List of built-in functions

NOTE: This page was generated from the Puppet source code on 2018-08-28 06:48:02 -0700

This page is a list of Puppet’s built-in functions, with descriptions of what they do and how to use them.

Functions are plugins you can call during catalog compilation. A call to any function is an expression that resolves to a value. For more information on how to call functions, see the language reference page about function calls.

Many of these function descriptions include auto-detected signatures, which are short reminders of the function’s allowed arguments. These signatures aren’t identical to the syntax you use to call the function; instead, they resemble a parameter list from a Puppet class, defined resource type, function, or lambda. The syntax of a signature is:

<FUNCTION NAME>(<DATA TYPE> <ARGUMENT NAME>, ...)

The <DATA TYPE> is a Puppet data type value, like String or Optional[Array[String]]. The <ARGUMENT NAME> is a descriptive name chosen by the function’s author to indicate what the argument is used for.

• Any arguments with an Optional data type can be omitted from the function call.
• Arguments that start with an asterisk (like *$values) can be repeated any number of times.
• Arguments that start with an ampersand (like &$block) aren’t normal arguments; they represent a code block, provided with Puppet’s lambda syntax.

alert

• alert(Any *$values)
  • *values — The values to log.
  • Return type(s): Undef.

Logs a message on the server at level alert.

all

• all(Hash[Any, Any] $hash, Callable[2,2] &$block)
  • Return type(s): Any.
• all(Hash[Any, Any] $hash, Callable[1,1] &$block)
  • Return type(s): Any.
• all(Iterable $enumerable, Callable[2,2] &$block)
  • Return type(s): Any.
• all(Iterable $enumerable, Callable[1,1] &$block)
  • Return type(s): Any.

Runs a lambda repeatedly using each value in a data structure until the lambda returns a non “truthy” value which makes the function return false, or if the end of the iteration is reached, true is returned.

This function takes two mandatory arguments, in this order:

1. An array, hash, or other iterable object that the function will iterate over.
2. A lambda, which the function calls for each element in the first argument. It can request one or two parameters.

$data.all |$parameter| { <PUPPET CODE BLOCK> }

or

all($data) |$parameter| { <PUPPET CODE BLOCK> }

# For the array $data, run a lambda that checks that all values are multiples of 10
$data = [10, 20, 30]
notice $data.all |$item| { $item % 10 == 0 }

Would notice true.

When the first argument is a Hash, Puppet passes each key and value pair to the lambda as an array in the form [key, value].

# For the hash $data, run a lambda using each item as a key-value array
$data = { 'a_0'=> 10, 'b_1' => 20 }
notice $data.all |$item| { $item[1] % 10 == 0  }

Would notice true if all values in the hash are multiples of 10.

When the lambda accepts two arguments, the first argument gets the index in an array or the key from a hash, and the second argument the value.

# Check that all values are a multiple of 10 and keys start with 'abc'
$data = {abc_123 => 10, abc_42 => 20, abc_blue => 30}
notice $data.all |$key, $value| { $value % 10 == 0  and $key =~ /^abc/ }

Would notice true.

For an general examples that demonstrates iteration, see the Puppet iteration documentation.

annotate

• annotate(Type[Annotation] $type, Any $value, Optional[Callable[0, 0]] &$block)
  • Return type(s): Any.
• annotate(Type[Annotation] $type, Any $value, Variant[Enum[clear],Hash[Pcore::MemberName,Any]] $annotation_hash)
  • Return type(s): Any.
• annotate(Type[Pcore] $type, Any $value, Hash[Type[Annotation], Hash[Pcore::MemberName,Any]] $annotations)
  • Return type(s): Any.

Handles annotations on objects. The function can be used in four different ways.

With two arguments, an Annotation type and an object, the function returns the annotation for the object of the given type, or undef if no such annotation exists.

$annotation = Mod::NickNameAdapter.annotate(o)

$annotation = annotate(Mod::NickNameAdapter.annotate, o)

With three arguments, an Annotation type, an object, and a block, the function returns the annotation for the object of the given type, or annotates it with a new annotation initialized from the hash returned by the given block when no such annotation exists. The block will not be called when an annotation of the given type is already present.

$annotation = Mod::NickNameAdapter.annotate(o) || { { 'nick_name' => 'Buddy' } }

$annotation = annotate(Mod::NickNameAdapter.annotate, o) || { { 'nick_name' => 'Buddy' } }

With three arguments, an Annotation type, an object, and an Hash, the function will annotate the given object with a new annotation of the given type that is initialized from the given hash. An existing annotation of the given type is discarded.

$annotation = Mod::NickNameAdapter.annotate(o, { 'nick_name' => 'Buddy' })

$annotation = annotate(Mod::NickNameAdapter.annotate, o, { 'nick_name' => 'Buddy' })

With three arguments, an Annotation type, an object, and an the string clear, the function will clear the annotation of the given type in the given object. The old annotation is returned if it existed.

$annotation = Mod::NickNameAdapter.annotate(o, clear)

$annotation = annotate(Mod::NickNameAdapter.annotate, o, clear)

With three arguments, the type Pcore, an object, and a Hash of hashes keyed by Annotation types, the function will annotate the given object with all types used as keys in the given hash. Each annotation is initialized with the nested hash for the respective type. The annotated object is returned.

  $person = Pcore.annotate(Mod::Person({'name' => 'William'}), {
    Mod::NickNameAdapter >= { 'nick_name' => 'Bill' },
    Mod::HobbiesAdapter => { 'hobbies' => ['Ham Radio', 'Philatelist'] }
  })

any

• any(Hash[Any, Any] $hash, Callable[2,2] &$block)
  • Return type(s): Any.
• any(Hash[Any, Any] $hash, Callable[1,1] &$block)
  • Return type(s): Any.
• any(Iterable $enumerable, Callable[2,2] &$block)
  • Return type(s): Any.
• any(Iterable $enumerable, Callable[1,1] &$block)
  • Return type(s): Any.

Runs a lambda repeatedly using each value in a data structure until the lambda returns a “truthy” value which makes the function return true, or if the end of the iteration is reached, false is returned.

This function takes two mandatory arguments, in this order:

1. An array, hash, or other iterable object that the function will iterate over.
2. A lambda, which the function calls for each element in the first argument. It can request one or two parameters.

$data.any |$parameter| { <PUPPET CODE BLOCK> }

or

any($data) |$parameter| { <PUPPET CODE BLOCK> }

# For the array $data, run a lambda that checks if an unknown hash contains those keys
$data = ["routers", "servers", "workstations"]
$looked_up = lookup('somekey', Hash)
notice $data.any |$item| { $looked_up[$item] }

Would notice true if the looked up hash had a value that is neither false nor undef for at least one of the keys. That is, it is equivalent to the expression $looked_up[routers] || $looked_up[servers] || $looked_up[workstations].

When the first argument is a Hash, Puppet passes each key and value pair to the lambda as an array in the form [key, value].

# For the hash $data, run a lambda using each item as a key-value array.
$data = {"rtr" => "Router", "svr" => "Server", "wks" => "Workstation"}
$looked_up = lookup('somekey', Hash)
notice $data.any |$item| { $looked_up[$item[0]] }

Would notice true if the looked up hash had a value for one of the wanted key that is neither false nor undef.

When the lambda accepts two arguments, the first argument gets the index in an array or the key from a hash, and the second argument the value.

# Check if there is an even numbered index that has a non String value
$data = [key1, 1, 2, 2]
notice $data.any |$index, $value| { $index % 2 == 0 and $value !~ String }

Would notice true as the index 2 is even and not a String

For an general examples that demonstrates iteration, see the Puppet iteration documentation.

assert_type

• assert_type(Type $type, Any $value, Optional[Callable[Type, Type]] &$block)
  • Return type(s): Any.
• assert_type(String $type_string, Any $value, Optional[Callable[Type, Type]] &$block)
  • Return type(s): Any.

Returns the given value if it is of the given data type, or otherwise either raises an error or executes an optional two-parameter lambda.

The function takes two mandatory arguments, in this order:

1. The expected data type.
2. A value to compare against the expected data type.

$raw_username = 'Amy Berry'

# Assert that $raw_username is a non-empty string and assign it to $valid_username.
$valid_username = assert_type(String[1], $raw_username)

# $valid_username contains "Amy Berry".
# If $raw_username was an empty string or a different data type, the Puppet run would
# fail with an "Expected type does not match actual" error.

You can use an optional lambda to provide enhanced feedback. The lambda takes two mandatory parameters, in this order:

1. The expected data type as described in the function’s first argument.
2. The actual data type of the value.

$raw_username = 'Amy Berry'

# Assert that $raw_username is a non-empty string and assign it to $valid_username.
# If it isn't, output a warning describing the problem and use a default value.
$valid_username = assert_type(String[1], $raw_username) |$expected, $actual| {
  warning( "The username should be \'${expected}\', not \'${actual}\'. Using 'anonymous'." )
  'anonymous'
}

# $valid_username contains "Amy Berry".
# If $raw_username was an empty string, the Puppet run would set $valid_username to
# "anonymous" and output a warning: "The username should be 'String[1, default]', not
# 'String[0, 0]'. Using 'anonymous'."

For more information about data types, see the documentation.

binary_file

• binary_file(String $path)
  • Return type(s): Any.

Loads a binary file from a module or file system and returns its contents as a Binary. The argument to this function should be a <MODULE NAME>/<FILE> reference, which will load <FILE> from a module’s files directory. (For example, the reference mysql/mysqltuner.pl will load the file <MODULES DIRECTORY>/mysql/files/mysqltuner.pl.)

This function also accepts an absolute file path that allows reading binary file content from anywhere on disk.

An error is raised if the given file does not exists.

To search for the existence of files, use the find_file() function.

• since 4.8.0

break

• break()
  • Return type(s): Any.

Breaks an innermost iteration as if it encountered an end of input. This function does not return to the caller.

The signal produced to stop the iteration bubbles up through the call stack until either terminating the innermost iteration or raising an error if the end of the call stack is reached.

The break() function does not accept an argument.

$data = [1,2,3]
notice $data.map |$x| { if $x == 3 { break() } $x*10 }

Would notice the value [10, 20]

function break_if_even($x) {
  if $x % 2 == 0 { break() }
}
$data = [1,2,3]
notice $data.map |$x| { break_if_even($x); $x*10 }

Would notice the value [10]

• Also see functions next and return

call

• call(String $function_name, Any *$arguments, Optional[Callable] &$block)
  • Return type(s): Any.

Calls an arbitrary Puppet function by name.

This function takes one mandatory argument and one or more optional arguments:

1. A string corresponding to a function name.
2. Any number of arguments to be passed to the called function.
3. An optional lambda, if the function being called supports it.

$a = 'notice'
call($a, 'message')

$a = 'each'
$b = [1,2,3]
call($a, $b) |$item| {
 notify { $item: }
}

The call function can be used to call either Ruby functions or Puppet language functions.

contain

• contain(Any *$names)
  • Return type(s): Any.

Makes one or more classes be contained inside the current class. If any of these classes are undeclared, they will be declared as if there were declared with the include function. Accepts a class name, an array of class names, or a comma-separated list of class names.

A contained class will not be applied before the containing class is begun, and will be finished before the containing class is finished.

You must use the class’s full name; relative names are not allowed. In addition to names in string form, you may also directly use Class and Resource Type-values that are produced by evaluating resource and relationship expressions.

The function returns an array of references to the classes that were contained thus allowing the function call to contain to directly continue.

• Since 4.0.0 support for Class and Resource Type-values, absolute names
• Since 4.7.0 a value of type Array[Type[Class[n]]] is returned with all the contained classes

convert_to

• convert_to(Any $value, Type $type, Optional[Callable[1,1]] &$block)
  • Return type(s): Any.

The convert_to(value, type) is a convenience function that does the same as new(type, value). The difference in the argument ordering allows it to be used in chained style for improved readability “left to right”.

When the function is given a lambda, it is called with the converted value, and the function returns what the lambda returns, otherwise the converted value.

  # The harder to read variant:
  # Using new operator - that is "calling the type" with operator ()
  Hash(Array("abc").map |$i,$v| { [$i, $v] })

  # The easier to read variant:
  # using 'convert_to'
  "abc".convert_to(Array).map |$i,$v| { [$i, $v] }.convert_to(Hash)

create_resources

• create_resources()
  • Return type(s): Any.

Converts a hash into a set of resources and adds them to the catalog.

This function takes two mandatory arguments: a resource type, and a hash describing a set of resources. The hash should be in the form {title => {parameters} }:

# A hash of user resources:
$myusers = {
  'nick' => { uid    => '1330',
              gid    => allstaff,
              groups => ['developers', 'operations', 'release'], },
  'dan'  => { uid    => '1308',
              gid    => allstaff,
              groups => ['developers', 'prosvc', 'release'], },
}

create_resources(user, $myusers)

A third, optional parameter may be given, also as a hash:

$defaults = {
  'ensure'   => present,
  'provider' => 'ldap',
}

create_resources(user, $myusers, $defaults)

The values given on the third argument are added to the parameters of each resource present in the set given on the second argument. If a parameter is present on both the second and third arguments, the one on the second argument takes precedence.

This function can be used to create defined resources and classes, as well as native resources.

