path: root/README.markdown

# Puppet Labs Standard Library #

[![Build Status](https://travis-ci.org/puppetlabs/puppetlabs-stdlib.png?branch=master)](https://travis-ci.org/puppetlabs/puppetlabs-stdlib)

This module provides a "standard library" of resources for developing Puppet
Modules.  This modules will include the following additions to Puppet

 * Stages
 * Facts
 * Functions
 * Defined resource types
 * Types
 * Providers

This module is officially curated and provided by Puppet Labs.  The modules
Puppet Labs writes and distributes will make heavy use of this standard
library.

To report or research a bug with any part of this module, please go to
[http://projects.puppetlabs.com/projects/stdlib](http://projects.puppetlabs.com/projects/stdlib)

# Versions #

This module follows semver.org (v1.0.0) versioning guidelines.  The standard
library module is released as part of [Puppet
Enterprise](http://puppetlabs.com/puppet/puppet-enterprise/) and as a result
older versions of Puppet Enterprise that Puppet Labs still supports will have
bugfix maintenance branches periodically "merged up" into master.  The current
list of integration branches are:

 * v2.1.x (v2.1.1 released in PE 1.2, 1.2.1, 1.2.3, 1.2.4)
 * v2.2.x (Never released as part of PE, only to the Forge)
 * v2.3.x (Released in PE 2.5.x)
 * master (mainline development branch)

The first Puppet Enterprise version including the stdlib module is Puppet
Enterprise 1.2.

# Compatibility #

The stdlib module does not work with Puppet versions released prior to Puppet
2.6.0.

## stdlib 2.x ##

All stdlib releases in the 2.0 major version support Puppet 2.6 and Puppet 2.7.

## stdlib 3.x ##

The 3.0 major release of stdlib drops support for Puppet 2.6.  Stdlib 3.x
supports Puppet 2 and Puppet 3.

# Functions #

abs
---
Returns the absolute value of a number, for example -34.56 becomes 34.56. Takes
a single integer and float value as an argument.


- *Type*: rvalue

bool2num
--------
Converts a boolean to a number. Converts the values:
false, f, 0, n, and no to 0
true, t, 1, y, and yes to 1
    Requires a single boolean or string as an input.


- *Type*: rvalue

capitalize
----------
Capitalizes the first letter of a string or array of strings.
Requires either a single string or an array as an input.


- *Type*: rvalue

chomp
-----
Removes the record separator from the end of a string or an array of strings,
for example `hello\n` becomes `hello`.  Requires a single string or array as an
input.


- *Type*: rvalue

chop
----
Returns a new string with the last character removed. If the string ends
with `\r\n`, both characters are removed. Applying chop to an empty
string returns an empty string. If you wish to merely remove record
separators then you should use the `chomp` function.
Requires a string or array of strings as input.


- *Type*: rvalue

concat
-----
Appends the contents of the second array onto the first array.


- *Type*: rvalue

defined_with_params
-------------------
Takes a resource reference and an optional hash of attributes.

Returns true if a resource with the specified attributes has already been added
to the catalog, and false otherwise.

    user { 'dan':
      ensure => present,
    }

    if ! defined_with_params(User[dan], {'ensure' => 'present' }) {
      user { 'dan': ensure => present, }
    }


- *Type*: rvalue

delete
------
Deletes a selected element from an array.

*Examples:*

    delete(['a','b','c'], 'b')

Would return: ['a','c']


- *Type*: rvalue

delete_at
---------
Deletes a determined indexed value from an array.

*Examples:*

    delete_at(['a','b','c'], 1)

Would return: ['a','c']


- *Type*: rvalue

downcase
--------
Converts the case of a string or all strings in an array to lower case.


- *Type*: rvalue

empty
-----
Returns true if the variable is empty.


- *Type*: rvalue

ensure_resource
---------------
Takes a resource type, title, and a list of attributes that describe a
resource.

    user { 'dan':
      ensure => present,
    }

This example only creates the resource if it does not already exist:

    ensure_resource('user, 'dan', {'ensure' => 'present' })

If the resource already exists but does not match the specified parameters,
this function will attempt to recreate the resource leading to a duplicate
resource definition error.



