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From aledsage <...@git.apache.org>
Subject [GitHub] brooklyn-docs issue #182: Enforce the use of `brooklyn.config` in yaml examp...
Date Mon, 15 May 2017 09:42:20 GMT
Github user aledsage commented on the issue:

    https://github.com/apache/brooklyn-docs/pull/182
  
    @tbouron I agree in principle with this change, however I have a big reservation about
doing this now.
    
    First, my agreements:
    * We should be consistent in our examples and in what we support. We should always use
`brooklyn.config` (or if not, then we should have a separate proposal to never use it).
    * We should have one authoritative name for the each config key, and always use that in
our examples. We should deprecate the other aliases.
    
    Now for my disagreement... Once we have support for deprecating config key names, we should
carefully decide which name we want to be the authoritative name (is the the current "real"
name, or is the alias actually a better name; or is there a new name we should change it to
that is more consistent with the rest of Brooklyn!)
    
    Therefore I worry that this PR will change our examples, and then we'll change some of
those back again when we figure out what the best names are. As an example, the `AutoScalerPolicy`'s
config key should be `metric` rather than `autoscaler.metric` - i.e. the name used in the
alias should be switched to be the authoritative name. Having the prefix "autoscaler" is just
needless repetition.
    
    What makes the long-term choice of naming a bit tricky is our support for runtime-management
config inheritance, i.e. inheriting config keys from a parent entity (*). Where a user does
that, we want to reduce the risk of name collisions. But frankly I think we want to discourage
it!
    
    (*) Our current behaviour is horrible - a config value that uses the alias is not picked
up the child entities, but a config key that uses the "real name" is picked up. However, users
find it extremely hard to tell the difference between "real name" and "alias" when they're
looking at examples, so invariably find this behaviour baffling.


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