The Puppet modules work as components of host configuration definitions. The myservice class installs packages, ensures the others assign them with resource-like behavior. Must use one space between the resource type and opening brace, one space between the Puppet automates the delivery and operation of the software that powers some of the biggest brands in the world. For example, 5 =~ Integer and 5 =~ Integer[1,10] both resolve to true. resources of that defined type anywhere in your manifests. way that is consistent with the Puppet style. This An opening square bracket [ using the new declaration's values for the parameters. Soft dependencies should be called out in the README.md, and must not be enforced as a documentation. For example, if the data type is [String], but the value must specifically be a path. Must include trailing commas after all resource attributes and parameter left operand is a value of that data type. Classes can also contain other classes, but you must manually specify that a class should be contained. The parent type of all types that are included in a Puppet result in compilation failures with a "duplicate resource declaration" error. always easy to detect. This consistency in code and module structure makes it easier to update and maintain the code. resource default. that includes classes from every level of the hierarchy. lines: Rather than just saying that there was a type mismatch for, Good: Parameter defaults set in the class with references to. encounter them in the code. Something that can be called (such as a function or lambda). Please file a JIRA ticket in our. your site manifest. If you are using an array of titles you must The matcher only accepts fully qualified class names without any leading colons. Multiple resources declared in a single block should be used only when there is also a This form is sent to the Puppet docs team. The equals sign should be aligned. Next lines, if applicable: Should declare local variables and perform variable defined resource type by writing a define Smart Class parameters You can override parameters of a Puppet module using Smart Class parameters if the module supports the use of parameters. your classes. Puppet is automatically aware of classes in modules and can autoload them by name. Puppet Code by Example: Part 2 - Medium JSON string representing an encoded JSON object for the Puppet classes Add the following custom fields to the cmdb_ci table in your ServiceNow instance: Note: Here, Puppet Classes is a JSON encoding of a Hash [String, Hash [String, Any]] type (informally, a Hash [ClassName, Parameters] object). Parameters to classes or defined types must be uniformly indented in two spaces from the the nested block by two spaces, and place each attribute on a separate line. The left section contains a list of possible parameters the class supports. Classes are top-scope variables (such as $::operatingsystem). An upper-case word matching one of the known data types. these variables are set based on user input when the class is declared, rather than with module was built to be used on. fail when no value matches. It takes one mandatory parameter. matter how many times you add the class, it is added to the catalog only once. The following code outputs 'hello world' via the Foo['bar'] defined type: When a class is declared, Puppet will try the following for each of its parameters: Use the override value from the declaration, if present. Each parameter can be preceeded by an optional data type. default_hierarchy to hierarchy. @param service_ensure the wanted state of services. should contain nothing other than the class or resource type definition. Particularly useful with kafo, as its default behaviour is to throw an error when a parameter is undocumented. Resource-like declarations look like normal resource declarations, using the special class pseudo-resource type. Defined resource types Class['ntp']. namespaces. Use semicolon-separated multiple resource bodies only in conjunction with a local default contain other classes, but you must use the contain function to explicitly specify when a class is contained. used. As long as your The hiera_include function uses include-like behavior. For example, if mode is present in the hash, you cant You can use these special values to attributes, one space after the longest resource key, arranging hashes for maximum metaparameters, merge the values from the container and any specific values from the see the Containing Classes section of the Containment page. The contain function uses include-like behavior. Includes may Managing Configurations Using Puppet Integration in Red Hat Satellite See module fundamentals to learn more about module structure and Resource-like declarations Required If you leave us your email, we may contact you regarding your feedback. . For both single- and double-quoted strings, escape the backslash to remove this special the elements on separate lines. require relationship with ntp will be applied after as parameters so tags can be used to selectively collect by environment or custom fact. it appears, such as when it is very short. Data types are useful in parameter lists, match (=~) expressions, case statements, and Comments No style guide can cover every circumstance you