Allow config blocks with identical keys.

[wrossmann]

Unfortunately my environment is a bit of a disaster which prevents me from using your cookbook directly, but I did lift CollectdConfig::write_elements() for writing collectd configs. However, I have come across some situations where I need multiple config blocks of the same type, eg:

LoadPlugin "foo"
<Plugin "foo">
  <Ignore "bar>
    ...
  </Ignore>
  <Ignore "baz>
    ...
  </Ignore>
</Plugin>

Which doesn't work with the current version of this function, so I've modified it as follows to allow for arrays of hashes:

def write_elements(directives, indent = 0)
  tabs = ("\t" * indent)
  directives.dup.map do |key, value|
    next if value.nil?
    if value.is_a?(Array)
      value.map do |val|
        if val.is_a?(String)
          %(#{tabs}#{key} "#{val}")
        elsif val.is_a?(Hash)
          write_block(key, val, indent)
        else
          %(#{tabs}#{key} #{val})
        end
      end.join("\n")
    elsif value.kind_of?(Hash) # rubocop:disable Style/ClassCheck
      write_block(key, value, indent)
    elsif value.is_a?(String)
      %(#{tabs}#{key} "#{value}")
    else
      %(#{tabs}#{key} #{value})
    end
  end.flatten.join("\n")
end

def write_block(key, value, indent=0)
    tabs = ("\t" * indent)
    id = value.delete('id')
    if id.nil?
      id = ''
    else
      id = " \"#{id}\""
    end
    [%(#{tabs}<#{key}#{id}>),
      write_elements(value, indent.next),
      %(#{tabs}</#{key}>)
    ].join("\n")
end

So now the directive hash below will produce the desired config in the example above.

{
  'LoadPlugin' => 'foo',
  'Plugin' => {
    'id' => 'foo',
    'Ignore' => [
      {
        'id' => 'bar'
        # ...
      },
      {
        'id' => 'baz'
        # ...
      }
    ]
  }
}

[wrossmann]

Updated write_block to accommodate writing blocks with no id, eg: <Rule>