- *Type*: statement

flatten
-------
This function flattens any deeply nested arrays and returns a single flat array
as a result.

*Examples:*

    flatten(['a', ['b', ['c']]])

Would return: ['a','b','c']


- *Type*: rvalue

floor
-----
Returns the largest integer less or equal to the argument.
Takes a single numeric value as an argument.

*Examples:*

    floor('3.8')

Would return: '3'


- *Type*: rvalue

fqdn_rotate
-----------
Rotates an array a random number of times based on a nodes fqdn.


- *Type*: rvalue

get_module_path
---------------
Returns the absolute path of the specified module for the current
environment.

Example:
  $module_path = get_module_path('stdlib')


- *Type*: rvalue

getparam
--------

Takes a resource reference and name of the parameter and returns
value of resource's parameter.

For example:

    define example_resource($param) {
    }

    example_resource { "example_resource_instance":
        param => "param_value"
    }

    getparam(Example_resource["example_resource_instance"], "param")

- *Type*: rvalue

getvar
------
Lookup a variable in a remote namespace.

For example:

    $foo = getvar('site::data::foo')
    # Equivalent to $foo = $site::data::foo

This is useful if the namespace itself is stored in a string:

    $datalocation = 'site::data'
    $bar = getvar("${datalocation}::bar")
    # Equivalent to $bar = $site::data::bar


- *Type*: rvalue

grep
----
This function searches through an array and returns any elements that match
the provided regular expression.

*Examples:*

    grep(['aaa','bbb','ccc','aaaddd'], 'aaa')

Would return:

    ['aaa','aaaddd']


- *Type*: rvalue

has_key
-------
Determine if a hash has a certain key value.

Example:

    $my_hash = {'key_one' => 'value_one'}
    if has_key($my_hash, 'key_two') {
      notice('we will not reach here')
    }
    if has_key($my_hash, 'key_one') {
      notice('this will be printed')
    }



- *Type*: rvalue

hash
----
This function converts and array into a hash.

*Examples:*

    hash(['a',1,'b',2,'c',3])

Would return: {'a'=>1,'b'=>2,'c'=>3}


- *Type*: rvalue

is_array
--------
Returns true if the variable passed to this function is an array.


- *Type*: rvalue

is_domain_name
--------------
Returns true if the string passed to this function is a syntactically correct domain name.


- *Type*: rvalue

is_float
--------
Returns true if the variable passed to this function is a float.


- *Type*: rvalue

is_hash
-------
Returns true if the variable passed to this function is a hash.


- *Type*: rvalue

is_integer
----------
Returns true if the variable returned to this string is an integer.


- *Type*: rvalue

is_ip_address
-------------
Returns true if the string passed to this function is a valid IP address.


- *Type*: rvalue

is_mac_address
--------------
Returns true if the string passed to this function is a valid mac address.


- *Type*: rvalue

is_numeric
----------
Returns true if the variable passed to this function is a number.


- *Type*: rvalue

is_string
---------
Returns true if the variable passed to this function is a string.


- *Type*: rvalue

join
----
This function joins an array into a string using a seperator.

*Examples:*

    join(['a','b','c'], ",")

Would result in: "a,b,c"


- *Type*: rvalue

keys
----
Returns the keys of a hash as an array.


- *Type*: rvalue

loadyaml
--------
Load a YAML file containing an array, string, or hash, and return the data
in the corresponding native data type.

For example:

    $myhash = loadyaml('/etc/puppet/data/myhash.yaml')


- *Type*: rvalue

lstrip
------
Strips leading spaces to the left of a string.


- *Type*: rvalue

member
------
This function determines if a variable is a member of an array.

*Examples:*

    member(['a','b'], 'b')

Would return: true

    member(['a','b'], 'c')

Would return: false


- *Type*: rvalue

merge
-----
Merges two or more hashes together and returns the resulting hash.