might run into when would be Apache::Vhost['homepages']. To send us feedback or let us know about a docs error, open a ticket (you need a Jira account) or leave a comment. should contain the following information, arranged in this order: Multiline descriptions must be uniformly indented by at least one visit our, Please enter your feedback and contact email, Open source Puppet vs Puppet Enterprise (PE), environment.conf: Per-environment settings, fileserver.conf: Custom fileserver mount points, autosign.conf: Basic certificate autosigning, csr_attributes.yaml: Certificate extensions, custom_trusted_oid_mapping.yaml: Short names for cert extension OIDs, Upgrade agents using the puppet_agent module, Infrastructure certificate revocation list (CRL), CSR attributes and certificate extensions, Regenerating certificates in a Puppet deployment, Designing system configs (roles and profiles), Develop types and providers with the Resource API, Low-level method for developing types and providers, Writing custom functions in the Puppet language, Using special features in implementation methods, Write a deferred function to store secrets, Installing and managing modules from the command line, Delete a module release from the Forge API, creating a custom data type Request a value from the external data source, using the key <class name>::<parameter name>. In addition to class-specific parameters, you can also specify a value for any metaparameter. Select the ntp Puppet class to change its configuration. It can accept: The hiera_include function requests a list of class names from Hiera, then declares all of them. at least one must be given, or an error of unsupported OS is raised. To set class parameter defaults with Hiera data in your The include, require, contain, and hiera_include functions let you safely declare a class multiple times; no matter how many times you declare it, a class will only be added to the catalog once. For example, a reference to the apache::vhost resource For example, use an Enum for input validation, instead of using a String and checking the contents of the string in the code. We ask for your email as we might contact you regarding your feedback. Choices: "string" "boolean" "integer" "real" "array" "hash" "yaml" "json" "none" To satisfy cross-module dependencies in a more portable way, include statements opening brace and the title, and no spaces between the title and For For more information on if/else statements, see Conditional Note that treating a parameter like a namevar and defaulting it to $title or $name does not make it a required A Puppet module is a collection of classes, manifests, resources, files, and templates. Note also that you can use resource collectors to override resource attributes in unrelated classes, although this feature should be handled with care. If you use inheritance for maintaining older modules, do not use it across module May align hash rockets (=>) within blocks of For an example, see the rabbitmq module. You can provide a value for any class parameter by specifying it as resource attribute; any parameters not specified will follow the normal external/default/fail lookup path. Smart Class parameters You can override parameters of a Puppet module using Smart Class parameters if the module supports the use of parameters. Include-like declarations are the most common; they are flexible and The Puppet modules work as components of host configuration definitions. doesn't add any resources to the catalog to do that, you must declare the class or assign it An increase in 'y' indicates minor changes: the non-breaking addition of new This includes READMEs help users of your module get the The default value, if any, for that element. parameters are parameters that are not set to anything, including undef. The right section contains the configuration options for the parameter selected. A contained class is automatically tagged with the name of its container. You can remove an attributes previous value without setting a new one by overriding it with the special value undef: This causes the attribute to be unmanaged by Puppet. class - Puppet: Passing parameters through classes - Stack Overflow puppet-lint-param-docs.gemspec README.md puppet-lint parameter documentation check Adds a new puppet-lint check to verify all class and defined type parameters have been documented. This pattern works by guaranteeing that the params class is evaluated before Puppet attempts to evaluate the main classs parameter list. We ask for your email as we might contact you regarding your feedback. by writing a class definition in a manifest (.pp) file. If you are maintaining older modules, you might encounter cases where class parameter This }. Separating into public and private classes or defined types required in a specific set of use cases. Language: Data types: Hashes rspec-puppet does not do the class name parsing and lookup that the Puppet parser would do for you. The $title and $name variables are both set to the resource. Resource references identify a specific Puppet resource by its type and title. defined type's name automatically, so they cannot be used as parameters. Puppet by Perforce gives IT operations teams back their time and offers peace of mind with infrastructure automation that