Virtual and Exported resources may be created by prefixing the type name with @ or @@ respectively. For example, the $myusers hash may be exported in the following manner:

create_resources("@@user", $myusers)

The $myusers may be declared as virtual resources using:

create_resources("@user", $myusers)

Note that create_resources will filter out parameter values that are undef so that normal data binding and puppet default value expressions are considered (in that order) for the final value of a parameter (just as when setting a parameter to undef in a puppet language resource declaration).

crit

• crit(Any *$values)
  • *values — The values to log.
  • Return type(s): Undef.

Logs a message on the server at level crit.

debug

• debug(Any *$values)
  • *values — The values to log.
  • Return type(s): Undef.

Logs a message on the server at level debug.

defined

• defined(Variant[String, Type[CatalogEntry], Type[Type[CatalogEntry]]] *$vals)
  • Return type(s): Any.

Determines whether a given class or resource type is defined and returns a Boolean value. You can also use defined to determine whether a specific resource is defined, or whether a variable has a value (including undef, as opposed to the variable never being declared or assigned).

This function takes at least one string argument, which can be a class name, type name, resource reference, or variable reference of the form '$name'. (Note that the $ sign is included in the string which must be in single quotes to prevent the $ character to be interpreted as interpolation.

The defined function checks both native and defined types, including types provided by modules. Types and classes are matched by their names. The function matches resource declarations by using resource references.

# Matching resource types
defined("file")
defined("customtype")

# Matching defines and classes
defined("foo")
defined("foo::bar")

# Matching variables (note the single quotes)
defined('$name')

# Matching declared resources
defined(File['/tmp/file'])

Puppet depends on the configuration’s evaluation order when checking whether a resource is declared.

# Assign values to $is_defined_before and $is_defined_after using identical `defined`
# functions.

$is_defined_before = defined(File['/tmp/file'])

file { "/tmp/file":
  ensure => present,
}

$is_defined_after = defined(File['/tmp/file'])

# $is_defined_before returns false, but $is_defined_after returns true.

This order requirement only refers to evaluation order. The order of resources in the configuration graph (e.g. with before or require) does not affect the defined function’s behavior.

Warning: Avoid relying on the result of the defined function in modules, as you might not be able to guarantee the evaluation order well enough to produce consistent results. This can cause other code that relies on the function’s result to behave inconsistently or fail.

If you pass more than one argument to defined, the function returns true if any of the arguments are defined. You can also match resources by type, allowing you to match conditions of different levels of specificity, such as whether a specific resource is of a specific data type.

file { "/tmp/file1":
  ensure => file,
}

$tmp_file = file { "/tmp/file2":
  ensure => file,
}

# Each of these statements return `true` ...
defined(File['/tmp/file1'])
defined(File['/tmp/file1'],File['/tmp/file2'])
defined(File['/tmp/file1'],File['/tmp/file2'],File['/tmp/file3'])
# ... but this returns `false`.
defined(File['/tmp/file3'])

# Each of these statements returns `true` ...
defined(Type[Resource['file','/tmp/file2']])
defined(Resource['file','/tmp/file2'])
defined(File['/tmp/file2'])
defined('$tmp_file')
# ... but each of these returns `false`.
defined(Type[Resource['exec','/tmp/file2']])
defined(Resource['exec','/tmp/file2'])
defined(File['/tmp/file3'])
defined('$tmp_file2')

dig

• dig(Optional[Collection] $data, Any *$arg)
  • Return type(s): Any.

Returns a value for a sequence of given keys/indexes into a structure, such as an array or hash.

This function is used to “dig into” a complex data structure by using a sequence of keys / indexes to access a value from which the next key/index is accessed recursively.

The first encountered undef value or key stops the “dig” and undef is returned.

An error is raised if an attempt is made to “dig” into something other than an undef (which immediately returns undef), an Array or a Hash.

$data = {a => { b => [{x => 10, y => 20}, {x => 100, y => 200}]}}
notice $data.dig('a', 'b', 1, 'x')

Would notice the value 100.

This is roughly equivalent to $data['a']['b'][1]['x']. However, a standard index will return an error and cause catalog compilation failure if any parent of the final key ('x') is undef. The dig function will return undef, rather than failing catalog compilation. This allows you to check if data exists in a structure without mandating that it always exists.

digest

• digest()
  • Return type(s): Any.

Returns a hash value from a provided string using the digest_algorithm setting from the Puppet config file.

each

• each(Hash[Any, Any] $hash, Callable[2,2] &$block)
  • Return type(s): Any.
• each(Hash[Any, Any] $hash, Callable[1,1] &$block)
  • Return type(s): Any.
• each(Iterable $enumerable, Callable[2,2] &$block)
  • Return type(s): Any.
• each(Iterable $enumerable, Callable[1,1] &$block)
  • Return type(s): Any.

Runs a lambda repeatedly using each value in a data structure, then returns the values unchanged.

This function takes two mandatory arguments, in this order:

1. An array, hash, or other iterable object that the function will iterate over.
2. A lambda, which the function calls for each element in the first argument. It can request one or two parameters.

$data.each |$parameter| { <PUPPET CODE BLOCK> }

or

each($data) |$parameter| { <PUPPET CODE BLOCK> }

When the first argument ($data in the above example) is an array, Puppet passes each value in turn to the lambda, then returns the original values.

# For the array $data, run a lambda that creates a resource for each item.
$data = ["routers", "servers", "workstations"]
$data.each |$item| {
 notify { $item:
   message => $item
 }
}
# Puppet creates one resource for each of the three items in $data. Each resource is
# named after the item's value and uses the item's value in a parameter.

When the first argument is a hash, Puppet passes each key and value pair to the lambda as an array in the form [key, value] and returns the original hash.

# For the hash $data, run a lambda using each item as a key-value array that creates a
# resource for each item.
$data = {"rtr" => "Router", "svr" => "Server", "wks" => "Workstation"}
$data.each |$items| {
 notify { $items[0]:
   message => $items[1]
 }
}
# Puppet creates one resource for each of the three items in $data, each named after the
# item's key and containing a parameter using the item's value.

When the first argument is an array and the lambda has two parameters, Puppet passes the array’s indexes (enumerated from 0) in the first parameter and its values in the second parameter.

# For the array $data, run a lambda using each item's index and value that creates a
# resource for each item.
$data = ["routers", "servers", "workstations"]
$data.each |$index, $value| {
 notify { $value:
   message => $index
 }
}
# Puppet creates one resource for each of the three items in $data, each named after the
# item's value and containing a parameter using the item's index.

When the first argument is a hash, Puppet passes its keys to the first parameter and its values to the second parameter.

# For the hash $data, run a lambda using each item's key and value to create a resource
# for each item.
$data = {"rtr" => "Router", "svr" => "Server", "wks" => "Workstation"}
$data.each |$key, $value| {
 notify { $key:
   message => $value
 }
}
# Puppet creates one resource for each of the three items in $data, each named after the
# item's key and containing a parameter using the item's value.

For an example that demonstrates how to create multiple file resources using each, see the Puppet iteration documentation.

emerg

• emerg(Any *$values)
  • *values — The values to log.
  • Return type(s): Undef.

Logs a message on the server at level emerg.

empty

• empty(Collection $coll)
  • Return type(s): Any.
• empty(String $str)
  • Return type(s): Any.
• empty(Numeric $num)
  • Return type(s): Any.
• empty(Binary $bin)
  • Return type(s): Any.
• empty(Undef $x)
  • Return type(s): Any.

Returns true if the given argument is an empty collection of values.

This function can answer if one of the following is empty:

• Array, Hash - having zero entries
• String, Binary - having zero length

For backwards compatibility with the stdlib function with the same name the following data types are also accepted by the function instead of raising an error. Using these is deprecated and will raise a warning:

• Numeric - false is returned for all Numeric values.
• Undef - true is returned for all Undef values.

notice([].empty)
notice(empty([]))
# would both notice 'true'

epp

• epp(String $path, Optional[Hash[Pattern[/^\w+$/], Any]] $parameters)
  • Return type(s): Any.

Evaluates an Embedded Puppet (EPP) template file and returns the rendered text result as a String.

epp('<MODULE NAME>/<TEMPLATE FILE>', <PARAMETER HASH>)

The first argument to this function should be a <MODULE NAME>/<TEMPLATE FILE> reference, which loads <TEMPLATE FILE> from <MODULE NAME>’s templates directory. In most cases, the last argument is optional; if used, it should be a hash that contains parameters to pass to the template.

• See the template documentation for general template usage information.
• See the EPP syntax documentation for examples of EPP.

For example, to call the apache module’s templates/vhost/_docroot.epp template and pass the docroot and virtual_docroot parameters, call the epp function like this:

epp('apache/vhost/_docroot.epp', { 'docroot' => '/var/www/html', 'virtual_docroot' => '/var/www/example' })

This function can also accept an absolute path, which can load a template file from anywhere on disk.

Puppet produces a syntax error if you pass more parameters than are declared in the template’s parameter tag. When passing parameters to a template that contains a parameter tag, use the same names as the tag’s declared parameters.

Parameters are required only if they are declared in the called template’s parameter tag without default values. Puppet produces an error if the epp function fails to pass any required parameter.

err

• err(Any *$values)
  • *values — The values to log.
  • Return type(s): Undef.

Logs a message on the server at level err.

eyaml_lookup_key

• eyaml_lookup_key(String[1] $key, Hash[String[1],Any] $options, Puppet::LookupContext $context)
  • Return type(s): Any.

The eyaml_lookup_key is a hiera 5 lookup_key data provider function. See the configuration guide documentation for how to use this function.

fail

• fail()
  • Return type(s): Any.

Fail with a parse error.

file

• file()
  • Return type(s): Any.

Loads a file from a module and returns its contents as a string.

The argument to this function should be a <MODULE NAME>/<FILE> reference, which will load <FILE> from a module’s files directory. (For example, the reference mysql/mysqltuner.pl will load the file <MODULES DIRECTORY>/mysql/files/mysqltuner.pl.)

This function can also accept:

• An absolute path, which can load a file from anywhere on disk.
• Multiple arguments, which will return the contents of the first file found, skipping any files that don’t exist.

filter

• filter(Hash[Any, Any] $hash, Callable[2,2] &$block)
  • Return type(s): Any.
• filter(Hash[Any, Any] $hash, Callable[1,1] &$block)
  • Return type(s): Any.
• filter(Iterable $enumerable, Callable[2,2] &$block)
  • Return type(s): Any.
• filter(Iterable $enumerable, Callable[1,1] &$block)
  • Return type(s): Any.

Applies a lambda to every value in a data structure and returns an array or hash containing any elements for which the lambda evaluates to true.

This function takes two mandatory arguments, in this order:

1. An array, hash, or other iterable object that the function will iterate over.
2. A lambda, which the function calls for each element in the first argument. It can request one or two parameters.

$filtered_data = $data.filter |$parameter| { <PUPPET CODE BLOCK> }

or

$filtered_data = filter($data) |$parameter| { <PUPPET CODE BLOCK> }

When the first argument ($data in the above example) is an array, Puppet passes each value in turn to the lambda and returns an array containing the results.

# For the array $data, return an array containing the values that end with "berry"
$data = ["orange", "blueberry", "raspberry"]
$filtered_data = $data.filter |$items| { $items =~ /berry$/ }
# $filtered_data = [blueberry, raspberry]

When the first argument is a hash, Puppet passes each key and value pair to the lambda as an array in the form [key, value] and returns a hash containing the results.