For example:

    $hash1 = {'one' => 1, 'two', => 2}
    $hash2 = {'two' => 'dos', 'three', => 'tres'}
    $merged_hash = merge($hash1, $hash2)
    # The resulting hash is equivalent to:
    # $merged_hash =  {'one' => 1, 'two' => 'dos', 'three' => 'tres'}

When there is a duplicate key, the key in the rightmost hash will "win."



- *Type*: rvalue

num2bool
--------
This function converts a number into a true boolean. Zero becomes false. Numbers
higher then 0 become true.


- *Type*: rvalue

parsejson
---------
This function accepts JSON as a string and converts into the correct Puppet
structure.


- *Type*: rvalue

parseyaml
---------
This function accepts YAML as a string and converts it into the correct
Puppet structure.


- *Type*: rvalue

prefix
------
This function applies a prefix to all elements in an array.

*Examples:*

    prefix(['a','b','c'], 'p')

Will return: ['pa','pb','pc']


- *Type*: rvalue

range
-----
When given range in the form of (start, stop) it will extrapolate a range as
an array.

*Examples:*

    range("0", "9")

Will return: [0,1,2,3,4,5,6,7,8,9]

    range("00", "09")

Will return: [0,1,2,3,4,5,6,7,8,9] (Zero padded strings are converted to
integers automatically)

    range("a", "c")

Will return: ["a","b","c"]

    range("host01", "host10")

Will return: ["host01", "host02", ..., "host09", "host10"]


- *Type*: rvalue

reverse
-------
Reverses the order of a string or array.


- *Type*: rvalue

rstrip
------
Strips leading spaces to the right of the string.


- *Type*: rvalue

shuffle
-------
Randomizes the order of a string or array elements.


- *Type*: rvalue

size
----
Returns the number of elements in a string or array.


- *Type*: rvalue

sort
----
Sorts strings and arrays lexically.


- *Type*: rvalue

squeeze
-------
Returns a new string where runs of the same character that occur in this set
are replaced by a single character.


- *Type*: rvalue

str2bool
--------
This converts a string to a boolean. This attempt to convert strings that
contain things like: y, 1, t, true to 'true' and strings that contain things
like: 0, f, n, false, no to 'false'.


- *Type*: rvalue

str2saltedsha512
----------------
This converts a string to a salted-SHA512 password hash (which is used for OS X
versions >= 10.7). Given any simple string, you will get a hex version of a
salted-SHA512 password hash that can be inserted into your Puppet manifests as
a valid password attribute.


- *Type*: rvalue

strftime
--------
This function returns formatted time.

*Examples:*

To return the time since epoch:

    strftime("%s")

To return the date:

    strftime("%Y-%m-%d")

*Format meaning:*

    %a - The abbreviated weekday name (``Sun'')
    %A - The  full  weekday  name (``Sunday'')
    %b - The abbreviated month name (``Jan'')
    %B - The  full  month  name (``January'')
    %c - The preferred local date and time representation
    %C - Century (20 in 2009)
    %d - Day of the month (01..31)
    %D - Date (%m/%d/%y)
    %e - Day of the month, blank-padded ( 1..31)
    %F - Equivalent to %Y-%m-%d (the ISO 8601 date format)
    %h - Equivalent to %b
    %H - Hour of the day, 24-hour clock (00..23)
    %I - Hour of the day, 12-hour clock (01..12)
    %j - Day of the year (001..366)
    %k - hour, 24-hour clock, blank-padded ( 0..23)
    %l - hour, 12-hour clock, blank-padded ( 0..12)
    %L - Millisecond of the second (000..999)
    %m - Month of the year (01..12)
    %M - Minute of the hour (00..59)
    %n - Newline (
)
    %N - Fractional seconds digits, default is 9 digits (nanosecond)
            %3N  millisecond (3 digits)
            %6N  microsecond (6 digits)
            %9N  nanosecond (9 digits)
    %p - Meridian indicator (``AM''  or  ``PM'')
    %P - Meridian indicator (``am''  or  ``pm'')
    %r - time, 12-hour (same as %I:%M:%S %p)
    %R - time, 24-hour (%H:%M)
    %s - Number of seconds since 1970-01-01 00:00:00 UTC.
    %S - Second of the minute (00..60)
    %t - Tab character (	)
    %T - time, 24-hour (%H:%M:%S)
    %u - Day of the week as a decimal, Monday being 1. (1..7)
    %U - Week  number  of the current year,
            starting with the first Sunday as the first
            day of the first week (00..53)
    %v - VMS date (%e-%b-%Y)
    %V - Week number of year according to ISO 8601 (01..53)
    %W - Week  number  of the current year,
            starting with the first Monday as the first
            day of the first week (00..53)
    %w - Day of the week (Sunday is 0, 0..6)
    %x - Preferred representation for the date alone, no time
    %X - Preferred representation for the time alone, no date
    %y - Year without a century (00..99)
    %Y - Year with century
    %z - Time zone as  hour offset from UTC (e.g. +0900)
    %Z - Time zone name
    %% - Literal ``%'' character