enables security and compliance. A class definition statement isnt an expression and cant be used where a value is expected. defaults. For more information on how Puppet uses your personal information, see Structure classes and defined types to accomplish one task. any parameters and fail catalog compilation if any parameters are invalid. whether two data types are equal, whether one is a subset of another, and so on. (Multiple declarations OK; relies on external data for parameters.) external data for parameters. Each value in the Puppet For example, type(3) returns Integer[3,3]. something is a string with the expression $possible_string =~ String, or specify that a class writing documentation comments. you might encounter the use of a params.pp pattern. write, the $facts hash is clearer, easier to because not all users have implemented Hiera. A parent type of all data types except the non serializeable types. automatically tagged with the name of its container. For details, see the Containing Classes section of the Containment page. manifest, and give the manifest file the same name as the defined type. Use Hiera data in your module to set parameter Exported resources should be opt-in rather than opt-out. value for any of those attributes. Your module must be versioned, and have metadata defined in the metadata.json file. This means: Declare symbolic links with an ensure value of ensure => link. structures to make it easier to update and maintain. Docs Open Source Puppet Syntax and settings The Puppet language Variables Variables Sections Assigning variables Resolution Interpolation Scope Unassigned variables and strict mode Naming variables Variable names Variables store values so that those values can be accessed in code later. Each new element line indented one level. Every . visit our, Please enter your feedback and contact email, Open source Puppet vs Puppet Enterprise (PE), environment.conf: Per-environment settings, fileserver.conf: Custom fileserver mount points, autosign.conf: Basic certificate autosigning, csr_attributes.yaml: Certificate extensions, custom_trusted_oid_mapping.yaml: Short names for cert extension OIDs, Upgrade agents using the puppet_agent module, Infrastructure certificate revocation list (CRL), CSR attributes and certificate extensions, Regenerating certificates in a Puppet deployment, Designing system configs (roles and profiles), Develop types and providers with the Resource API, Low-level method for developing types and providers, Writing custom functions in the Puppet language, Using special features in implementation methods, Write a deferred function to store secrets, Installing and managing modules from the command line, Delete a module release from the Forge API, Conditional By default, Type matches any value that Since the base classs local scope already exists before the new classs parameters get declared, those parameters can be set based on information in the base class. You have the option The variables $title and $name are both set to the class When a class is declared, Puppet will try the following for each of its parameters: Aside: Why do resource-like declarations have to be unique? Type your class parameters wherever possible, and be specific when using a type. Getting started with PE and the ServiceNow CMDB integration illegal value. First and last lines used only for the syntax of that data type. easier to use. The definition does not cause the code in the block to be added to the catalog; it only Parameters you create modules with Puppet Development Kit or the puppet module generate command, the generated README Consider the following scenario. Every resource contained in the resource declaration also has that metaparameter. There cant be any space between the Select a class from the list that has parameters as indicated in the Parameters column. Public The contain function is used inside another class definition to declare The built-in function Strings processes the README and comments from your code resources different across instances, include the value of $title or An enumeration of regular expression patterns. . This displays a new screen. Case statements must have default cases. Parameters without contributions easier. . customized by the user, while private classes should contain things you do not expect the An optional parameter list, which consists of: A comma-separated list of parameters, such as: An optional data type, which restricts the allowed values for the parameter. If not specified, the data type defaults to, A variable name to represent the parameter, including the When talking about resource declarations in Puppet, parameter is a synonym for attribute. have: Good: Array with multiple elements on multiple compilation. Each file in the manifest directory Instead, we recommend using parameters that Use backslash (\) as an escape character. As an example, to include These quoting requirements do not apply to expressions that evaluate to strings. privacy policy. To reduce If a resource declaration includes an ensure attribute, it should be the This avoids This single class name declaration declares the class only once and has no additional on) in your module. 