# For the hash $data, return a hash containing all values of keys that end with "berry"
$data = { "orange" => 0, "blueberry" => 1, "raspberry" => 2 }
$filtered_data = $data.filter |$items| { $items[0] =~ /berry$/ }
# $filtered_data = {blueberry => 1, raspberry => 2}

When the first argument is an array and the lambda has two parameters, Puppet passes the
array's indexes (enumerated from 0) in the first parameter and its values in the second
parameter.

```puppet
# For the array $data, return an array of all keys that both end with "berry" and have
# an even-numbered index
$data = ["orange", "blueberry", "raspberry"]
$filtered_data = $data.filter |$indexes, $values| { $indexes % 2 == 0 and $values =~ /berry$/ }
# $filtered_data = [raspberry]

When the first argument is a hash, Puppet passes its keys to the first parameter and its values to the second parameter.

# For the hash $data, return a hash of all keys that both end with "berry" and have
# values less than or equal to 1
$data = { "orange" => 0, "blueberry" => 1, "raspberry" => 2 }
$filtered_data = $data.filter |$keys, $values| { $keys =~ /berry$/ and $values <= 1 }
# $filtered_data = {blueberry => 1}

find_file

• find_file(String *$paths)
  • Return type(s): Any.
• find_file(Array[String] *$paths_array)
  • Return type(s): Any.

Finds an existing file from a module and returns its path.

The argument to this function should be a String as a <MODULE NAME>/<FILE> reference, which will search for <FILE> relative to a module’s files directory. (For example, the reference mysql/mysqltuner.pl will search for the file <MODULES DIRECTORY>/mysql/files/mysqltuner.pl.)

This function can also accept:

• An absolute String path, which will check for the existence of a file from anywhere on disk.
• Multiple String arguments, which will return the path of the first file found, skipping non existing files.
• An array of string paths, which will return the path of the first file found from the given paths in the array, skipping non existing files.

The function returns undef if none of the given paths were found

flatten

• flatten(Any *$args)
  • Return type(s): Any.

Returns a flat Array produced from its possibly deeply nested given arguments.

One or more arguments of any data type can be given to this function. The result is always a flat array representation where any nested arrays are recursively flattened.

flatten(['a', ['b', ['c']]])
# Would return: ['a','b','c']

To flatten other kinds of iterables (for example hashes, or intermediate results like from a reverse_each) first convert the result to an array using Array($x), or $x.convert_to(Array). See the new function for details and options when performing a conversion.

$hsh = { a => 1, b => 2}

# -- without conversion
$hsh.flatten()
# Would return [{a => 1, b => 2}]

# -- with conversion
$hsh.convert_to(Array).flatten()
# Would return [a,1,b,2]

flatten(Array($hsh))
# Would also return [a,1,b,2]

$a1 = [1, [2, 3]]
$a2 = [[4,[5,6]]
$x = 7
flatten($a1, $a2, $x)
# would return [1,2,3,4,5,6,7]

flatten(42)
# Would return [42]

flatten([42])
# Would also return [42]

fqdn_rand

• fqdn_rand()
  • Return type(s): Any.

Usage: fqdn_rand(MAX, [SEED]). MAX is required and must be a positive integer; SEED is optional and may be any number or string.

Generates a random Integer number greater than or equal to 0 and less than MAX, combining the $fqdn fact and the value of SEED for repeatable randomness. (That is, each node will get a different random number from this function, but a given node’s result will be the same every time unless its hostname changes.)

This function is usually used for spacing out runs of resource-intensive cron tasks that run on many nodes, which could cause a thundering herd or degrade other services if they all fire at once. Adding a SEED can be useful when you have more than one such task and need several unrelated random numbers per node. (For example, fqdn_rand(30), fqdn_rand(30, 'expensive job 1'), and fqdn_rand(30, 'expensive job 2') will produce totally different numbers.)

generate

• generate()
  • Return type(s): Any.

Calls an external command on the Puppet master and returns the results of the command. Any arguments are passed to the external command as arguments. If the generator does not exit with return code of 0, the generator is considered to have failed and a parse error is thrown. Generators can only have file separators, alphanumerics, dashes, and periods in them. This function will attempt to protect you from malicious generator calls (e.g., those with ‘..’ in them), but it can never be entirely safe. No subshell is used to execute generators, so all shell metacharacters are passed directly to the generator.

hiera

• hiera()

Performs a standard priority lookup of the hierarchy and returns the most specific value for a given key. The returned value can be any type of data.

This function is deprecated in favor of the lookup function. While this function continues to work, it does not support:

• lookup_options stored in the data
• lookup across global, environment, and module layers

The function takes up to three arguments, in this order:

1. A string key that Hiera searches for in the hierarchy. Required.
2. An optional default value to return if Hiera doesn’t find anything matching the key.
   • If this argument isn’t provided and this function results in a lookup failure, Puppet fails with a compilation error.
3. The optional name of an arbitrary hierarchy level to insert at the top of the hierarchy. This lets you temporarily modify the hierarchy for a single lookup.
   • If Hiera doesn’t find a matching key in the overriding hierarchy level, it continues searching the rest of the hierarchy.

The hiera function does not find all matches throughout a hierarchy, instead returning the first specific value starting at the top of the hierarchy. To search throughout a hierarchy, use the hiera_array or hiera_hash functions.

# Assuming hiera.yaml
# :hierarchy:
#   - web01.example.com
#   - common

# Assuming web01.example.com.yaml:
# users:
#   - "Amy Barry"
#   - "Carrie Douglas"

# Assuming common.yaml:
users:
  admins:
    - "Edith Franklin"
    - "Ginny Hamilton"
  regular:
    - "Iris Jackson"
    - "Kelly Lambert"

# Assuming we are not web01.example.com:

$users = hiera('users', undef)

# $users contains {admins  => ["Edith Franklin", "Ginny Hamilton"],
#                  regular => ["Iris Jackson", "Kelly Lambert"]}

You can optionally generate the default value with a lambda that takes one parameter.

# Assuming the same Hiera data as the previous example:

$users = hiera('users') | $key | { "Key \'${key}\' not found" }

# $users contains {admins  => ["Edith Franklin", "Ginny Hamilton"],
#                  regular => ["Iris Jackson", "Kelly Lambert"]}
# If hiera couldn't match its key, it would return the lambda result,
# "Key 'users' not found".

The returned value’s data type depends on the types of the results. In the example above, Hiera matches the ‘users’ key and returns it as a hash.

See the ‘Using the lookup function’ documentation for how to perform lookup of data. Also see the ‘Using the deprecated hiera functions’ documentation for more information about the Hiera 3 functions.

hiera_array

• hiera_array()

Finds all matches of a key throughout the hierarchy and returns them as a single flattened array of unique values. If any of the matched values are arrays, they’re flattened and included in the results. This is called an array merge lookup.

This function is deprecated in favor of the lookup function. While this function continues to work, it does not support:

• lookup_options stored in the data
• lookup across global, environment, and module layers

The hiera_array function takes up to three arguments, in this order:

1. A string key that Hiera searches for in the hierarchy. Required.
2. An optional default value to return if Hiera doesn’t find anything matching the key.
   • If this argument isn’t provided and this function results in a lookup failure, Puppet fails with a compilation error.
3. The optional name of an arbitrary hierarchy level to insert at the top of the hierarchy. This lets you temporarily modify the hierarchy for a single lookup.
   • If Hiera doesn’t find a matching key in the overriding hierarchy level, it continues searching the rest of the hierarchy.

# Assuming hiera.yaml
# :hierarchy:
#   - web01.example.com
#   - common

# Assuming common.yaml:
# users:
#   - 'cdouglas = regular'
#   - 'efranklin = regular'

# Assuming web01.example.com.yaml:
# users: 'abarry = admin'

$allusers = hiera_array('users', undef)

# $allusers contains ["cdouglas = regular", "efranklin = regular", "abarry = admin"].

You can optionally generate the default value with a lambda that takes one parameter.

# Assuming the same Hiera data as the previous example:

$allusers = hiera_array('users') | $key | { "Key \'${key}\' not found" }

# $allusers contains ["cdouglas = regular", "efranklin = regular", "abarry = admin"].
# If hiera_array couldn't match its key, it would return the lambda result,
# "Key 'users' not found".

hiera_array expects that all values returned will be strings or arrays. If any matched value is a hash, Puppet raises a type mismatch error.

See the ‘Using the lookup function’ documentation for how to perform lookup of data. Also see the ‘Using the deprecated hiera functions’ documentation for more information about the Hiera 3 functions.

hiera_hash

• hiera_hash()

Finds all matches of a key throughout the hierarchy and returns them in a merged hash.

This function is deprecated in favor of the lookup function. While this function continues to work, it does not support:

• lookup_options stored in the data
• lookup across global, environment, and module layers

If any of the matched hashes share keys, the final hash uses the value from the highest priority match. This is called a hash merge lookup.

The merge strategy is determined by Hiera’s :merge_behavior setting.

The hiera_hash function takes up to three arguments, in this order:

1. A string key that Hiera searches for in the hierarchy. Required.
2. An optional default value to return if Hiera doesn’t find anything matching the key.
   • If this argument isn’t provided and this function results in a lookup failure, Puppet fails with a compilation error.
3. The optional name of an arbitrary hierarchy level to insert at the top of the hierarchy. This lets you temporarily modify the hierarchy for a single lookup.
   • If Hiera doesn’t find a matching key in the overriding hierarchy level, it continues searching the rest of the hierarchy.

# Assuming hiera.yaml
# :hierarchy:
#   - web01.example.com
#   - common

# Assuming common.yaml:
# users:
#   regular:
#     'cdouglas': 'Carrie Douglas'

# Assuming web01.example.com.yaml:
# users:
#   administrators:
#     'aberry': 'Amy Berry'

# Assuming we are not web01.example.com:

$allusers = hiera_hash('users', undef)

# $allusers contains {regular => {"cdouglas" => "Carrie Douglas"},
#                     administrators => {"aberry" => "Amy Berry"}}

You can optionally generate the default value with a lambda that takes one parameter.

# Assuming the same Hiera data as the previous example:

$allusers = hiera_hash('users') | $key | { "Key \'${key}\' not found" }

# $allusers contains {regular => {"cdouglas" => "Carrie Douglas"},
#                     administrators => {"aberry" => "Amy Berry"}}
# If hiera_hash couldn't match its key, it would return the lambda result,
# "Key 'users' not found".

hiera_hash expects that all values returned will be hashes. If any of the values found in the data sources are strings or arrays, Puppet raises a type mismatch error.

See the ‘Using the lookup function’ documentation for how to perform lookup of data. Also see the ‘Using the deprecated hiera functions’ documentation for more information about the Hiera 3 functions.

hiera_include

• hiera_include()

Assigns classes to a node using an array merge lookup that retrieves the value for a user-specified key from Hiera’s data.

This function is deprecated in favor of the lookup function in combination with include. While this function continues to work, it does not support:

• lookup_options stored in the data
• lookup across global, environment, and module layers

# In site.pp, outside of any node definitions and below any top-scope variables:
lookup('classes', Array[String], 'unique').include

The hiera_include function requires:

• A string key name to use for classes.
• A call to this function (i.e. hiera_include('classes')) in your environment’s sites.pp manifest, outside of any node definitions and below any top-scope variables that Hiera uses in lookups.
• classes keys in the appropriate Hiera data sources, with an array for each classes key and each value of the array containing the name of a class.

The function takes up to three arguments, in this order:

1. A string key that Hiera searches for in the hierarchy. Required.
2. An optional default value to return if Hiera doesn’t find anything matching the key.
   • If this argument isn’t provided and this function results in a lookup failure, Puppet fails with a compilation error.
3. The optional name of an arbitrary hierarchy level to insert at the top of the hierarchy. This lets you temporarily modify the hierarchy for a single lookup.
   • If Hiera doesn’t find a matching key in the overriding hierarchy level, it continues searching the rest of the hierarchy.

The function uses an array merge lookup to retrieve the classes array, so every node gets every class from the hierarchy.

# Assuming hiera.yaml
# :hierarchy:
#   - web01.example.com
#   - common

# Assuming web01.example.com.yaml:
# classes:
#   - apache::mod::php

# Assuming common.yaml:
# classes:
#   - apache

# In site.pp, outside of any node definitions and below any top-scope variables:
hiera_include('classes', undef)

# Puppet assigns the apache and apache::mod::php classes to the web01.example.com node.

You can optionally generate the default value with a lambda that takes one parameter.

# Assuming the same Hiera data as the previous example:

# In site.pp, outside of any node definitions and below any top-scope variables:
hiera_include('classes') | $key | {"Key \'${key}\' not found" }

# Puppet assigns the apache and apache::mod::php classes to the web01.example.com node.
# If hiera_include couldn't match its key, it would return the lambda result,
# "Key 'classes' not found".

See the ‘Using the lookup function’ documentation for how to perform lookup of data. Also see the ‘Using the deprecated hiera functions’ documentation for more information about the Hiera 3 functions.

hocon_data

• hocon_data(Struct[{path=>String[1]}] $options, Puppet::LookupContext $context)
  • Return type(s): Any.