- *Type*: rvalue

strip
-----
This function removes leading and trailing whitespace from a string or from
every string inside an array.

*Examples:*

    strip("    aaa   ")

Would result in: "aaa"


- *Type*: rvalue

suffix
------
This function applies a suffix to all elements in an array.

*Examples:*

    suffix(['a','b','c'], 'p')

Will return: ['ap','bp','cp']


- *Type*: rvalue

swapcase
--------
This function will swap the existing case of a string.

*Examples:*

    swapcase("aBcD")

Would result in: "AbCd"


- *Type*: rvalue

time
----
This function will return the current time since epoch as an integer.

*Examples:*

    time()

Will return something like: 1311972653


- *Type*: rvalue

to_bytes
--------
Converts the argument into bytes, for example 4 kB becomes 4096.
Takes a single string value as an argument.


- *Type*: rvalue

type
----
Returns the type when passed a variable. Type can be one of:

* string
* array
* hash
* float
* integer
* boolean


- *Type*: rvalue

unique
------
This function will remove duplicates from strings and arrays.

*Examples:*

    unique("aabbcc")

Will return:

    abc

You can also use this with arrays:

    unique(["a","a","b","b","c","c"])

This returns:

    ["a","b","c"]


- *Type*: rvalue

upcase
------
Converts a string or an array of strings to uppercase.

*Examples:*

    upcase("abcd")

Will return:

    ABCD


- *Type*: rvalue

validate_absolute_path
----------------------
Validate the string represents an absolute path in the filesystem.  This function works
for windows and unix style paths.

The following values will pass:

    $my_path = "C:/Program Files (x86)/Puppet Labs/Puppet"
    validate_absolute_path($my_path)
    $my_path2 = "/var/lib/puppet"
    validate_absolute_path($my_path2)


The following values will fail, causing compilation to abort:

    validate_absolute_path(true)
    validate_absolute_path([ 'var/lib/puppet', '/var/foo' ])
    validate_absolute_path([ '/var/lib/puppet', 'var/foo' ])
    $undefined = undef
    validate_absolute_path($undefined)



- *Type*: statement

validate_array
--------------
Validate that all passed values are array data structures. Abort catalog
compilation if any value fails this check.

The following values will pass:

    $my_array = [ 'one', 'two' ]
    validate_array($my_array)

The following values will fail, causing compilation to abort:

    validate_array(true)
    validate_array('some_string')
    $undefined = undef
    validate_array($undefined)



- *Type*: statement

validate_augeas
--------------
Perform validation of a string using an Augeas lens
The first argument of this function should be a string to
test, and the second argument should be the name of the Augeas lens to use.
If Augeas fails to parse the string with the lens, the compilation will
abort with a parse error.

A third argument can be specified, listing paths which should
not be found in the file. The `$file` variable points to the location
of the temporary file being tested in the Augeas tree.

For example, if you want to make sure your passwd content never contains
a user `foo`, you could write:

    validate_augeas($passwdcontent, 'Passwd.lns', ['$file/foo'])

Or if you wanted to ensure that no users used the '/bin/barsh' shell,
you could use:

    validate_augeas($passwdcontent, 'Passwd.lns', ['$file/*[shell="/bin/barsh"]']

If a fourth argument is specified, this will be the error message raised and
seen by the user.

