Puppet Function: getparam

Defined in:
vendor_modules/stdlib/lib/puppet/parser/functions/getparam.rb
Function type:
Ruby 3.x API

Summary

Returns the value of a resource's parameter.

Overview

getparam() ⇒ Any

Takes a resource reference and name of the parameter and returns value of resource's parameter. Note that user defined resource types are evaluated lazily.

Would notice: 'the value we are getting in this example'

> *Note* that since Puppet 4.0.0 it is possible to get a parameter value by using its data type and the [ ] operator. The example below is equivalent to a call to getparam():

```Example_resource['example_resource_instance']['param']``

Examples:

Example Usage:


# define a resource type with a parameter
define example_resource($param) {
}

# declare an instance of that type
example_resource { "example_resource_instance":
    param => "'the value we are getting in this example''"
}

# Because of order of evaluation, a second definition is needed
# that will be evaluated after the first resource has been declared
#
define example_get_param {
  # This will notice the value of the parameter
  notice(getparam(Example_resource["example_resource_instance"], "param"))
}

# Declare an instance of the second resource type - this will call notice
example_get_param { 'show_notify': }

Returns:

  • (Any) —

    value of a resource's parameter.



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# File 'vendor_modules/stdlib/lib/puppet/parser/functions/getparam.rb', line 6

Puppet::Parser::Functions.newfunction(:getparam, type: :rvalue, doc: <<-'DOC'
    @summary
      Returns the value of a resource's parameter.

    @return
      value of a resource's parameter.

    Takes a resource reference and name of the parameter and
    returns value of resource's parameter. Note that user defined
    resource types are evaluated lazily.

    @example Example Usage:

      # define a resource type with a parameter
      define example_resource($param) {
      }

      # declare an instance of that type
      example_resource { "example_resource_instance":
          param => "'the value we are getting in this example''"
      }

      # Because of order of evaluation, a second definition is needed
      # that will be evaluated after the first resource has been declared
      #
      define example_get_param {
        # This will notice the value of the parameter
        notice(getparam(Example_resource["example_resource_instance"], "param"))
      }

      # Declare an instance of the second resource type - this will call notice
      example_get_param { 'show_notify': }

    Would notice: 'the value we are getting in this example'

    > **Note** that since Puppet 4.0.0 it is possible to get a parameter value by using its data type
    and the [ ] operator. The example below is equivalent to a call to getparam():
      ```Example_resource['example_resource_instance']['param']``

  DOC
) do |vals|
  reference, param = vals
  raise(ArgumentError, 'Must specify a reference') unless reference
  raise(ArgumentError, 'Must specify name of a parameter') unless param&.instance_of?(String)

  return '' if param.empty?

  resource = findresource(reference.to_s)
  if resource
    return resource[param] unless resource[param].nil?
  end

  return ''
end