Description of problem:
I'd like to use get_param as an input to the params mapping of str_replace, but our validation prevents it:

"ERROR: "str_replace" parameters must be a mapping"

heat_template_version: 2016-04-08

parameters:
  HostnameMap:
    type: json
    default:
      overcloud-controller-0: stevespecial-xyz-123-controller-0

  Hostname:
    type: string
    default: overcloud-controller-0

outputs:
  the_output:
    value:
      str_replace:
        template: {get_param: Hostname}
        params: {get_param: HostnameMap}

It works fine when you disable the validation, so I think we need to relax the validation such that referencing another function is considered valid, or we validate later such that the function has been resolved.


https://bugs.launchpad.net/heat/+bug/1539737