Dynamic method calls in CFEngine

  R: in bundle agent handler1: I got value1


  R: in bundle agent handler1: I got value2


   !! Method invoked repairs


   !! Method invoked repairs


  R: in bundle agent handler2: I got value1


  R: in bundle agent handler2: I got value2


   !! Method invoked repairs


   !! Method invoked repairs


  

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Breakdown

bundle agent main

Here we define two lists, a list of bundle names and a list of values. Because of implicit list iteration we then call “handler_iterator” 2 times. Once for each value of the mybundles list. Each activation also passes in the myvalues list.

Bundle agent handler_iterator

handler_iterator is where the neat part happens. You can see that we call the bundle $(handler) (outside of quotes) with the parameter @(handler_iterator.values). This is what I found so interesting. I Have called bundles dynamically in the past, but I have always put the variable inside of quotes. That worked fine but it prevented me from using parameters when calling because the parameters were seen as part of the bundle name.  Here is an example of the handler_iterator bundle trying to use a parametrized value inside of quotes.

  bundle agent handler_iterator(handler, values)


  # This expects a single value


  {


  methods:


    "$(handler) $(values)" usebundle => "$(handler)($(values))";


  



  }

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