[ClusterLabs Developers] Validation of resource meta-attributes

[Ondrej Mular]

Hi all,

during summit in Nuremberg, there was a discussion about improving
usability. One of mentioned areas was validation of resource meta-
attributes.

There was an idea to have meta-attributes as element attributes of
resource elements (primitive/group/clone/master/bundle) in CIB. With
this approach meta-attributes will be validated directly against CIB
scheme. But this idea was rejected right away because it doesn't work
with meta-attributes used with rules.

Maybe better way to solve this would be to do it in similar fashion as
cluster properties. Pacemaker provides definition of cluster properties
in same XML metadata format as resource-agents have.

If we can obtain definition of meta-attributes metadata from pacemaker
in similar format, then each CLI can validate meta-attributes against
this definition and in GUI setting of them can be more user friendly.
Also, we can take advantage of this format and put there some
understandable description (maybe also name/label of meta-attribute)
and much more. Actually, marx is working on some improvements of ocf
XML metadata format so we can have more useful information for UIs.

Currently, pcs doesn't do any validation of resource meta-attributes.
We were thinking about some validation, but we will have to hardcode it
into pcs and update it every time some changes happen in pacemaker.
With metadata approach, change in definition would be sufficient.

What is your opinion on this?

Ondrej