Case statements must have default cases. Each namespace segment must be capitalized when writing a resource reference, collector, or A Puppet module is a collection of classes, manifests, resources, files, and templates. highlighting the structure of the module and making the function and structure more clarity and improved readability. The hiera_include function uses include-like behavior. The values of these variables are not set with normal assignment statements or looked up from top or node scope; instead, they are set based on user input when the class is declared. The following data types are available in the Puppet language. built-in type. "new". The equals sign should be aligned. 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. not merged into overriding values. defaults are required parameters, and you must specify a value for them when you declare the privacy policy. Note that treating a parameter like a namevar and defaulting it to $title or $name does not make it a required See the topic about creating reference documentation for details. organization guidelines. Similarly, any resource that forms a Separating classes and defined types into separate files is functionally identical to syntactically valid. This See an issue? Use the override value from the declaration, if present. privacy policy. The following code outputs 'hello world' via the Foo['bar'] defined type: Any additional information about valid values that is not clear from the data The special variables $title and $name are both set to the class name automatically, so they cant be used as parameters. This was the original reason for adding external data bindings to include-like declarations: since external data is set before compile-time and has a fixed hierarchy, the compiler can safely rely on it without risk of conflicts. Don't use class inheritance; use data binding instead of params.pp pattern. the character following it. easier to use. write, the $facts hash is clearer, easier to developing. Puppet by Perforce gives IT operations teams back their time and offers peace of mind with infrastructure automation that enables security and compliance. it appears, such as when it is very short. Resources are not subject to scope: a resource in any area of code can be referenced from any other area of code. parameters available. makes it available. See the documentation of the ENC interface or the documentation of your specific ENC for complete details. For details, see the Containing Classes section of the Containment page. can be overridden with Hiera. Smart Class parameters You can override parameters of a Puppet module using Smart Class parameters if the module supports the use of parameters. that represents the data type of these values at least one must be given, or an error of unsupported OS is raised. This style guide applies to Puppet 4 matter how many times you add the class, it is added to the catalog only once. To Comments must be hash comments (# This is a comment). specify the default values directly in the class or defined type. When using the special attribute * (asterisk or splat character) in In this example declaration, the it were a normal parameter. The parameters you added when defining the type, such as Resource-like class declarations When a class is declared, Puppet will try the following for each of its parameters: Resource-like class declarations require that you only declare a given class once. documentation tags @api private and @api public to make this clear. are mostly useful if you want to pass parameters to the class but can't or don't use Hiera. Some of the abstract Include-like declarations are the most common; they are flexible and 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. You can also specify a value for any metaparameter. that includes classes from every level of the hierarchy. Securing sensitive data in Puppet manifests directory of the module. Declaring a class in a Puppet Puppets behavior when declaring or assigning a class with both styles is undefined, and will sometimes work and sometimes cause compilation failures. You can also provide data types as both operands for the comparison operators ==, !=, <, >, <=, and >=, to test first attribute specified so that a user can quickly see if the resource is being created or Rather than the usual assignment statement, each instance of the defined type uses its An object holding a value to be passed as a parameter (for example, another IfxParameter instance, or instances of IBM.Data. Conditional statements should follow Puppet code guidelines. If you set a data type for each parameter, Puppet checks the used. Defined type names can consist of one or more namespace segments, which Store defined resource type manifests in the manifests/ directory of a module. Can be a simple object only having attributes, or a You can include any metaparameter in the declaration of a defined type instance. documentation. Case statements and selector expressions allow data types as Required Defined resource types This is functionally equivalent to doing the following: This is a significant readability win, especially if the amount of logic or the number of parameters grows beyond whats shown in the example. A string MUST be enclosed in double quotes if it: Contains escaped characters not supported by single-quoted strings. features. A type that represents all types not assignable from the. Click the Smart Class Parameter tab. Puppet parameter: See an issue? A class contains all Reference variables in a clear, unambiguous The values of If you need to use an anti-class pattern (e.g. Include usage examples and code samples for the common use cases for your language has a data type, like string. There is also a set of values whose data type is data type. These values represent the other statements and expressions. Metaparameters which can take more than one value (like the. For example: node default { class {'apt': always_update =>true } } class apt ($always_update = true ) { // code } node 'example.com' { class { bar: } } See puppet documentation for more information: parameters or conditional logic. Classes should be stored in their modules manifests/ directory as one class per file, and each filename should reflect the name of its class; see Module Fundamentals and Namespaces and Autoloading for more details. This form is sent to the Puppet docs team. If you need some classs resources declared before proceeding further, you can include it inside another classs definition. Or, if necessary, you can turn the 140 line character limit off. Puppet uses the Sensitive data type to mark your sensitive data for example secrets, passwords and private keys with a flag that hides the value from certain parts of Puppet, such as reports. Use semicolon-separated multiple resource bodies only in conjunction with a local default A variable name to represent the parameter, including the. 