📅 最后修改于: 2021-01-08 05:01:29 🧑 作者: Mango
众所周知，Puppet使用Ruby编程语言，并且像其他编程语言一样，Ruby也支持函数。我们可以用Ruby语言编写函数，并且可以将其分布在人偶模块中。puppet 提供两种不同类型的功能：
语句：此类函数不返回任何值，而是用于执行独立任务的。它可用于在新清单文件中导入Puppet模块。
rvalue：在Puppet中，如果要使用返回类型定义函数，则可以使用rvalue函数。仅在语句需要值(例如case语句或赋值)时才可以使用rvalue。一个函数只能接受两个参数作为参数。
在Puppet中，我们可以根据需要创建功能。甚至Puppet也提供了许多内置功能。让我们看一些内置函数的列表：
| Function | Description | Syntax | Type |
|---|---|---|---|
| abs | It will return the absolute value of a Numeric value. | abs(Numeric($str_val)) | rvalue |
| alert | This function is used for logging a message on the server at level alert. | alert(Any *$values) | statement |
| break | Breaks an innermost iteration as if an end of input was found. This function doesn’t accept any argument. | break() | statement |
| binary_file | This function loads a binary file from a module or file system and returns binary content. | binary_file(String $path) | rvalue |
| call | Used to call an arbitrary function by name. | call(String $function_name, Any *$arguments, Optional[Callable] &$block) | statement |
| create_resources | This function is used to change a hash into a collection of resources and inserts them into the catalog. | create_resources($type, $resources) | statement |
| debug | Logs a message on the server at level debug. | debug(Any *$values) | statement |
| crit | Logs a message on the server at the level crit. | crit(Any *$values) | statement |
| defined | Verify whether a given class or resource type is defined. | defined(Variant[String, Type[CatalogEntry], Type[Type[CatalogEntry]]] *$vals) | rvalue |
| emerg | This function is used for logging a message on the server at level emerg. | emerg(Any *$values) | statement |
| fail | Fail with a parser error. | fail() | statement |
| err | This function is used for logging a message on the server at level err. | err(Any *$values) | statement |
| file | It takes a file from a module and returns its contents as a string. | file() | rvalue |
| fqdn_rand | Used to generate random numbers based on the fqdn of the node. | fqdn_rand(MAX, [SEED]) | rvalue |
| include | This is used to evaluate one or more classes. | include(Any *$names) | statement |
| info | This function is used for logging a message on the server at level info. | info(Any *$values) | statement |
| inline_template | This is used to evaluate a template string and return its value. | inline_template() | rvalue |
| join | This function is used to join an array of values into a string with elements separated by a delimiter. | join(Array $arg, Optional[String] $delimiter) | rvalue |
| keys | This function is used to return the keys of a hash as an Array. | keys(Hash $hsh) | rvalue |
| md5 | This function is used to return an MD5 hash value from a given string. | md5() | rvalue |
| new | This function creates a new instance of an object of a specified data type. | new(Type $type, Any *$args, Optional[Callable] &$block) | statement |
| notice | This function is used for logging a message on the server at level notice. | notice(Any *$values) | statement |
| realize | This is used to make a virtual object real. | realize() | statement |
| require | This is used to evaluate one or more classes and adding the required class as a dependency. | require(Any *$names) | statement |
| round | This is used to return an Integer value rounded to the nearest value. | round(Numeric $val) | rvalue |
| rstrip | Strips trailing spaces from a String | rstrip(String $arg) | rvalue |
| sha1 | This is used to return a SHA1 hash value from a given string. | sha1() | rvalue |
| sha256 | This function is used to Return a SHA256 hash value from a given string. | sha256() | rvalue |
| shellquote | This function is used to quote and concatenate arguments for use in Bourne shell. | shellquote() | rvalue |
| size | Used to return the size of String, Hash, Array, or Binary value. | size(Variant[Collection, String, Binary] $arg) | rvalue |
| length | Used to return the length of String, Hash, Array, or Binary value. | length(Variant[Collection, String, Binary] $arg) | rvalue |
| split | Splits a string into an array using a given pattern. | split(String $str, String $pattern) | rvalue |
| sprintf | This function does printf-style formatting of text. | sprintf() | rvalue |
| strip | Strips leading and trailing spaces from a String | strip(Iterable[Variant[String, Numeric]] $arg) | rvalue |
| tag | This function is used to add the given tags to the containing class or to the definition. | tag() | statement |
| tagged | This function is used to test whether the latest container is tagged with the given tags or not. It will return the Boolean value. | tagged() | rvalue |
| template | This function first loads an ERB template from the module and then evaluates the output value as a string. | template() | rvalue |
| upcase | This function is used to convert a String, Array, or Hash (recursively) into the upper case. | upcase(String $arg) | rvalue |
| values | This function is used to return the values of a hash as an Array. | values(Hash $hsh) | rvalue |
| versioncmp | This function is used to compare two version numbers. | versioncmp(String $a, String $b) | rvalue |
| warning | This function is used for logging a message on the server at the warning level. | warning(Any *$values) | statement |