The hocon_data is a hiera 5 data_hash data provider function. See the configuration guide documentation for how to use this function.

Note that this function is not supported without a hocon library being present.

import

• import(Any *$args)
  • Return type(s): Any.

The import function raises an error when called to inform the user that import is no longer supported.

include

• include(Any *$names)
  • Return type(s): Any.

Declares one or more classes, causing the resources in them to be evaluated and added to the catalog. Accepts a class name, an array of class names, or a comma-separated list of class names.

The include function can be used multiple times on the same class and will only declare a given class once. If a class declared with include has any parameters, Puppet will automatically look up values for them in Hiera, using <class name>::<parameter name> as the lookup key.

Contrast this behavior with resource-like class declarations (class {'name': parameter => 'value',}), which must be used in only one place per class and can directly set parameters. You should avoid using both include and resource-like declarations with the same class.

The include function does not cause classes to be contained in the class where they are declared. For that, see the contain function. It also does not create a dependency relationship between the declared class and the surrounding class; for that, see the require function.

You must use the class’s full name; relative names are not allowed. In addition to names in string form, you may also directly use Class and Resource Type-values that are produced by the resource and relationship expressions.

• Since < 3.0.0
• Since 4.0.0 support for class and resource type values, absolute names
• Since 4.7.0 returns an Array[Type[Class]] of all included classes

info

• info(Any *$values)
  • *values — The values to log.
  • Return type(s): Undef.

Logs a message on the server at level info.

inline_epp

• inline_epp(String $template, Optional[Hash[Pattern[/^\w+$/], Any]] $parameters)
  • Return type(s): Any.

Evaluates an Embedded Puppet (EPP) template string and returns the rendered text result as a String.

inline_epp('<EPP TEMPLATE STRING>', <PARAMETER HASH>)

The first argument to this function should be a string containing an EPP template. In most cases, the last argument is optional; if used, it should be a hash that contains parameters to pass to the template.

• See the template documentation for general template usage information.
• See the EPP syntax documentation for examples of EPP.

For example, to evaluate an inline EPP template and pass it the docroot and virtual_docroot parameters, call the inline_epp function like this:

inline_epp('docroot: <%= $docroot %> Virtual docroot: <%= $virtual_docroot %>', { 'docroot' => '/var/www/html', 'virtual_docroot' => '/var/www/example' })

Puppet produces a syntax error if you pass more parameters than are declared in the template’s parameter tag. When passing parameters to a template that contains a parameter tag, use the same names as the tag’s declared parameters.

Parameters are required only if they are declared in the called template’s parameter tag without default values. Puppet produces an error if the inline_epp function fails to pass any required parameter.

An inline EPP template should be written as a single-quoted string or heredoc. A double-quoted string is subject to expression interpolation before the string is parsed as an EPP template.

For example, to evaluate an inline EPP template using a heredoc, call the inline_epp function like this:

# Outputs 'Hello given argument planet!'
inline_epp(@(END), { x => 'given argument' })
<%- | $x, $y = planet | -%>
Hello <%= $x %> <%= $y %>!
END

inline_template

• inline_template()
  • Return type(s): Any.

Evaluate a template string and return its value. See the templating docs for more information. Note that if multiple template strings are specified, their output is all concatenated and returned as the output of the function.

join

• join(Array $arg, Optional[String] $delimiter)
  • Return type(s): Any.

Joins the values of an Array into a string with elements separated by a delimiter.

Supports up to two arguments

• values - first argument is required and must be an an Array
• delimiter - second arguments is the delimiter between elements, must be a String if given, and defaults to an empty string.

join(['a','b','c'], ",")
# Would result in: "a,b,c"

Note that array is flattened before elements are joined, but flattening does not extend to arrays nested in hashes or other objects.

$a = [1,2, undef, 'hello', [x,y,z], {a => 2, b => [3, 4]}]
notice join($a, ', ')

# would result in noticing:
# 1, 2, , hello, x, y, z, {"a"=>2, "b"=>[3, 4]}

For joining iterators and other containers of elements a conversion must first be made to an Array. The reason for this is that there are many options how such a conversion should be made.

[1,2,3].reverse_each.convert_to(Array).join(', ')
# would result in: "3, 2, 1"

{a => 1, b => 2}.convert_to(Array).join(', ')
# would result in "a, 1, b, 2"

For more detailed control over the formatting (including indentations and line breaks, delimiters around arrays and hash entries, between key/values in hash entries, and individual formatting of values in the array) see the new function for String and its formatting options for Array and Hash.

json_data

• json_data(Struct[{path=>String[1]}] $options, Puppet::LookupContext $context)
  • Return type(s): Any.

The json_data is a hiera 5 data_hash data provider function. See the configuration guide documentation for how to use this function.

keys

• keys(Hash $hsh)
  • Return type(s): Any.

Returns the keys of a hash as an Array

$hsh = {"apples" => 3, "oranges" => 4 }
$hsh.keys()
keys($hsh)
# both results in the array ["apples", "oranges"]

• Note that a hash in the puppet language accepts any data value (including undef) unless it is constrained with a Hash data type that narrows the allowed data types.
• For an empty hash, an empty array is returned.
• The order of the keys is the same as the order in the hash (typically the order in which they were added).

length

• length(Collection $arg)
  • Return type(s): Any.
• length(String $arg)
  • Return type(s): Any.
• length(Binary $arg)
  • Return type(s): Any.

Returns the length of an Array, Hash, String, or Binary value.

The returned value is a positive integer indicating the number of elements in the container; counting (possibly multibyte) characters for a String, bytes in a Binary, number of elements in an Array, and number of key-value associations in a Hash.

"roses".length()        # 5
length("violets")       # 7
[10, 20].length         # 2
{a => 1, b => 3}.length # 2

lest

• lest(Any $arg, Callable[0,0] &$block)
  • Return type(s): Any.

Calls a lambda without arguments if the value given to lest is undef. Returns the result of calling the lambda if the argument is undef, otherwise the given argument.

The lest function is useful in a chain of then calls, or in general as a guard against undef values. The function can be used to call fail, or to return a default value.

These two expressions are equivalent:

if $x == undef { do_things() }
lest($x) || { do_things() }

$data = {a => [ b, c ] }
notice $data.dig(a, b, c)
 .then |$x| { $x * 2 }
 .lest || { fail("no value for $data[a][b][c]" }

Would fail the operation because $data[a][b][c] results in undef (there is no b key in a).

In contrast - this example:

$data = {a => { b => { c => 10 } } }
notice $data.dig(a, b, c)
 .then |$x| { $x * 2 }
 .lest || { fail("no value for $data[a][b][c]" }

Would notice the value 20

lookup

• lookup(NameType $name, Optional[ValueType] $value_type, Optional[MergeType] $merge)
  • Return type(s): Any.
• lookup(NameType $name, Optional[ValueType] $value_type, Optional[MergeType] $merge, DefaultValueType $default_value)
  • Return type(s): Any.
• lookup(NameType $name, Optional[ValueType] $value_type, Optional[MergeType] $merge, BlockType &$block)
  • Return type(s): Any.
• lookup(OptionsWithName $options_hash, Optional[BlockType] &$block)
  • Return type(s): Any.
• lookup(Variant[String,Array[String]] $name, OptionsWithoutName $options_hash, Optional[BlockType] &$block)
  • Return type(s): Any.

Uses the Puppet lookup system to retrieve a value for a given key. By default, this returns the first value found (and fails compilation if no values are available), but you can configure it to merge multiple values into one, fail gracefully, and more.

When looking up a key, Puppet will search up to three tiers of data, in the following order:

1. Hiera.
2. The current environment’s data provider.
3. The indicated module’s data provider, if the key is of the form <MODULE NAME>::<SOMETHING>.

Arguments

You must provide the name of a key to look up, and can optionally provide other arguments. You can combine these arguments in the following ways:

• lookup( <NAME>, [<VALUE TYPE>], [<MERGE BEHAVIOR>], [<DEFAULT VALUE>] )
• lookup( [<NAME>], <OPTIONS HASH> )
• lookup( as above ) |$key| { # lambda returns a default value }

Arguments in [square brackets] are optional.

The arguments accepted by lookup are as follows:

1. <NAME> (string or array) — The name of the key to look up.
   • This can also be an array of keys. If Puppet doesn’t find anything for the first key, it will try again with the subsequent ones, only resorting to a default value if none of them succeed.
2. <VALUE TYPE> (data type) — A data type that must match the retrieved value; if not, the lookup (and catalog compilation) will fail. Defaults to Data (accepts any normal value).
3. <MERGE BEHAVIOR> (string or hash; see “Merge Behaviors” below) — Whether (and how) to combine multiple values. If present, this overrides any merge behavior specified in the data sources. Defaults to no value; Puppet will use merge behavior from the data sources if present, and will otherwise do a first-found lookup.
4. <DEFAULT VALUE> (any normal value) — If present, lookup returns this when it can’t find a normal value. Default values are never merged with found values. Like a normal value, the default must match the value type. Defaults to no value; if Puppet can’t find a normal value, the lookup (and compilation) will fail.
5. <OPTIONS HASH> (hash) — Alternate way to set the arguments above, plus some less-common extra options. If you pass an options hash, you can’t combine it with any regular arguments (except <NAME>). An options hash can have the following keys:
   • 'name' — Same as <NAME> (argument 1). You can pass this as an argument or in the hash, but not both.
   • 'value_type' — Same as <VALUE TYPE> (argument 2).
   • 'merge' — Same as <MERGE BEHAVIOR> (argument 3).
   • 'default_value' — Same as <DEFAULT VALUE> (argument 4).
   • 'default_values_hash' (hash) — A hash of lookup keys and default values. If Puppet can’t find a normal value, it will check this hash for the requested key before giving up. You can combine this with default_value or a lambda, which will be used if the key isn’t present in this hash. Defaults to an empty hash.
   • 'override' (hash) — A hash of lookup keys and override values. Puppet will check for the requested key in the overrides hash first; if found, it returns that value as the final value, ignoring merge behavior. Defaults to an empty hash.

Finally, lookup can take a lambda, which must accept a single parameter. This is yet another way to set a default value for the lookup; if no results are found, Puppet will pass the requested key to the lambda and use its result as the default value.

Merge Behaviors

Puppet lookup uses a hierarchy of data sources, and a given key might have values in multiple sources. By default, Puppet returns the first value it finds, but it can also continue searching and merge all the values together.

Note: Data sources can use the special lookup_options metadata key to request a specific merge behavior for a key. The lookup function will use that requested behavior unless you explicitly specify one.

The valid merge behaviors are:

• 'first' — Returns the first value found, with no merging. Puppet lookup’s default behavior.
• 'unique' (called “array merge” in classic Hiera) — Combines any number of arrays and scalar values to return a merged, flattened array with all duplicate values removed. The lookup will fail if any hash values are found.
• 'hash' — Combines the keys and values of any number of hashes to return a merged hash. If the same key exists in multiple source hashes, Puppet will use the value from the highest-priority data source; it won’t recursively merge the values.
• 'deep' — Combines the keys and values of any number of hashes to return a merged hash. If the same key exists in multiple source hashes, Puppet will recursively merge hash or array values (with duplicate values removed from arrays). For conflicting scalar values, the highest-priority value will win.
• {'strategy' => 'first'}, {'strategy' => 'unique'}, or {'strategy' => 'hash'} — Same as the string versions of these merge behaviors.
• {'strategy' => 'deep', <DEEP OPTION> => <VALUE>, ...} — Same as 'deep', but can adjust the merge with additional options. The available options are:
  • 'knockout_prefix' (string or undef) — A string prefix to indicate a value should be removed from the final result. If a value is exactly equal to the prefix, it will knockout the entire element. Defaults to undef, which disables this feature.
  • 'sort_merged_arrays' (boolean) — Whether to sort all arrays that are merged together. Defaults to false.
  • 'merge_hash_arrays' (boolean) — Whether to merge hashes within arrays. Defaults to false.

map

• map(Hash[Any, Any] $hash, Callable[2,2] &$block)
  • Return type(s): Any.
• map(Hash[Any, Any] $hash, Callable[1,1] &$block)
  • Return type(s): Any.
• map(Iterable $enumerable, Callable[2,2] &$block)
  • Return type(s): Any.
• map(Iterable $enumerable, Callable[1,1] &$block)
  • Return type(s): Any.

Applies a lambda to every value in a data structure and returns an array containing the results.

This function takes two mandatory arguments, in this order:

1. An array, hash, or other iterable object that the function will iterate over.
2. A lambda, which the function calls for each element in the first argument. It can request one or two parameters.

$transformed_data = $data.map |$parameter| { <PUPPET CODE BLOCK> }

or

$transformed_data = map($data) |$parameter| { <PUPPET CODE BLOCK> }

When the first argument ($data in the above example) is an array, Puppet passes each value in turn to the lambda.

# For the array $data, return an array containing each value multiplied by 10
$data = [1,2,3]
$transformed_data = $data.map |$items| { $items * 10 }