2: Value type: Type: Data: What kinds of values can be used as values. Selectors should omit default selections only if you explicitly want catalog compilation to If you tried to set, Abstract data types let you write more sophisticated and flexible restrictions. If no data type is specified, values of any data type are permitted. If you need to read internal data from another class, you should generally use qualified variable names instead of assigning parent scopes. user to change via parameters. declaring them in init.pp, but has the benefit of Rather than the usual assignment statement, each instance of the defined type uses its It is especially useful when you want your default values to change based on system facts and other data, since it lets you isolate and encapsulate all that conditional logic. Strings uses YARD-style tags and comments, along with the structure of the . after the final value. except as listed below. For more information, see the Hiera documentation. formatting is consistent throughout the chain, it is up to your own judgment. meaning: \\ This means that for every backslash To increase readability of arrays and hashes, it is almost always beneficial to break up Keep the the manifest file the same name as the class. dollar sign (. and displayed by Puppet Strings, GitHub, and the Puppet Forge. Put the lines of code in the following order: Following lines, if applicable: Define parameters. Strings documentation for details on usage, installation, and correctly declare a resource of a defined type in the same way you would declare a resource of a become a dependency of the surrounding container. How you order parameters is personal preference. When you need to override resource attributes in the base class. If The match operators =~ and !~ accept a data type on the right operand, and test whether the built-in type. Classes, defined types, and lambdas all let you I'm pretty new to puppet, and I've got stuck on how to notify a class with a parameter. automatically loads any classes that are present in a valid module. You can use parameters to restrict which values Class matches, but it will matches no values. module overwrites everything in animportantfile.conf.). state of myservice, and creates a tempfile with given named blocks of Puppet code that are Since overridden values from the class declaration always win, are computed at compile-time, and do not have a built-in hierarchy for resolving conflicts, allowing repeated overrides would cause catalog compilation to be unreliable and evaluation-order dependent. # If any parameters have been set on Package[httpd] other than . The data type of literal data type values is Type. Major upgrade from Puppet 3.8.x, Using and extending Puppet Server, Server-specific Puppet API endpoints, Writing functions (modern Ruby API), Reports: Tracking Puppet's activity, Extensions for assigning classes to nodes, Misc. You cannot apply the noop metaparameter to resource-like class declarations. The Puppet README template offers a basic format you can use. quotes at all. If you specify a key type, a value type is mandatory. This style guide applies to Puppet 4 and later. Puppet Strings style guide This form is sent to the Puppet docs team. checks the resource parameter's value at runtime to make sure that it has the right data If a class parameter lacks a A variable name to represent the parameter, including the. requires another class or defined type, put graceful failures in place if those required The left section contains a list of possible parameters the class supports. arrows. If you leave us your email, we may contact you regarding your feedback. classes in node definitions, at top scope in the site manifest, and in other classes or Namevars and name. If you use a hash to set attributes for a resource, you cannot set a different, explicit complete rewrite. An optional trailing comma after the last parameter. classes or defined types should contain the parts of the module meant to be configured or See an issue? colon. A comma-separated list of values or expressions. theforeman.foreman.smart_class_parameter module - Ansible This can allow classes or defined types to manage their own dependencies, and lets you create overlapping role classes where a given node can have more than one role. The following data types are available in the Puppet language. Good naming of aliases can also serve as documentation, making your code easier Every resource in a class gets automatically tagged with the classs name and each of its namespace segments. deleted. one or more classes and contain those classes in the surrounding class. A parent type of all data directly representable as JSON. duplicate class declarations and vendor lock-in. Since it uses the array lookup type, it will get a combined list that includes classes from every level of the hierarchy. If readability becomes a problem, consider creating a custom data type You can declare a class with this behavior with one of four functions: parameters such as passwords or IP addresses might not have reasonable default values. Any additional information about valid values that is not clear from the data This is a known bug. Your hard dependency declarations should not be unbounded. also set, To use some attributes from a hash and override others, either use a hash to set The right section contains the configuration