              +--ro schema?             inet:uri
>>              +--ro namespace           inet:uri
>>              +--ro feature*            yang:yang-identifier
>>              +--ro deviation* [name revision]
>>              |  +--ro name        yang:yang-identifier
>>              |  +--ro revision    union
>>              +--ro conformance-type    enumeration
>>              +--ro submodule* [name revision]
>>                 +--ro name        yang:yang-identifier
>>                 +--ro revision    union
>>                 +--ro schema?     inet:uri
>>
>>
>>
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