John Snow writes: [...]
This might be OK to do right away, though.
I asked Markus this not too long ago; do we want to amend the QAPI schema specification to allow commands to return with "Warning" strings, or "Deprecated" stings to allow in-band deprecation notices for cases like these?
example:
{ "return": {}, "deprecated": True, "warning": "Omitting filter-node-name parameter is deprecated, it will be required in the future" }
There's no "error" key, so this should be recognized as success by compatible clients, but they'll definitely see the extra information.
Part of my motivation is to facilitate a more aggressive deprecation of legacy features by ensuring that we are able to rigorously notify users through any means that they need to adjust their scripts.
I like this approach even if there is no consumer today. It does not hurt, and it is indeed a motivation to develop consumers that care. I personally find this much easier to swallow than any kind of crash on deprecation, which already at the BoF seemed like a really big hammer to kill a fly. CC'ing Andrea as well, because we discussed recently about how to deal with error checking in general, and if a new error checking framework is being put in place, adding deprecation to the thinking could be a good idea. -- Cheers, Christophe de Dinechin (IRC c3d)