# $transformed_data contains [10,20,30]

When the first argument is a hash, Puppet passes each key and value pair to the lambda as an array in the form [key, value].

# For the hash $data, return an array containing the keys
$data = {'a'=>1,'b'=>2,'c'=>3}
$transformed_data = $data.map |$items| { $items[0] }
# $transformed_data contains ['a','b','c']

When the first argument is an array and the lambda has two parameters, Puppet passes the array’s indexes (enumerated from 0) in the first parameter and its values in the second parameter.

# For the array $data, return an array containing the indexes
$data = [1,2,3]
$transformed_data = $data.map |$index,$value| { $index }
# $transformed_data contains [0,1,2]

When the first argument is a hash, Puppet passes its keys to the first parameter and its values to the second parameter.

# For the hash $data, return an array containing each value
$data = {'a'=>1,'b'=>2,'c'=>3}
$transformed_data = $data.map |$key,$value| { $value }
# $transformed_data contains [1,2,3]

match

• match(String $string, Variant[Any, Type] $pattern)
  • Return type(s): Any.
• match(Array[String] $string, Variant[Any, Type] $pattern)
  • Return type(s): Any.

Matches a regular expression against a string and returns an array containing the match and any matched capturing groups.

The first argument is a string or array of strings. The second argument is either a regular expression, regular expression represented as a string, or Regex or Pattern data type that the function matches against the first argument.

The returned array contains the entire match at index 0, and each captured group at subsequent index values. If the value or expression being matched is an array, the function returns an array with mapped match results.

If the function doesn’t find a match, it returns ‘undef’.

$matches = "abc123".match(/[a-z]+[1-9]+/)
# $matches contains [abc123]

$matches = "abc123".match(/([a-z]+)([1-9]+)/)
# $matches contains [abc123, abc, 123]

$matches = ["abc123","def456"].match(/([a-z]+)([1-9]+)/)
# $matches contains [[abc123, abc, 123], [def456, def, 456]]

md5

• md5()
  • Return type(s): Any.

Returns a MD5 hash value from a provided string.

module_directory

• module_directory(String *$names)
  • Return type(s): Any.
• module_directory(Array[String] *$names)
  • Return type(s): Any.

Finds an existing module and returns the path to its root directory.

The argument to this function should be a module name String For example, the reference mysql will search for the directory <MODULES DIRECTORY>/mysql and return the first found on the modulepath.

This function can also accept:

• Multiple String arguments, which will return the path of the first module found, skipping non existing modules.
• An array of module names, which will return the path of the first module found from the given names in the array, skipping non existing modules.

The function returns undef if none of the given modules were found

new

• new(Type $type, Any *$args, Optional[Callable] &$block)
  • Return type(s): Any.

Creates a new instance/object of a given data type.

This function makes it possible to create new instances of concrete data types. If a block is given it is called with the just created instance as an argument.

Calling this function is equivalent to directly calling the data type:

$a = Integer.new("42")
$b = Integer("42")

These would both convert the string "42" to the decimal value 42.

$a = Integer.new("42", 8)
$b = Integer({from => "42", radix => 8})

This would convert the octal (radix 8) number "42" in string form to the decimal value 34.

The new function supports two ways of giving the arguments:

• by name (using a hash with property to value mapping)
• by position (as regular arguments)

Note that it is not possible to create new instances of some abstract data types (for example Variant). The data type Optional[T] is an exception as it will create an instance of T or undef if the value to convert is undef.

The arguments that can be given is determined by the data type.

An assertion is always made that the produced value complies with the given type constraints.

Integer[0].new("-100")

Would fail with an assertion error (since value is less than 0).

The following sections show the arguments and conversion rules per data type built into the Puppet Type System.

Conversion to Optional[T] and NotUndef[T]

Conversion to these data types is the same as a conversion to the type argument T. In the case of Optional[T] it is accepted that the argument to convert may be undef. It is however not acceptable to give other arguments (than undef) that cannot be converted to T.

Conversion to Integer

A new Integer can be created from Integer, Float, Boolean, and String values. For conversion from String it is possible to specify the radix (base).

type Radix = Variant[Default, Integer[2,2], Integer[8,8], Integer[10,10], Integer[16,16]]

function Integer.new(
  String $value,
  Radix $radix = 10,
  Boolean $abs = false
)

function Integer.new(
  Variant[Numeric, Boolean] $value,
  Boolean $abs = false
)

• When converting from String the default radix is 10.
• If radix is not specified an attempt is made to detect the radix from the start of the string:
  • 0b or 0B is taken as radix 2.
  • 0x or 0X is taken as radix 16.
  • 0 as radix 8.
  • All others are decimal.
• Conversion from String accepts an optional sign in the string.
• For hexadecimal (radix 16) conversion an optional leading “0x”, or “0X” is accepted.
• For octal (radix 8) an optional leading “0” is accepted.
• For binary (radix 2) an optional leading “0b” or “0B” is accepted.
• When radix is set to default, the conversion is based on the leading. characters in the string. A leading “0” for radix 8, a leading “0x”, or “0X” for radix 16, and leading “0b” or “0B” for binary.
• Conversion from Boolean results in 0 for false and 1 for true.
• Conversion from Integer, Float, and Boolean ignores the radix.
• Float value fractions are truncated (no rounding).
• When abs is set to true, the result will be an absolute integer.

$a_number = Integer("0xFF", 16)    # results in 255
$a_number = Integer("010")         # results in 8
$a_number = Integer("010", 10)     # results in 10
$a_number = Integer(true)          # results in 1
$a_number = Integer(-38, 10, true) # results in 38

Conversion to Float

A new Float can be created from Integer, Float, Boolean, and String values. For conversion from String both float and integer formats are supported.

function Float.new(
  Variant[Numeric, Boolean, String] $value,
  Boolean $abs = true
)

• For an integer, the floating point fraction of .0 is added to the value.
• A Boolean true is converted to 1.0, and a false to 0.0
• In String format, integer prefixes for hex and binary are understood (but not octal since floating point in string format may start with a ‘0’).
• When abs is set to true, the result will be an absolute floating point value.

Conversion to Numeric

A new Integer or Float can be created from Integer, Float, Boolean and String values.

function Numeric.new(
  Variant[Numeric, Boolean, String] $value,
  Boolean $abs = true
)

• If the value has a decimal period, or if given in scientific notation (e/E), the result is a Float, otherwise the value is an Integer. The conversion from String always uses a radix based on the prefix of the string.
• Conversion from Boolean results in 0 for false and 1 for true.
• When abs is set to true, the result will be an absolute Floator Integer value.

$a_number = Numeric(true)        # results in 1
$a_number = Numeric("0xFF")      # results in 255
$a_number = Numeric("010")       # results in 8
$a_number = Numeric("3.14")      # results in 3.14 (a float)
$a_number = Numeric(-42.3, true) # results in 42.3
$a_number = Numeric(-42, true)   # results in 42

Conversion to Timespan

A new Timespan can be created from Integer, Float, String, and Hash values. Several variants of the constructor are provided.

Timespan from seconds

When a Float is used, the decimal part represents fractions of a second.

function Timespan.new(
  Variant[Float, Integer] $value
)

Timespan from days, hours, minutes, seconds, and fractions of a second

The arguments can be passed separately in which case the first four, days, hours, minutes, and seconds are mandatory and the rest are optional. All values may overflow and/or be negative. The internal 128-bit nano-second integer is calculated as:

(((((days * 24 + hours) * 60 + minutes) * 60 + seconds) * 1000 + milliseconds) * 1000 + microseconds) * 1000 + nanoseconds

function Timespan.new(
  Integer $days, Integer $hours, Integer $minutes, Integer $seconds,
  Integer $milliseconds = 0, Integer $microseconds = 0, Integer $nanoseconds = 0
)

or, all arguments can be passed as a Hash, in which case all entries are optional:

function Timespan.new(
  Struct[{
    Optional[negative] => Boolean,
    Optional[days] => Integer,
    Optional[hours] => Integer,
    Optional[minutes] => Integer,
    Optional[seconds] => Integer,
    Optional[milliseconds] => Integer,
    Optional[microseconds] => Integer,
    Optional[nanoseconds] => Integer
  }] $hash
)

Timespan from String and format directive patterns

The first argument is parsed using the format optionally passed as a string or array of strings. When an array is used, an attempt will be made to parse the string using the first entry and then with each entry in succession until parsing succeeds. If the second argument is omitted, an array of default formats will be used.

An exception is raised when no format was able to parse the given string.

function Timespan.new(
  String $string, Variant[String[2],Array[String[2], 1]] $format = <default format>)
)

the arguments may also be passed as a Hash:

function Timespan.new(
  Struct[{
    string => String[1],
    Optional[format] => Variant[String[2],Array[String[2], 1]]
  }] $hash
)

The directive consists of a percent (%) character, zero or more flags, optional minimum field width and a conversion specifier as follows:

%[Flags][Width]Conversion

Flags:

Format directives:

The format directive that represents the highest magnitude in the format will be allowed to overflow. I.e. if no “%D” is used but a “%H” is present, then the hours may be more than 23.

The default array contains the following patterns:

['%D-%H:%M:%S', '%D-%H:%M', '%H:%M:%S', '%H:%M']

Examples - Converting to Timespan

$duration = Timespan(13.5)       # 13 seconds and 500 milliseconds
$duration = Timespan({days=>4})  # 4 days
$duration = Timespan(4, 0, 0, 2) # 4 days and 2 seconds
$duration = Timespan('13:20')    # 13 hours and 20 minutes (using default pattern)
$duration = Timespan('10:03.5', '%M:%S.%L') # 10 minutes, 3 seconds, and 5 milli-seconds
$duration = Timespan('10:03.5', '%M:%S.%N') # 10 minutes, 3 seconds, and 5 nano-seconds

Conversion to Timestamp

A new Timestamp can be created from Integer, Float, String, and Hash values. Several variants of the constructor are provided.

Timestamp from seconds since epoch (1970-01-01 00:00:00 UTC)

When a Float is used, the decimal part represents fractions of a second.

function Timestamp.new(
  Variant[Float, Integer] $value
)

Timestamp from String and patterns consisting of format directives

The first argument is parsed using the format optionally passed as a string or array of strings. When an array is used, an attempt will be made to parse the string using the first entry and then with each entry in succession until parsing succeeds. If the second argument is omitted, an array of default formats will be used.

A third optional timezone argument can be provided. The first argument will then be parsed as if it represents a local time in that timezone. The timezone can be any timezone that is recognized when using the ‘%z’ or ‘%Z’ formats, or the word ‘current’, in which case the current timezone of the evaluating process will be used. The timezone argument is case insensitive.

The default timezone, when no argument is provided, or when using the keyword default, is ‘UTC’.

It is illegal to provide a timezone argument other than default in combination with a format that contains ‘%z’ or ‘%Z’ since that would introduce an ambiguity as to which timezone to use. The one extracted from the string, or the one provided as an argument.

An exception is raised when no format was able to parse the given string.

function Timestamp.new(
  String $string,
  Variant[String[2],Array[String[2], 1]] $format = <default format>,
  String $timezone = default)
)

the arguments may also be passed as a Hash:

function Timestamp.new(
  Struct[{
    string => String[1],
    Optional[format] => Variant[String[2],Array[String[2], 1]],
    Optional[timezone] => String[1]
  }] $hash
)

The directive consists of a percent (%) character, zero or more flags, optional minimum field width and a conversion specifier as follows:

%[Flags][Width]Conversion

Flags:

Format directives (names and padding can be altered using flags):

Date (Year, Month, Day):

Time (Hour, Minute, Second, Subsecond):

Time (Hour, Minute, Second, Subsecond):

Weekday:

ISO 8601 week-based year and week number:

The first week of YYYY starts with a Monday and includes YYYY-01-04. The days in the year before the first week are in the last week of the previous year.

Week number:

The first week of YYYY that starts with a Sunday or Monday (according to %U or %W). The days in the year before the first week are in week 0.

Seconds since the Epoch:

Literal string:

Combination:

The default array contains the following patterns:

When a timezone argument (other than default) is explicitly provided:

['%FT%T.L', '%FT%T', '%F']

otherwise:

['%FT%T.%L %Z', '%FT%T %Z', '%F %Z', '%FT%T.L', '%FT%T', '%F']

Examples - Converting to Timestamp

$ts = Timestamp(1473150899)                              # 2016-09-06 08:34:59 UTC
$ts = Timestamp({string=>'2015', format=>'%Y'})          # 2015-01-01 00:00:00.000 UTC
$ts = Timestamp('Wed Aug 24 12:13:14 2016', '%c')        # 2016-08-24 12:13:14 UTC
$ts = Timestamp('Wed Aug 24 12:13:14 2016 PDT', '%c %Z') # 2016-08-24 19:13:14.000 UTC
$ts = Timestamp('2016-08-24 12:13:14', '%F %T', 'PST')   # 2016-08-24 20:13:14.000 UTC
$ts = Timestamp('2016-08-24T12:13:14', default, 'PST')   # 2016-08-24 20:13:14.000 UTC

Conversion to Type

A new Type can be create from its String representation.

$t = Type.new('Integer[10]')

Conversion to String

Conversion to String is the most comprehensive conversion as there are many use cases where a string representation is wanted. The defaults for the many options have been chosen with care to be the most basic “value in textual form” representation. The more advanced forms of formatting are intended to enable writing special purposes formatting functions in the Puppet language.

