Re: [PATCH] doc: add deprecation for restrictions in telemetry naming

[Bruce Richardson <bruce.richardson@intel.com>]

On Fri, Jul 08, 2022 at 12:06:31AM +0200, Morten Brørup wrote:
> > From: Bruce Richardson [mailto:bruce.richardson@intel.com]
> > Sent: Thursday, 7 July 2022 15.40
> > 
> > Following discussion on-list [1], we will look to limited the allowed
> > characters in names for items in telemetry. This will simplify the
> > escaping needed for json output, or any future output formats. The
> > lists
> > will initially be minimal, since expansion to allow more characters can
> > be done without affecting compatibility, while reducing the set cannot.
> > 
> > Cc: mb@smartsharesystems.com
> > Cc: stephen@networkplumber.org
> > Cc: ciara.power@intel.com
> > 
> > Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> > 
> > [1] http://inbox.dpdk.org/dev/20220623164245.561371-1-
> > bruce.richardson@intel.com/#r
> > ---
> >  doc/guides/rel_notes/deprecation.rst | 6 ++++++
> >  1 file changed, 6 insertions(+)
> > 
> > diff --git a/doc/guides/rel_notes/deprecation.rst
> > b/doc/guides/rel_notes/deprecation.rst
> > index 4e5b23c53d..9366690ec5 100644
> > --- a/doc/guides/rel_notes/deprecation.rst
> > +++ b/doc/guides/rel_notes/deprecation.rst
> > @@ -119,6 +119,12 @@ Deprecation Notices
> >  * metrics: The function ``rte_metrics_init`` will have a non-void
> > return
> >    in order to notify errors instead of calling ``rte_exit``.
> > 
> > +* telemetry: The allowed characters in names for dictionary values
> > will be limited to
> > +  alphanumeric characters and a small subset of additional printable
> > characters.
> > +  This will ensure that all dictionary parameter names can be output
> > without escaping
> > +  in json - or in any future output format used. Names for the
> 
> json -> JSON
> 
Capital idea! (pun very much intended :-) )

> > telemetry commands will
> > +  be similarly limited.
> 
> Perhaps also add a comment about parameters to telemetry commands, for completeness.
> 

I was not intending to impose restrictions on the parameters themselves
since currently they are not output as part of any json. However, now you
have got me thinking that perhaps we should look to scan parameters for
invalid characters before we hand them over to the individual functions.
That would allow the possibility of including parameters in any replies in
a future format.

Was this what you had in mind, or any other thoughts?

/Bruce