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. full benefit of your work. Parameters allow a class to request external data. format: Include comments for each element (classes, functions, defined types, parameters, and so Regardless of your preferred quoting style, all variables MUST be enclosed in braces when I'm trying to notify a class that I found, which runs update-rc.d with a parameter: define myclass::update-r. variables. catalog. defaults with Hiera data. representable in JSON. metaparameters, merge the values from the container and any specific values from the individual resource. ENC for details. resource contained in the class will also have that metaparameter. If the resource type includes a namespace separator ::, then each segment must be capitalized. always easy to detect. For more information on how Puppet uses your personal information, see Instead, use the template() and epp() functions to read a template from the module. This consistency in code and module structure makes it easier to update and maintain the code. No style guide can cover every circumstance you might run into when state of myservice, and creates a tempfile with given Should not exceed a 140-character line width, except where such a limit would be Next lines: Should override resources if necessary. You should avoid using calls to Hiera functions in modules meant for public consumption, Hashes resources of that defined type anywhere in your manifests. Must use one space between the resource type and opening brace, one space between the services needed to run an application. statement in a manifest (.pp) file. Parameter Data type Default value Description; 1: Key type: Type: Scalar: What kinds of values can be used as keys. Instead, we recommend using parameters that Accomplish other use cases by adding unique variable to avoid duplicate declarations. In the above example, Puppet will ensure that every resource in the apache class gets applied before every resource in any apache::vhost instance. Generally, your code expects each parameter to be a specific kind of data. The myservice class installs packages, ensures the Validations should validate also set, To use some attributes from a hash and override others, either use a hash to set If you tried to set, Abstract data types let you write more sophisticated and flexible restrictions. indentation: When using if/else statements, align in the following way: Your metadata should follow the following using the new declaration's values for the parameters. using the class pseudo-resource type. Select a class from the list that has parameters as indicated in the Parameters column. If a resource declaration includes an ensure attribute, it should be the 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. parameter accepts values of any data type. For example, if mode is present in the hash, you cant Enter your feedback and email. Puppet automatically loads any defined types that are present classes: Defining a class makes it available for later use. Every module must have metadata defined in the metadata.json file. to disable a service that is normally enabled), you can use a class parameter to override the standard behavior. Supply default values for parameters whenever possible. illegal value. specify them in the resource declaration, the default value is used. Resource attributes must be uniformly indented in two spaces from the title. Use backslash (\) as an escape character. encounter them in the code. If you specify a key type, a value type is mandatory. If used, documentation comments must precede the name of the For example, you can test whether When you have many interdependent or order-specific items, chaining syntax may be Puppet Strings generates a REFERENCE.md file containing all the reference information for your module, including a complete list of your module's classes, defined types, functions, resource types and providers, Puppet tasks and plans, along with parameters for each. documentation guide, list of includes the template. Classes are singletons although a given class can behave very differently We ask for your email as we might contact you regarding your feedback. assert_type Parameters and attributes $title and $name Defined resource types , sometimes called defined types or defines, are blocks of Puppet code that can be evaluated multiple times with different parameters. Must include trailing commas after all resource attributes and parameter For an example, see the rabbitmq module. include, require, contain, and Chapter 3. Adding Puppet Modules to Red Hat Satellite 6 selector expressions. When referencing facts, prefer the $facts hash to plain Separating into public and private classes or defined types ), Component versions in puppet-agent, Firewall quick start guide, About deprecations in this version, Overview of Puppet's architecture, File location changes since Puppet 3.8.x, Pre-upgrade tasks from 3.8, Upgrade agents from 3.8.x Puppet 5.x, Minor upgrades: From Puppet 4 and within Puppet 5.x, Short list of important settings, puppet.conf: The main config file, environment.conf: Per-environment settings, auth.conf (LEGACY): HTTPS authorization, fileserver.conf: Custom fileserver mount points, hiera.yaml: Data lookup configuration, autosign.conf: Basic certificate autosigning, csr_attributes.yaml: Certificate extensions, custom_trusted_oid_mapping.yaml: Short names for cert extension OIDs, device.conf: Network hardware access, routes.yaml: Advanced plugin routing, webserver.conf: Jetty web server config, web-routes.conf: Mount points for component services, ca.conf: CA service access control (deprecated), master.conf: Authorization by HTTP header (deprecated), product.conf: Configuring Product-level Interactions (optional), logback.xml: Logging level and location, Advanced logging configuration, Editing settings on the command line, Complete list of settings (configuration reference), Settings that differ under Puppet Server, Installing and managing modules from the command line, Configuring a Server with Passenger and Apache, The WEBrick Puppet master, Notable differences vs. the Apache/Passenger stack, Differing behavior in puppet.conf, Using an external certificate authority, Monitoring Puppet Server metrics, SSL problems with load-balanced PuppetDB servers (Server Certificate Keep the resources different across instances, include the value of $title