A helpful error message can be returned like this:

    validate_augeas($sudoerscontent, 'Sudoers.lns', [], 'Failed to validate sudoers content with Augeas')


- *Type*: statement

validate_bool
-------------
Validate that all passed values are either true or false. Abort catalog
compilation if any value fails this check.

The following values will pass:

    $iamtrue = true
    validate_bool(true)
    validate_bool(true, true, false, $iamtrue)

The following values will fail, causing compilation to abort:

    $some_array = [ true ]
    validate_bool("false")
    validate_bool("true")
    validate_bool($some_array)



- *Type*: statement


validate_cmd
-------------
Perform validation of a string with an external command.
The first argument of this function should be a string to
test, and the second argument should be a path to a test command
taking a file as last argument. If the command, launched against
a tempfile containing the passed string, returns a non-null value,
compilation will abort with a parse error.

If a third argument is specified, this will be the error message raised and
seen by the user.

A helpful error message can be returned like this:

Example:

    validate_cmd($sudoerscontent, '/usr/sbin/visudo -c -f', 'Visudo failed to validate sudoers content')



- *Type*: statement

validate_hash
-------------
Validate that all passed values are hash data structures. Abort catalog
compilation if any value fails this check.

The following values will pass:

    $my_hash = { 'one' => 'two' }
    validate_hash($my_hash)

The following values will fail, causing compilation to abort:

    validate_hash(true)
    validate_hash('some_string')
    $undefined = undef
    validate_hash($undefined)



- *Type*: statement

validate_re
-----------
Perform simple validation of a string against one or more regular
expressions. The first argument of this function should be a string to
test, and the second argument should be a stringified regular expression
(without the // delimiters) or an array of regular expressions.  If none
of the regular expressions match the string passed in, compilation will
abort with a parse error.

If a third argument is specified, this will be the error message raised and
seen by the user.

The following strings will validate against the regular expressions:

    validate_re('one', '^one$')
    validate_re('one', [ '^one', '^two' ])

The following strings will fail to validate, causing compilation to abort:

    validate_re('one', [ '^two', '^three' ])

A helpful error message can be returned like this:

    validate_re($::puppetversion, '^2.7', 'The $puppetversion fact value does not match 2.7')



- *Type*: statement

validate_slength
----------------
Validate that the first argument is a string (or an array of strings), and
less/equal to than the length of the second argument.  It fails if the first
argument is not a string or array of strings, and if arg 2 is not convertable
to a number.

The following values will pass:

  validate_slength("discombobulate",17)
  validate_slength(["discombobulate","moo"],17)

The following valueis will not:

  validate_slength("discombobulate",1)
  validate_slength(["discombobulate","thermometer"],5)



- *Type*: statement

validate_string
---------------
Validate that all passed values are string data structures. Abort catalog
compilation if any value fails this check.

The following values will pass:

    $my_string = "one two"
    validate_string($my_string, 'three')

The following values will fail, causing compilation to abort:

    validate_string(true)
    validate_string([ 'some', 'array' ])
    $undefined = undef
    validate_string($undefined)



- *Type*: statement

values
------
When given a hash this function will return the values of that hash.

*Examples:*

    $hash = {
      'a' => 1,
      'b' => 2,
      'c' => 3,
    }
    values($hash)

This example would return:

    [1,2,3]


- *Type*: rvalue

values_at
---------
Finds value inside an array based on location.

The first argument is the array you want to analyze, and the second element can
be a combination of:

* A single numeric index
* A range in the form of 'start-stop' (eg. 4-9)
* An array combining the above

*Examples*:

    values_at(['a','b','c'], 2)

Would return ['c'].

    values_at(['a','b','c'], ["0-1"])

Would return ['a','b'].

    values_at(['a','b','c','d','e'], [0, "2-3"])

Would return ['a','c','d'].


- *Type*: rvalue

zip
---
Takes one element from first array and merges corresponding elements from second array. This generates a sequence of n-element arrays, where n is one more than the count of arguments.

*Example:*

    zip(['1','2','3'],['4','5','6'])

Would result in:

    ["1", "4"], ["2", "5"], ["3", "6"]


- *Type*: rvalue