Puppet Function: create_resources_hash_from

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

Overview

create_resources_hash_from() ⇒ Any

Given:

A formatted string (to use as the resource name)
An array to loop through (because puppet cannot loop)
A hash defining the parameters for a resource
And optionally an hash of parameter names to add to the resource and an
  associated formatted string that should be configured with the current
  element of the loop array

This function will return a hash of hashes that can be used with the create_resources function.

The formatted string used as the resource name can also optionally contain ‘%index%’ which will be replaced with the array index - ie. 0 for the first entry, 1 for the second entry etc.

*Example 1:*

$allowed_hosts = ['10.0.0.0/8', '192.168.0.0/24']
$resource_name = "100 allow %s to apache on ports 80"
$my_resource_hash = {
  'proto'  => 'tcp',
  'action' => 'accept',
  'dport'  => 80
}
$dynamic_parameters = {
  'source' => '%s'
}

$created_resource_hash1 = create_resources_hash_from($resource_name, $allowed_hosts, $my_resource_hash, $dynamic_parameters)

$created_resource_hash1 would equal:

{
  '100 allow 10.0.0.0/8 to apache on ports 80' => {
    'proto' => 'tcp',
    'action' => 'accept',
    'dport' => 80,
    'source' => '10.0.0.0/8'
  },
  '100 allow 192.168.0.0/24 to apache on ports 80' => {
    'proto' => 'tcp',
    'action' => 'accept',
    'dport' => 80,
    'source' => '192.168.0.0/24'
  }
}

*Example 2:*

$software = ['jboss', 'httpd']
$resource_name = "software%index%"
$my_resource_hash = {}
$dynamic_parameters = {
  'value' => '%s'
}

$created_resource_hash2 = create_resources_hash_from($resource_name, $software, $my_resource_hash, $dynamic_parameters)

$created_resource_hash2 would equal:

{
  'software0' => {
    'value' => 'jboss',
  },
  'software1' => {
    'value' => 'httpd',
  }
}

$created_resource_hash could then be used with create_resources

create_resources(firewall, $created_resource_hash1)
create_resources('system::facts', $created_resource_hash2)

To create a bunch of resources in a way that would only otherwise be possible with a loop of some description.

Returns:

  • (Any) 


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# File 'lib/puppet/parser/functions/create_resources_hash_from.rb', line 20

newfunction(:create_resources_hash_from, :type => :rvalue, :doc => <<-EOS
Given:
  A formatted string (to use as the resource name)
  An array to loop through (because puppet cannot loop)
  A hash defining the parameters for a resource
  And optionally an hash of parameter names to add to the resource and an
    associated formatted string that should be configured with the current
    element of the loop array

This function will return a hash of hashes that can be used with the
create_resources function.

The formatted string used as the resource name can also optionally contain
'%index%' which will be replaced with the array index - ie. 0 for the first
entry, 1 for the second entry etc.

*Example 1:*
  $allowed_hosts = ['10.0.0.0/8', '192.168.0.0/24']
  $resource_name = "100 allow %s to apache on ports 80"
  $my_resource_hash = {
    'proto'  => 'tcp',
    'action' => 'accept',
    'dport'  => 80
  }
  $dynamic_parameters = {
    'source' => '%s'
  }

  $created_resource_hash1 = create_resources_hash_from($resource_name, $allowed_hosts, $my_resource_hash, $dynamic_parameters)

$created_resource_hash1 would equal:
  {
    '100 allow 10.0.0.0/8 to apache on ports 80' => {
      'proto' => 'tcp',
      'action' => 'accept',
      'dport' => 80,
      'source' => '10.0.0.0/8'
    },
    '100 allow 192.168.0.0/24 to apache on ports 80' => {
      'proto' => 'tcp',
      'action' => 'accept',
      'dport' => 80,
      'source' => '192.168.0.0/24'
    }
  }

*Example 2:*
  $software = ['jboss', 'httpd']
  $resource_name = "software%index%"
  $my_resource_hash = {}
  $dynamic_parameters = {
    'value' => '%s'
  }

  $created_resource_hash2 = create_resources_hash_from($resource_name, $software, $my_resource_hash, $dynamic_parameters)

$created_resource_hash2 would equal:
  {
    'software0' => {
      'value' => 'jboss',
    },
    'software1' => {
      'value' => 'httpd',
    }
  }

$created_resource_hash could then be used with create_resources

  create_resources(firewall, $created_resource_hash1)
  create_resources('system::facts', $created_resource_hash2)

To create a bunch of resources in a way that would only otherwise be possible
with a loop of some description.
  EOS
) do |arguments|

  raise Puppet::ParseError, "create_resources_hash_from(): Wrong number of arguments " +
    "given (#{arguments.size} for 3 or 4)" if arguments.size < 3 or arguments.size > 4

  formatted_string = arguments[0]

  unless formatted_string.is_a?(String)
    raise(Puppet::ParseError, 'create_resources_hash_from(): first argument must be a string')
  end

  loop_array = arguments[1]

  unless loop_array.is_a?(Array)
    raise(Puppet::ParseError, 'create_resources_hash_from(): second argument must be an array')
  end

  resource_hash = arguments[2]
  unless resource_hash.is_a?(Hash)
    raise(Puppet::ParseError, 'create_resources_hash_from(): third argument must be a hash')
  end

  if arguments.size == 4
    dynamic_parameters = arguments[3]
    unless dynamic_parameters.is_a?(Hash)
      raise(Puppet::ParseError, 'create_resources_hash_from(): fourth argument must be a hash')
    end
  end

  result = {}

  loop_array.each_with_index do |i, index|
    my_resource_hash = resource_hash.clone
    if dynamic_parameters
      dynamic_parameters.each do |param, value|
        if my_resource_hash.member?(param)
          raise(Puppet::ParseError, "create_resources_hash_from(): dynamic_parameter '#{param}' already exists in resource hash")
        end
        my_resource_hash[param] = value..gsub('%index%', "#{index}")
        my_resource_hash[param] = sprintf(value,[i])
      end
    end
    key = formatted_string.gsub('%index%', "#{index}")
    result[sprintf(key,[i])] = my_resource_hash
  end

  result
end