A new string can be created from all other data types. The process is performed in several steps - first the data type of the given value is inferred, then the resulting data type is used to find the most significant format specified for that data type. And finally, the found format is used to convert the given value.

The mapping from data type to format is referred to as the format map. This map allows different formatting depending on type.

$format_map = {
  Integer[default, 0] => "%d",
  Integer[1, default] => "%#x"
}
String("-1", $format_map)  # produces '-1'
String("10", $format_map)  # produces '0xa'

A format is specified on the form:

%[Flags][Width][.Precision]Format

Width is the number of characters into which the value should be fitted. This allocated space is padded if value is shorter. By default it is space padded, and the flag 0 will cause padding with 0 for numerical formats.

Precision is the number of fractional digits to show for floating point, and the maximum characters included in a string format.

Note that all data type supports the formats s and p with the meaning “default string representation” and “default programmatic string representation” (which for example means that a String is quoted in ‘p’ format).

Signatures of String conversion

type Format = Pattern[/^%([\s\+\-#0\[\{<\(\|]*)([1-9][0-9]*)?(?:\.([0-9]+))?([a-zA-Z])/]
type ContainerFormat = Struct[{
  format         => Optional[String],
  separator      => Optional[String],
  separator2     => Optional[String],
  string_formats => Hash[Type, Format]
  }]
type TypeMap = Hash[Type, Variant[Format, ContainerFormat]]
type Formats = Variant[Default, String[1], TypeMap]

function String.new(
  Any $value,
  Formats $string_formats
)

Where:

• separator is the string used to separate entries in an array, or hash (extra space should not be included at the end), defaults to ","
• separator2 is the separator between key and value in a hash entry (space padding should be included as wanted), defaults to " => ".
• string_formats is a data type to format map for values contained in arrays and hashes - defaults to {Any => "%p"}. Note that these nested formats are not applicable to data types that are containers; they are always formatted as per the top level format specification.

$str = String(10)      # produces '10'
$str = String([10])    # produces '["10"]'

$str = String(10, "%#x")    # produces '0x10'
$str = String([10], "%(a")  # produces '("10")'

$formats = {
  Array => {
    format => '%(a',
    string_formats => { Integer => '%#x' }
  }
}
$str = String([1,2,3], $formats) # produces '(0x1, 0x2, 0x3)'

The given formats are merged with the default formats, and matching of values to convert against format is based on the specificity of the mapped type; for example, different formats can be used for short and long arrays.

Integer to String

Defaults to d.

Float to String

Defaults to p.

String to String

Defaults to s at top level and p inside array or hash.

Boolean to String

Regexp to String

Undef to String

Default value to String

Binary value to String

• The alternate form flag # will quote the binary or base64 text output.
• The format %#s allows invalid UTF-8 characters and outputs all non ascii bytes as hex escaped characters on the form \\xHH where H is a hex digit.
• The width and precision values are applied to the text part only in %p format.

Array & Tuple to String

See “Flags” <[({\| for formatting of delimiters, and “Additional parameters for containers; Array and Hash” for more information about options.

The alternate form flag # will cause indentation of nested array or hash containers. If width is also set it is taken as the maximum allowed length of a sequence of elements (not including delimiters). If this max length is exceeded, each element will be indented.

Hash & Struct to String

See “Flags” <[({\| for formatting of delimiters, and “Additional parameters for containers; Array and Hash” for more information about options.

The alternate form flag # will format each hash key/value entry indented on a separate line.

Type to String

Flags

Conversion to Boolean

Accepts a single value as argument:

• Float 0.0 is false, all other float values are true
• Integer 0 is false, all other integer values are true
• Strings
  • true if ‘true’, ‘yes’, ‘y’ (case independent compare)
  • false if ‘false’, ‘no’, ‘n’ (case independent compare)
• Boolean is already boolean and is simply returned

Conversion to Array and Tuple

When given a single value as argument:

• A non empty Hash is converted to an array matching Array[Tuple[Any,Any], 1].
• An empty Hash becomes an empty array.
• An Array is simply returned.
• An Iterable[T] is turned into an array of T instances.
• A Binary is converted to an Array[Integer[0,255]] of byte values

When given a second Boolean argument:

• if true, a value that is not already an array is returned as a one element array.
• if false, (the default), converts the first argument as shown above.

$arr = Array($value, true)

Conversion to a Tuple works exactly as conversion to an Array, only that the constructed array is asserted against the given tuple type.

Conversion to Hash and Struct

Accepts a single value as argument:

• An empty Array becomes an empty Hash
• An Array matching Array[Tuple[Any,Any], 1] is converted to a hash where each tuple describes a key/value entry
• An Array with an even number of entries is interpreted as [key1, val1, key2, val2, ...]
• An Iterable is turned into an Array and then converted to hash as per the array rules
• A Hash is simply returned

Alternatively, a tree can be constructed by giving two values; an array of tuples on the form [path, value] (where the path is the path from the root of a tree, and value the value at that position in the tree), and either the option 'tree' (do not convert arrays to hashes except the top level), or 'hash_tree' (convert all arrays to hashes).

The tree/hash_tree forms of Hash creation are suited for transforming the result of an iteration using tree_each and subsequent filtering or mapping.

Mapping an arbitrary structure in a way that keeps the structure, but where some values are replaced can be done by using the tree_each function, mapping, and then constructing a new Hash from the result:

# A hash tree with 'water' at different locations
$h = { a => { b => { x => 'water'}}, b => { y => 'water'} }
# a helper function that turns water into wine
function make_wine($x) { if $x == 'water' { 'wine' } else { $x } }
# create a flattened tree with water turned into wine
$flat_tree = $h.tree_each.map |$entry| { [$entry[0], make_wine($entry[1])] }
# create a new Hash and log it
notice Hash($flat_tree, 'hash_tree')

Would notice the hash {a => {b => {x => wine}}, b => {y => wine}}

Conversion to a Struct works exactly as conversion to a Hash, only that the constructed hash is asserted against the given struct type.

Conversion to a Regexp

A String can be converted into a Regexp

Example: Converting a String into a Regexp

$s = '[a-z]+\.com'
$r = Regexp($s)
if('foo.com' =~ $r) {
  ...
}

Creating a SemVer

A SemVer object represents a single Semantic Version. It can be created from a String, individual values for its parts, or a hash specifying the value per part. See the specification at semver.org for the meaning of the SemVer’s parts.

The signatures are:

type PositiveInteger = Integer[0,default]
type SemVerQualifier = Pattern[/\A(?<part>[0-9A-Za-z-]+)(?:\.\g<part>)*\Z/]
type SemVerString = String[1]
type SemVerHash =Struct[{
  major                => PositiveInteger,
  minor                => PositiveInteger,
  patch                => PositiveInteger,
  Optional[prerelease] => SemVerQualifier,
  Optional[build]      => SemVerQualifier
}]

function SemVer.new(SemVerString $str)

function SemVer.new(
        PositiveInteger           $major
        PositiveInteger           $minor
        PositiveInteger           $patch
        Optional[SemVerQualifier] $prerelease = undef
        Optional[SemVerQualifier] $build = undef
        )

function SemVer.new(SemVerHash $hash_args)

# As a type, SemVer can describe disjunct ranges which versions can be
# matched against - here the type is constructed with two
# SemVerRange objects.
#
$t = SemVer[
  SemVerRange('>=1.0.0 <2.0.0'),
  SemVerRange('>=3.0.0 <4.0.0')
]
notice(SemVer('1.2.3') =~ $t) # true
notice(SemVer('2.3.4') =~ $t) # false
notice(SemVer('3.4.5') =~ $t) # true

Creating a SemVerRange

A SemVerRange object represents a range of SemVer. It can be created from a String, or from two SemVer instances, where either end can be given as a literal default to indicate infinity. The string format of a SemVerRange is specified by the Semantic Version Range Grammar.

Use of the comparator sets described in the grammar (joining with ||) is not supported.

The signatures are:

type SemVerRangeString = String[1]
type SemVerRangeHash = Struct[{
  min                   => Variant[Default, SemVer],
  Optional[max]         => Variant[Default, SemVer],
  Optional[exclude_max] => Boolean
}]

function SemVerRange.new(
  SemVerRangeString $semver_range_string
)

function SemVerRange.new(
  Variant[Default,SemVer] $min
  Variant[Default,SemVer] $max
  Optional[Boolean]       $exclude_max = undef
)

function SemVerRange.new(
  SemVerRangeHash $semver_range_hash
)

For examples of SemVerRange use see “Creating a SemVer”

Creating a Binary

A Binary object represents a sequence of bytes and it can be created from a String in Base64 format, an Array containing byte values. A Binary can also be created from a Hash containing the value to convert to a Binary.

The signatures are:

type ByteInteger = Integer[0,255]
type Base64Format = Enum["%b", "%u", "%B", "%s"]
type StringHash = Struct[{value => String, "format" => Optional[Base64Format]}]
type ArrayHash = Struct[{value => Array[ByteInteger]}]
type BinaryArgsHash = Variant[StringHash, ArrayHash]

function Binary.new(
  String $base64_str,
  Optional[Base64Format] $format
)


function Binary.new(
  Array[ByteInteger] $byte_array
}

# Same as for String, or for Array, but where arguments are given in a Hash.
function Binary.new(BinaryArgsHash $hash_args)

The formats have the following meaning:

• The default format is %B.
• Note that the format %r should be used sparingly, or not at all. It exists for backwards compatibility reasons when someone receiving a string from some function and that string should be treated as Binary. Such code should be changed to return a Binary instead of a String.

# create the binary content "abc"
$a = Binary('YWJj')

# create the binary content from content in a module's file
$b = binary_file('mymodule/mypicture.jpg')

• Since 4.5.0
• Binary type since 4.8.0

Creating an instance of a Type using the Init type.

The type Init[T] describes a value that can be used when instantiating a type. When used as the first argument in a call to new, it will dispatch the call to its contained type and optionally augment the parameter list with additional arguments.

# The following declaration
$x = Init[Integer].new('128')
# is exactly the same as
$x = Integer.new('128')

or, with base 16 and using implicit new

# The following declaration
$x = Init[Integer,16]('80')
# is exactly the same as
$x = Integer('80', 16)

$fmt = Init[String,'%#x']
notice($fmt(256)) # will notice '0x100'

next

• next(Optional[Any] $value)
  • Return type(s): Any.

Makes iteration continue with the next value, optionally with a given value for this iteration. If a value is not given it defaults to undef

notice

• notice(Any *$values)
  • *values — The values to log.
  • Return type(s): Undef.

Logs a message on the server at level notice.

realize

• realize()
  • Return type(s): Any.

Make a virtual object real. This is useful when you want to know the name of the virtual object and don’t want to bother with a full collection. It is slightly faster than a collection, and, of course, is a bit shorter. You must pass the object using a reference; e.g.: realize User[luke].

reduce

• reduce(Iterable $enumerable, Callable[2,2] &$block)
  • Return type(s): Any.
• reduce(Iterable $enumerable, Any $memo, Callable[2,2] &$block)
  • Return type(s): Any.

Applies a lambda to every value in a data structure from the first argument, carrying over the returned value of each iteration, and returns the result of the lambda’s final iteration. This lets you create a new value or data structure by combining values from the first argument’s data structure.

This function takes two mandatory arguments, in this order:

1. An array, hash, or other iterable object that the function will iterate over.
2. A lambda, which the function calls for each element in the first argument. It takes two mandatory parameters:
   1. A memo value that is overwritten after each iteration with the iteration’s result.
   2. A second value that is overwritten after each iteration with the next value in the function’s first argument.

$data.reduce |$memo, $value| { ... }

or

reduce($data) |$memo, $value| { ... }

You can also pass an optional “start memo” value as an argument, such as start below:

$data.reduce(start) |$memo, $value| { ... }

or

reduce($data, start) |$memo, $value| { ... }

When the first argument ($data in the above example) is an array, Puppet passes each of the data structure’s values in turn to the lambda’s parameters. When the first argument is a hash, Puppet converts each of the hash’s values to an array in the form [key, value].

If you pass a start memo value, Puppet executes the lambda with the provided memo value and the data structure’s first value. Otherwise, Puppet passes the structure’s first two values to the lambda.

Puppet calls the lambda for each of the data structure’s remaining values. For each call, it passes the result of the previous call as the first parameter ($memo in the above examples) and the next value from the data structure as the second parameter ($value).

# Reduce the array $data, returning the sum of all values in the array.
$data = [1, 2, 3]
$sum = $data.reduce |$memo, $value| { $memo + $value }
# $sum contains 6

# Reduce the array $data, returning the sum of a start memo value and all values in the
# array.
$data = [1, 2, 3]
$sum = $data.reduce(4) |$memo, $value| { $memo + $value }
# $sum contains 10

# Reduce the hash $data, returning the sum of all values and concatenated string of all
# keys.
$data = {a => 1, b => 2, c => 3}
$combine = $data.reduce |$memo, $value| {
  $string = "${memo[0]}${value[0]}"
  $number = $memo[1] + $value[1]
  [$string, $number]
}
# $combine contains [abc, 6]

# Reduce the array $data, returning the sum of all values in the array and starting
# with $memo set to an arbitrary value instead of $data's first value.
$data = [1, 2, 3]
$sum = $data.reduce(4) |$memo, $value| { $memo + $value }