options for the parameter selected. hard requirement in your metadata.json. See Puppet Use the The general form of a resource reference is: The resource type, capitalized. parameters or conditional logic. Declare them as close to node scope as possible. facts for configuration, use a parameter for that data. A contained class is Within a manifest, resources should be grouped by logical relationship to each other, (This also causes a warning for the unrecognized escape.) Note that if a class parameter lacks a default value, the modules user must set a value themselves (either in their external data or an override). Validations should validate Like the Mytype-style data types, it matches no values that can be produced in the Puppet language. Metaparameters that can take more than one value, such as the An optional parameter list, which consists of: A comma-separated list of parameters, such as, An optional data type, which restricts the allowed values Change error), Handling file paths on Windows, Conditional statements and expressions, Reserved words and acceptable names, About values and data types, Embedded Puppet (EPP) template syntax, Embedded Ruby (ERB) template syntax, Namespaces and autoloading, Introduction to writing functions, Special features in implementation methods, Writing iterative functions, Writing functions (legacy Ruby API avoid), All resource types (single-page reference), Optional resource types for Windows, Exec tips and examples for Windows, File tips and examples for Windows, User and group tips and examples for Windows, Package tips and examples for Windows, Writing custom report processors, Puppet::Transaction::Report object format, Settings (configuration reference), Configuring external certificate authority, External SSL termination with Puppet Server, CSR attributes and certificate extensions, Regenerating all certificates in a Puppet deployment, set based on user input when the class is declared, see the Containing Classes section of the Containment page, use resource collectors to override resource attributes, adding attributes to an existing resource. Declaring a new resource of the defined type causes Puppet to re-evaluate the block of code in the definition, parameters take, and the order in which they must be given. In this example declaration, the . Requests a value from the external data source, using the key. A parameterized class enables other users of your code base to change the behavior and output of the class: At evaluation time, Puppet raises an error if A string SHOULD be enclosed in double quotes if it: Modules that adopt this string quoting style MUST enclose all strings in double quotes, Or is adding the parameter to the service class and including ONLY that enough, because the service class has dependencies, like this: . legible. For example, if a resource has a before relationship with the Hashes don't specify a data type in the definition statement, the parameter accepts values of any This design pattern can make for significantly cleaner code while enabling some really sophisticated behavior around default values. Resource types are mostly useful if you want to pass parameters to the class but can't or don't use Hiera. for example, code in Puppet modules or classes. resource-like. To use a number Resource-like class declarations to read, you can break it up on multiples lines to improve readability. your README with a complete list of all classes, types, providers, defined types, and except as listed below. classes in your module. because you cannot create local variables with The following data types are available in Puppet: Core data types These are the "real" data types, which make up the most common values you'll interact with in the Puppet language. They allow you to override class readability is crucial. This allows you to make special-case classes that extend the functionality of a more general base class. not use upper-case letters within a word, such as Using the type system | Puppet 4 Essentials - Second Edition Although plain top-scope variables are easier to Can be a simple object only having attributes, or a the $facts whitespace is allowed, but you cant have a trailing comma Any resource can specifically override metaparameter values Ensure the Override check box is selected. For details about updating existing params Chapter 6. Configuring Puppet Smart Class Parameters repetitive phrasing, we don't include the word 'Puppet' classes or defined types are not declared elsewhere. In such cases, every resource contained in the class will also have that metaparameter: Classes can also be assigned to nodes by external node classifiers and LDAP node data. This variables. Include a brief description, the valid options, A type that represents all types that allow iteration. classes: Defining a class makes it available for later use. two literal backslashes in the string, you would use four backslashes in total. Example [Visual Basic, C#] The following example creates a DB2 Parameter and displays the ParameterName . the referenced data files in the data directory. For example, the value String represents the data type of strings. See Defining classes for details about setting parameter your manifests or assigning them from an external node classifier