Github user aledsage commented on the issue:

    https://github.com/apache/brooklyn-server/pull/281
  
    @ahgittin @grkvlt @sjcorbett @neykov This all sounds scarily complicated to 
describe to users, with the actual behaviour of inheritance for a given 
parent/child entity pair being unclear to the user until they dig into that 
entity's definition.
    
    ---
    I worry about the pattern of using the `pre.install.command` on the parent 
entity. Whether that works depends on the child entity. If the child entity has 
its own value for `pre.install.command` then the parent's value would have been 
ignored (including in Brooklyn 0.9.0).
    
    I can see that your suggestion of "conflict-resolution-strategy" being 
supplied by the caller would "fix" that, but I think it would be extremely hard 
to use.
    
    ---
    Maybe I'm missing something in your proposal, but I think there is a 
fundamental problem that makes it hard to use: the inheritance mode / 
conflict-resolution mode is being defined in the config key declaration; but 
the user of the blueprint is only thinking about supplying the value in the 
`brooklyn.config` seciton.
    
    ---
    To make this feasible to use/understand in YAML blueprints, I wonder if we 
really need the feature discussed in the email thread "[PROPOSAL] separate 
shell.env per command".
    
    That proposal could be extended to support something like that below (but 
with more sensible key/values for "inherited_by_children", 
"conflict_resolution", etc)?
    
    ```
    - type: org.apache.brooklyn.entity.stock.BasicApplication
      brooklyn.config:
        pre.install:
          command: |
            sudo yum install -y my-favourite-monitoring
          inherited_by_children: true
          conflict_resolution: prefix
    ```


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