# At the start of the lambda's first iteration, $memo contains 4 and $value contains 1.
# After all iterations, $sum contains 10.

# Reduce the hash $data, returning the sum of all values and concatenated string of
# all keys, and starting with $memo set to an arbitrary array instead of $data's first
# key-value pair.
$data = {a => 1, b => 2, c => 3}
$combine = $data.reduce( [d, 4] ) |$memo, $value| {
  $string = "${memo[0]}${value[0]}"
  $number = $memo[1] + $value[1]
  [$string, $number]
}
# At the start of the lambda's first iteration, $memo contains [d, 4] and $value
# contains [a, 1].
# $combine contains [dabc, 10]

# Reduce a hash of hashes $data, merging defaults into the inner hashes.
$data = {
  'connection1' => {
    'username' => 'user1',
    'password' => 'pass1',
  },
  'connection_name2' => {
    'username' => 'user2',
    'password' => 'pass2',
  },
}

$defaults = {
  'maxActive' => '20',
  'maxWait'   => '10000',
  'username'  => 'defaultuser',
  'password'  => 'defaultpass',
}

$merged = $data.reduce( {} ) |$memo, $x| {
  $memo + { $x[0] => $defaults + $data[$x[0]] }
}
# At the start of the lambda's first iteration, $memo is set to {}, and $x is set to
# the first [key, value] tuple. The key in $data is, therefore, given by $x[0]. In
# subsequent rounds, $memo retains the value returned by the expression, i.e.
# $memo + { $x[0] => $defaults + $data[$x[0]] }.

regsubst

• regsubst(Variant[Array[String],String] $target, String $pattern, Variant[String,Hash[String,String]] $replacement, Optional[Optional[Pattern[/^[GEIM]*$/]]] $flags, Optional[Enum['N','E','S','U']] $encoding)
  • Return type(s): Any.
• regsubst(Variant[Array[String],String] $target, Variant[Regexp,Type[Regexp]] $pattern, Variant[String,Hash[String,String]] $replacement, Optional[Pattern[/^G?$/]] $flags)
  • Return type(s): Any.

Performs regexp replacement on a string or array of strings.

$i3 = regsubst($ipaddress,'^(\\d+)\\.(\\d+)\\.(\\d+)\\.(\\d+)$','\\3')

$x = regsubst($ipaddress, /([0-9]+)/, '<\\1>', 'G')

require

• require(Any *$names)
  • Return type(s): Any.

Requires the specified classes. Evaluate one or more classes, adding the required class as a dependency.

The relationship metaparameters work well for specifying relationships between individual resources, but they can be clumsy for specifying relationships between classes. This function is a superset of the ‘include’ function, adding a class relationship so that the requiring class depends on the required class.

Warning: using require in place of include can lead to unwanted dependency cycles.

For instance the following manifest, with ‘require’ instead of ‘include’ would produce a nasty dependence cycle, because notify imposes a before between File[/foo] and Service[foo]:

class myservice {
  service { foo: ensure => running }
}

class otherstuff {
   include myservice
   file { '/foo': notify => Service[foo] }
}

Note that this function only works with clients 0.25 and later, and it will fail if used with earlier clients.

You must use the class’s full name; relative names are not allowed. In addition to names in string form, you may also directly use Class and Resource Type values that are produced when evaluating resource and relationship expressions.

• Since 4.0.0 Class and Resource types, absolute names
• Since 4.7.0 Returns an Array[Type[Class]] with references to the required classes

return

• return(Optional[Any] $value)
  • Return type(s): Any.

Makes iteration continue with the next value, optionally with a given value for this iteration. If a value is not given it defaults to undef

reverse_each

• reverse_each(Iterable $iterable)
  • Return type(s): Any.
• reverse_each(Iterable $iterable, Callable[1,1] &$block)
  • Return type(s): Any.

Reverses the order of the elements of something that is iterable and optionally runs a lambda for each element.

This function takes one to two arguments:

1. An Iterable that the function will iterate over.
2. An optional lambda, which the function calls for each element in the first argument. It must request one parameter.

$data.reverse_each |$parameter| { <PUPPET CODE BLOCK> }

or

$reverse_data = $data.reverse_each

or

reverse_each($data) |$parameter| { <PUPPET CODE BLOCK> }

or

$reverse_data = reverse_each($data)

When no second argument is present, Puppet returns an Iterable that represents the reverse order of its first argument. This allows methods on Iterable to be chained.

When a lambda is given as the second argument, Puppet iterates the first argument in reverse order and passes each value in turn to the lambda, then returns undef.

# Puppet will log a notice for each of the three items
# in $data in reverse order.
$data = [1,2,3]
$data.reverse_each |$item| { notice($item) }

When no second argument is present, Puppet returns a new Iterable which allows it to be directly chained into another function that takes an Iterable as an argument.

# For the array $data, return an array containing each
# value multiplied by 10 in reverse order
$data = [1,2,3]
$transformed_data = $data.reverse_each.map |$item| { $item * 10 }
# $transformed_data is set to [30,20,10]

# For the array $data, return an array containing each
# value multiplied by 10 in reverse order
$data = [1,2,3]
$transformed_data = map(reverse_each($data)) |$item| { $item * 10 }
# $transformed_data is set to [30,20,10]

scanf

• scanf(String $data, String $format, Optional[Callable] &$block)
  • Return type(s): Any.

Scans a string and returns an array of one or more converted values based on the given format string. See the documentation of Ruby’s String#scanf method for details about the supported formats (which are similar but not identical to the formats used in Puppet’s sprintf function.)

This function takes two mandatory arguments: the first is the string to convert, and the second is the format string. The result of the scan is an array, with each successfully scanned and transformed value. The scanning stops if a scan is unsuccessful, and the scanned result up to that point is returned. If there was no successful scan, the result is an empty array.

“42”.scanf(“%i”)

You can also optionally pass a lambda to scanf, to do additional validation or processing.

"42".scanf("%i") |$x| {
  unless $x[0] =~ Integer {
    fail "Expected a well formed integer value, got '$x[0]'"
  }
  $x[0]
}

sha1

• sha1()
  • Return type(s): Any.

Returns a SHA1 hash value from a provided string.

sha256

• sha256()
  • Return type(s): Any.

Returns a SHA256 hash value from a provided string.

shellquote

• shellquote()
  • Return type(s): Any.

Quote and concatenate arguments for use in Bourne shell.

Each argument is quoted separately, and then all are concatenated with spaces. If an argument is an array, the elements of that array is interpolated within the rest of the arguments; this makes it possible to have an array of arguments and pass that array to shellquote instead of having to specify each argument individually in the call.

slice

• slice(Hash[Any, Any] $hash, Integer[1, default] $slice_size, Optional[Callable] &$block)
  • Return type(s): Any.
• slice(Iterable $enumerable, Integer[1, default] $slice_size, Optional[Callable] &$block)
  • Return type(s): Any.

Slices an array or hash into pieces of a given size.

This function takes two mandatory arguments: the first should be an array or hash, and the second specifies the number of elements to include in each slice.

When the first argument is a hash, each key value pair is counted as one. For example, a slice size of 2 will produce an array of two arrays with key, and value.

$a.slice(2) |$entry|          { notice "first ${$entry[0]}, second ${$entry[1]}" }
$a.slice(2) |$first, $second| { notice "first ${first}, second ${second}" }

The function produces a concatenated result of the slices.

slice([1,2,3,4,5,6], 2) # produces [[1,2], [3,4], [5,6]]
slice(Integer[1,6], 2)  # produces [[1,2], [3,4], [5,6]]
slice(4,2)              # produces [[0,1], [2,3]]
slice('hello',2)        # produces [[h, e], [l, l], [o]]

 $a.slice($n) |$x| { ... }
 slice($a) |$x| { ... }

The lambda should have either one parameter (receiving an array with the slice), or the same number of parameters as specified by the slice size (each parameter receiving its part of the slice). If there are fewer remaining elements than the slice size for the last slice, it will contain the remaining elements. If the lambda has multiple parameters, excess parameters are set to undef for an array, or to empty arrays for a hash.

    $a.slice(2) |$first, $second| { ... }

split

• split(String $str, String $pattern)
  • Return type(s): Any.
• split(String $str, Regexp $pattern)
  • Return type(s): Any.
• split(String $str, Type[Regexp] $pattern)
  • Return type(s): Any.

Splits a string into an array using a given pattern. The pattern can be a string, regexp or regexp type.

$string     = 'v1.v2:v3.v4'
$array_var1 = split($string, /:/)
$array_var2 = split($string, '[.]')
$array_var3 = split($string, Regexp['[.:]'])

#`$array_var1` now holds the result `['v1.v2', 'v3.v4']`,
# while `$array_var2` holds `['v1', 'v2:v3', 'v4']`, and
# `$array_var3` holds `['v1', 'v2', 'v3', 'v4']`.

Note that in the second example, we split on a literal string that contains a regexp meta-character (.), which must be escaped. A simple way to do that for a single character is to enclose it in square brackets; a backslash will also escape a single character.

sprintf

• sprintf()
  • Return type(s): Any.

Perform printf-style formatting of text.

The first parameter is format string describing how the rest of the parameters should be formatted. See the documentation for the Kernel::sprintf function in Ruby for all the details.

step

• step(Iterable $iterable, Integer[1] $step)
  • Return type(s): Any.
• step(Iterable $iterable, Integer[1] $step, Callable[1,1] &$block)
  • Return type(s): Any.

When no block is given, Puppet returns a new Iterable which allows it to be directly chained into another function that takes an Iterable as an argument.

# For the array $data, return an array, set to the first element and each 5th successor element, in reverse
# order multiplied by 10
$data = Integer[0,20]
$transformed_data = $data.step(5).map |$item| { $item * 10 }
$transformed_data contains [0,50,100,150,200]

# For the array $data, return an array, set to the first and each 5th
# successor, in reverse order, multiplied by 10
$data = Integer[0,20]
$transformed_data = map(step($data, 5)) |$item| { $item * 10 }
$transformed_data contains [0,50,100,150,200]

strftime

• strftime(Timespan $time_object, String $format)
  • Return type(s): Any.
• strftime(Timestamp $time_object, String $format, Optional[String] $timezone)
  • Return type(s): Any.
• strftime(String $format, Optional[String] $timezone)
  • Return type(s): Any.

Formats timestamp or timespan according to the directives in the given format string. The directives begins with a percent (%) character. Any text not listed as a directive will be passed through to the output string.

A third optional timezone argument can be provided. The first argument will then be formatted to represent a local time in that timezone. The timezone can be any timezone that is recognized when using the ‘%z’ or ‘%Z’ formats, or the word ‘current’, in which case the current timezone of the evaluating process will be used. The timezone argument is case insensitive.

The default timezone, when no argument is provided, or when using the keyword default, is ‘UTC’.

The directive consists of a percent (%) character, zero or more flags, optional minimum field width and a conversion specifier as follows:

%[Flags][Width]Conversion

Flags that controls padding

Timestamp specific flags

Format directives applicable to Timestamp (names and padding can be altered using flags):

Date (Year, Month, Day):

Time (Hour, Minute, Second, Subsecond):

Time (Hour, Minute, Second, Subsecond):

Weekday:

ISO 8601 week-based year and week number:

The first week of YYYY starts with a Monday and includes YYYY-01-04. The days in the year before the first week are in the last week of the previous year.

Week number:

The first week of YYYY that starts with a Sunday or Monday (according to %U or %W). The days in the year before the first week are in week 0.

Seconds since the Epoch:

Literal string:

Combination:

$timestamp = Timestamp('2016-08-24T12:13:14')

# Notice the timestamp using a format that notices the ISO 8601 date format
notice($timestamp.strftime('%F')) # outputs '2016-08-24'

# Notice the timestamp using a format that notices weekday, month, day, time (as UTC), and year
notice($timestamp.strftime('%c')) # outputs 'Wed Aug 24 12:13:14 2016'

# Notice the timestamp using a specific timezone
notice($timestamp.strftime('%F %T %z', 'PST')) # outputs '2016-08-24 04:13:14 -0800'

# Notice the timestamp using timezone that is current for the evaluating process
notice($timestamp.strftime('%F %T', 'current')) # outputs the timestamp using the timezone for the current process

Format directives applicable to Timespan:

The format directive that represents the highest magnitude in the format will be allowed to overflow. I.e. if no “%D” is used but a “%H” is present, then the hours will be more than 23 in case the timespan reflects more than a day.

$duration = Timespan({ hours => 3, minutes => 20, seconds => 30 })

# Notice the duration using a format that outputs <hours>:<minutes>:<seconds>
notice($duration.strftime('%H:%M:%S')) # outputs '03:20:30'

# Notice the duration using a format that outputs <minutes>:<seconds>
notice($duration.strftime('%M:%S')) # outputs '200:30'

• Since 4.8.0

tag

• tag()
  • Return type(s): Any.

Add the specified tags to the containing class or definition. All contained objects will then acquire that tag, also.

tagged

• tagged()
  • Return type(s): Any.

A boolean function that tells you whether the current container is tagged with the specified tags. The tags are ANDed, so that all of the specified tags must be included for the function to return true.

template

• template()
  • Return type(s): Any.

Loads an ERB template from a module, evaluates it, and returns the resulting value as a string.

The argument to this function should be a <MODULE NAME>/<TEMPLATE FILE> reference, which will load <TEMPLATE FILE> from a module’s templates directory. (For example, the reference apache/vhost.conf.erb will load the file <MODULES DIRECTORY>/apache/templates/vhost.conf.erb.)

This function can also accept:

• An absolute path, which can load a template file from anywhere on disk.
• Multiple arguments, which will evaluate all of the specified templates and return their outputs concatenated into a single string.

then

• then(Any $arg, Callable[1,1] &$block)
  • Return type(s): Any.

