Re: [netmod] Does defining a feature require the module be implemented?

[Andy Bierman <[e-mail]>]

On Wed, May 18, 2022 at 10:52 PM Jan Lindblad <[e-mail]> wrote:

> Andy wrote:
>
> A server can support a module without any protocol-accessible objects in 3
> ways
>    - implement the module with no features supported
>    - implement the module with features supported
>    - import the module without implementing it
>
> To Martin's point, it is not clear that a client is harmed because a
> server lists a module in
> the 'module' list instead of the 'import-only-module' list.
>
>
> Andy
>
>
> I just want to attest to the real world harm it causes when a server lists
> a module M in the modules list when it doesn't actually support it.
>
> The client then has to believe it is reasonable to issue a get-config
> request for the contents of module M. But when it does, the server then
> responds with an error, and the automation breaks down. The problem is
> cured by the server listing the non-implemented module M as an
> import-only-module.
>
>
GET operations silently skip filters that do not match.
There is no error returned. Modules are not required to contain
config data nodes, so issuing a get-config request for every module
does not seem like a good idea.

A client should be able to determine that M does not have any configuration
data nodes.
If the client does not have the correct set of server features, then
evaluation
of if-feature statements by the client may be wrong.  This causes real harm
to interoperability,

Our server implements the crypt-hash data type and implements the 3
features.
The module is (correctly) listed in the 'module' list, because it is NOT
used as an import-only module
in our server.  It is an implemented module.

Still not sure what real  problem exists here.




> /Jan
>

Andy