Calls a lambda with the given argument unless the argument is undef. Returns undef if the argument is undef, and otherwise the result of giving the argument to the lambda.

This is useful to process a sequence of operations where an intermediate result may be undef (which makes the entire sequence undef). The then function is especially useful with the function dig which performs in a similar way “digging out” a value in a complex structure.

$data = {a => { b => [{x => 10, y => 20}, {x => 100, y => 200}]}}
notice $data.dig(a, b, 1, x).then |$x| { $x * 2 }

Would notice the value 200

Contrast this with:

$data = {a => { b => [{x => 10, y => 20}, {not_x => 100, why => 200}]}}
notice $data.dig(a, b, 1, x).then |$x| { $x * 2 }

Which would notice undef since the last lookup of ‘x’ results in undef which is returned (without calling the lambda given to the then function).

As a result there is no need for conditional logic or a temporary (non local) variable as the result is now either the wanted value (x) multiplied by 2 or undef.

Calls to then can be chained. In the next example, a structure is using an offset based on using 1 as the index to the first element (instead of 0 which is used in the language). We are not sure if user input actually contains an index at all, or if it is outside the range of available names.args.

# Names to choose from
$names = ['Ringo', 'Paul', 'George', 'John']

# Structure where 'beatle 2' is wanted (but where the number refers
# to 'Paul' because input comes from a source using 1 for the first
# element).

$data = ['singer', { beatle => 2 }]
$picked = assert_type(String,
  # the data we are interested in is the second in the array,
  # a hash, where we want the value of the key 'beatle'
  $data.dig(1, 'beatle')
    # and we want the index in $names before the given index
    .then |$x| { $names[$x-1] }
    # so we can construct a string with that beatle's name
    .then |$x| { "Picked Beatle '${x}'" }
)
notice $picked

Would notice “Picked Beatle ‘Paul’”, and would raise an error if the result was not a String.

• Since 4.5.0

tree_each

• tree_each(Variant[Iterator, Array, Hash, Object] $tree, Optional[OptionsType] $options, Callable[2,2] &$block)
  • Return type(s): Any.
• tree_each(Variant[Iterator, Array, Hash, Object] $tree, Optional[OptionsType] $options, Callable[1,1] &$block)
  • Return type(s): Any.
• tree_each(Variant[Iterator, Array, Hash, Object] $tree, Optional[OptionsType] $options)
  • Return type(s): Any.

Runs a lambda recursively and repeatedly using values from a data structure, then returns the unchanged data structure, or if a lambda is not given, returns an Iterator for the tree.

This function takes one mandatory argument, one optional, and an optional block in this order:

1. An Array, Hash, Iterator, or Object that the function will iterate over.
2. An optional hash with the options:
   • include_containers => Optional[Boolean] # default true - if containers should be given to the lambda
   • include_values => Optional[Boolean] # default true - if non containers should be given to the lambda
   • include_root => Optional[Boolean] # default true - if the root container should be given to the lambda
   • container_type => Optional[Type[Variant[Array, Hash, Object]]] # a type that determines what a container is - can only be set to a type that matches the default Variant[Array, Hash, Object].
   • order => Enum[depth_first, breadth_first] # default ´depth_first`, the order in which elements are visited
   • include_refs => Optional[Boolean] # default false, if attributes in objects marked as bing of reference kind should be included.
3. An optional lambda, which the function calls for each element in the first argument. It must accept one or two arguments; either $path, and $value, or just $value.

$data.tree_each |$path, $value| { <PUPPET CODE BLOCK> } $data.tree_each |$value| { <PUPPET CODE BLOCK> }

or

tree_each($data) |$path, $value| { <PUPPET CODE BLOCK> } tree_each($data) |$value| { <PUPPET CODE BLOCK> }

The parameter $path is always given as an Array containing the path that when applied to the tree as $data.dig(*$path) yields the $value. The $value` is the value at that path.

For Array values, the path will contain Integer entries with the array index, and for Hash values, the path will contain the hash key, which may be Any value. For Object containers, the entry is the name of the attribute (a String).

The tree is walked in either depth-first order, or in breadth-first order under the control of the order option, yielding each Array, Hash, Object, and each entry/attribute. The default is depth_first which means that children are processed before siblings. An order of breadth_first means that siblings are processed before children.

[1, [2, 3], 4]

Results in:

If containers are skipped:

• depth_first order 1, 2, 3, 4
• breadth_first order 1, 4,2, 3

If containers and root, are included:

• depth_first order [1, [2, 3], 4], 1, [2, 3], 2, 3, 4
• breadth_first order [1, [2, 3], 4], 1, [2, 3], 4, 2, 3

Typical use of the tree_each function include:

• a more efficient way to iterate over a tree than first using flatten on an array as that requires a new (potentially very large) array to be created
• when a tree needs to be transformed and ‘pretty printed’ in a template
• avoiding having to write a special recursive function when tree contains hashes (flatten does not work on hashes)

$data = [1, 2, [3, [4, 5]]]
$data.tree_each({include_containers => false}) |$v| { notice "$v" }

This would call the lambda 5 times with with the following values in sequence: 1, 2, 3, 4, 5

$data = [1, 2, [3, [4, 5]]]
$data.tree_each |$v| { notice "$v" }

This would call the lambda 7 times with the following values in sequence: 1, 2, [3, [4, 5]], 3, [4, 5], 4, 5

$data = [1, 2, [3, [4, 5]]]
$data.tree_each({include_values => false, include_root => false}) |$v| { notice "$v" }

This would call the lambda 2 times with the following values in sequence: [3, [4, 5]], [4, 5]

Any Puppet Type system data type can be used to filter what is considered to be a container, but it must be a narrower type than one of the default Array, Hash, Object types - for example it is not possible to make a String be a container type.

$data = [1, {a => 'hello', b => [100, 200]}, [3, [4, 5]]]
$data.tree_each({container_type => Array, include_containers => false} |$v| { notice "$v" }

Would call the lambda 5 times with 1, {a => 'hello', b => [100, 200]}, 3, 4, 5

Chaining When calling tree_each without a lambda the function produces an Iterator that can be chained into another iteration. Thus it is easy to use one of:

• reverse_each - get “leaves before root”
• filter - prune the tree
• map - transform each element
• reduce - produce something else

Note than when chaining, the value passed on is a Tuple with [path, value].

# A tree of some complexity (here very simple for readability)
$tree = [
 { name => 'user1', status => 'inactive', id => '10'},
 { name => 'user2', status => 'active', id => '20'}
]
notice $tree.tree_each.filter |$v| {
 $value = $v[1]
 $value =~ Hash and $value[status] == active
}

Would notice [[[1], {name => user2, status => active, id => 20}]], which can then be processed further as each filtered result appears as a Tuple with [path, value].

For general examples that demonstrates iteration see the Puppet iteration documentation.

type

• type(Any $value, Optional[Enum[detailed]] $inference_method)
  • Return type(s): Any.
• type(Any $value, Enum[reduced] $inference_method)
  • Return type(s): Any.
• type(Any $value, Enum[generalized] $inference_method)
  • Return type(s): Any.

Returns the data type of a given value with a given degree of generality.

type InferenceFidelity = Enum[generalized, reduced, detailed]

function type(Any $value, InferenceFidelity $fidelity = 'detailed') # returns Type

notice type(42) =~ Type[Integer]

Would notice true.

By default, the best possible inference is made where all details are retained. This is good when the type is used for further type calculations but is overwhelmingly rich in information if it is used in a error message.

The optional argument $fidelity may be given as (from lowest to highest fidelity):

• generalized - reduces to common type and drops size constraints
• reduced - reduces to common type in collections
• detailed - (default) all details about inferred types is retained

notice type([3.14, 42], 'generalized')
notice type([3.14, 42], 'reduced'')
notice type([3.14, 42], 'detailed')
notice type([3.14, 42])

Would notice the four values:

1. ‘Array[Numeric]’
2. ‘Array[Numeric, 2, 2]’
3. ‘Tuple[Float[3.14], Integer[42,42]]]’
4. ‘Tuple[Float[3.14], Integer[42,42]]]’

unique

• unique(String $string, Optional[Callable[String]] &$block)
  • Return type(s): Any.
• unique(Hash $hash, Optional[Callable[Any]] &$block)
  • Return type(s): Any.
• unique(Array $array, Optional[Callable[Any]] &$block)
  • Return type(s): Any.
• unique(Iterable $iterable, Optional[Callable[Any]] &$block)
  • Return type(s): Any.

Produces a unique set of values from an Iterable argument.

• If the argument is a String, the unique set of characters are returned as a new String.
• If the argument is a Hash, the resulting hash associates a set of keys with a set of unique values.
• For all other types of Iterable (Array, Iterator) the result is an Array with a unique set of entries.
• Comparison of all String values are case sensitive.
• An optional code block can be given - if present it is given each candidate value and its return is used instead of the given value. This enables transformation of the value before comparison. The result of the lambda is only used for comparison.
• The optional code block when used with a hash is given each value (not the keys).

# will produce 'abc'
"abcaabb".unique

# will produce ['a', 'b', 'c']
['a', 'b', 'c', 'a', 'a', 'b'].unique

# will produce { ['a', 'b'] => [10], ['c'] => [20]}
{'a' => 10, 'b' => 10, 'c' => 20}.unique

# will produce { 'a' => 10, 'c' => 20 } (use first key with first value)
Hash.new({'a' => 10, 'b' => 10, 'c' => 20}.unique.map |$k, $v| { [ $k[0] , $v[0]] })

# will produce { 'b' => 10, 'c' => 20 } (use last key with first value)
Hash.new({'a' => 10, 'b' => 10, 'c' => 20}.unique.map |$k, $v| { [ $k[-1] , $v[0]] })

# will produce [3, 2, 1]
[1,2,2,3,3].reverse_each.unique

# will produce [['sam', 'smith'], ['sue', 'smith']]
[['sam', 'smith'], ['sam', 'brown'], ['sue', 'smith']].unique |$x| { $x[0] }

# will produce [['sam', 'smith'], ['sam', 'brown']]
[['sam', 'smith'], ['sam', 'brown'], ['sue', 'smith']].unique |$x| { $x[1] }

# will produce ['aBc', 'bbb'] (using a lambda to make comparison using downcased (%d) strings)
['aBc', 'AbC', 'bbb'].unique |$x| { String($x,'%d') }

# will produce {[a] => [10], [b, c, d, e] => [11, 12, 100]}
{a => 10, b => 11, c => 12, d => 100, e => 11}.unique |$v| { if $v > 10 { big } else { $v } } 

Note that for Hash the result is slightly different than for the other data types. For those the result contains the first-found unique value, but for Hash it contains associations from a set of keys to the set of values clustered by the equality lambda (or the default value equality if no lambda was given). This makes the unique function more versatile for hashes in general, while requiring that the simple computation of “hash’s unique set of values” is performed as $hsh.map |$k, $v| { $v }.unique. (A unique set of hash keys is in general meaningless (since they are unique by definition) - although if processed with a different lambda for equality that would be different. First map the hash to an array of its keys if such a unique computation is wanted). If the more advanced clustering is wanted for one of the other data types, simply transform it into a Hash as shown in the following example.

# Array ['a', 'b', 'c'] to Hash with index results in
# {0 => 'a', 1 => 'b', 2 => 'c'}
Hash(['a', 'b', 'c'].map |$i, $v| { [$i, $v]})

# String "abc" to Hash with index results in
# {0 => 'a', 1 => 'b', 2 => 'c'}
Hash(Array("abc").map |$i,$v| { [$i, $v]})
"abc".to(Array).map |$i,$v| { [$i, $v]}.to(Hash)

unwrap

• unwrap(Sensitive $arg, Optional[Callable] &$block)
  • Return type(s): Any.

Unwraps a Sensitive value and returns the wrapped object.

$plaintext = 'hunter2'
$pw = Sensitive.new($plaintext)
notice("Wrapped object is $pw") #=> Prints "Wrapped object is Sensitive [value redacted]"
$unwrapped = $pw.unwrap
notice("Unwrapped object is $unwrapped") #=> Prints "Unwrapped object is hunter2"

You can optionally pass a block to unwrap in order to limit the scope where the unwrapped value is visible.

$pw = Sensitive.new('hunter2')
notice("Wrapped object is $pw") #=> Prints "Wrapped object is Sensitive [value redacted]"
$pw.unwrap |$unwrapped| {
  $conf = inline_template("password: ${unwrapped}\n")
  Sensitive.new($conf)
} #=> Returns a new Sensitive object containing an interpolated config file
# $unwrapped is now out of scope

values

• values(Hash $hsh)
  • Return type(s): Any.

Returns the values of a hash as an Array

$hsh = {"apples" => 3, "oranges" => 4 }
$hsh.values()
values($hsh)
# both results in the array [3, 4]

• Note that a hash in the puppet language accepts any data value (including undef) unless it is constrained with a Hash data type that narrows the allowed data types.
• For an empty hash, an empty array is returned.
• The order of the values is the same as the order in the hash (typically the order in which they were added).

versioncmp

• versioncmp(String $a, String $b)
  • Return type(s): Any.

Compares two version numbers.

Prototype:

\$result = versioncmp(a, b)

Where a and b are arbitrary version strings.

This function returns:

• 1 if version a is greater than version b
• 0 if the versions are equal
• -1 if version a is less than version b

This function uses the same version comparison algorithm used by Puppet’s package type.

warning

• warning(Any *$values)
  • *values — The values to log.
  • Return type(s): Undef.

Logs a message on the server at level notice.

with

• with(Any *$arg, Callable &$block)
  • Return type(s): Any.

Calls a lambda with the given arguments and returns the result.

Since a lambda’s scope is local to the lambda, you can use the with function to create private blocks of code within a class using variables whose values cannot be accessed outside of the lambda.

# Concatenate three strings into a single string formatted as a list.
$fruit = with("apples", "oranges", "bananas") |$x, $y, $z| {
  "${x}, ${y}, and ${z}"
}
$check_var = $x
# $fruit contains "apples, oranges, and bananas"
# $check_var is undefined, as the value of $x is local to the lambda.

yaml_data

• yaml_data(Struct[{path=>String[1]}] $options, Puppet::LookupContext $context)
  • Return type(s): Any.

NOTE: This page was generated from the Puppet source code on 2018-08-28 06:48:02 -0700