or First and last lines used only for the syntax of that data type. Chaining If Be sure to declare the data type of parameters, as this provides automatic type To use a number Resource-like declarations use resource-like behavior. detailed documentation for your module. You can Your module should not be written This allows you to abandon node definitions and use Hiera like a lightweight ENC. You must not use dashes, as they are not Inheritance causes three things to happen: Class inheritance should be used very sparingly, generally only in the following situations: class example (String $my_param = $example::params::myparam) inherits example::params { }. nested block, place the hash rocket one space ahead of the longest attribute name. Puppet has two main ways to declare classes: include-like and duplicate class declarations and vendor lock-in. enforces ordering of classes. dollar sign (. impractical. @param service_ensure the wanted state of services. stored in modules and applied later when they are invoked by name. The built-in function The general form of a resource reference is: The resource type, capitalized. syntax validation. As an example, to include value. to every resource in the class. The right section contains the configuration options for the parameter selected. defined type causes Puppet to re-evaluate the block of code See the topics about containment and relationships for more Select a class from the list that has parameters as indicated in the Parameters column. 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. value of the, See an issue? Do not use /* */ comments in Puppet code. addition to other attributes, splat should be ordered last so that it is easy to see. Resource-like declarations Uses the override value from the declaration, if present. resource that makes up the instance. When you create a defined type, you can precede each parameter in the define statement with Puppet looks up the values for class parameters in Hiera, using the fully qualified name of the parameter (myclass::parameter_one) as a lookup key. rspec-puppet does not do the class name parsing and lookup that the Puppet parser would do for you. assertions. A soft dependency is a dependency that is only 4. To add the code to the catalog, you must declare one or more resources For example, a reference to the apache::vhost resource You can use parameters to restrict which values Class matches, but it will matches no values. Each new element line indented one level. The Puppet README template offers a basic format you can use. A special data type used to declare resources. Classes can be derived from other classes using the inherits keyword. and later. A comma-separated list of class names or class references. Data types are useful in parameter lists, match (=~) expressions, case statements, and you must include it as an explicit default: {} for clarity's sake. Resources contained in classes and defined types share the relationships of those classes and defined types. 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. For more information on how Puppet uses your personal information, see You puppet-quest-guide/defined_resource_types.md at master - Github data type. Each value must be a data type that matches the allowed values for that key. parameters are parameters that are not set to anything, including undef. This means any relationships formed with the class as a whole is extended If you need to read internal data from another class, you should generally use qualified variable names instead of assigning parent scopes. and displayed by Puppet Strings, GitHub, and the Puppet Forge. For more information on if/else statements, see Conditional Next lines, if applicable: Should declare local variables and perform variable code that can be evaluated multiple times with different parameters. See Adding Hiera data to a module for a detailed example showing how to replace The general form of a define statement is: This example creates a new resource type called, Just as with a normal resource type, you can declare resource defaults for a defined type. is because overridden values from the class declaration: When a class is declared with a resource-like declaration. name automatically, so you can't use them as parameters. sequence. parameters at compile time for any parameters you don't override, Puppet falls back to external data. parameter list. an Enum for input May align hash rockets (=>) within blocks of This style guide promotes consistent formatting in the Puppet language, giving you a common pattern, design, and Type It takes one mandatory parameter. a parameter receives an illegal value. Classes can also contain other classes, but you must manually specify that a class should be contained. attribute-value pairs. POSIX symbolic notation must be a string. source. An increase in 'z' indicates a patch: non-breaking bug fixes. as parameters so tags can be used to selectively collect by environment or custom fact. value for any of those attributes. Specifically call out backwards-incompatible changes. They can be added to a nodes catalog by either declaring them in your manifests or assigning them from an ENC. There are also a few less common uses for them. For details about updating existing params of String, because you might parameters: This declaration declares a class and specifies the version Split your module into public and private classes and defined types where possible. Arbitrary Next lines: Includes and validation come after parameters are defined. When defining variables you must only use You cannot set any attribute more than one time for a given resource; if you try, Puppet raises a compilation error. Your module must be versioned, and have metadata defined in the metadata.json file. For complete Note that most ENCs assign classes with include-like behavior, and some ENCs assign them with resource-like behavior. or relationship declarations. Parameters should be typed. These special variable names are protected; An optional parameter list, which consists of: A comma-separated list of parameters, such as, An optional data type, which restricts the allowed values Declaring classes isnt the only way to add them to the catalog; you can also assign classes to nodes with an ENC. maintaining older code. See Puppet ntp::service. If a class needs to use data other than privacy policy. It accepts a single lookup key. When you need to override resource attributes in the base class. This is a known bug. of the containing class extend to the contained class as well. The variables $title and $name are both set to the class classes in your module. If you leave us your email, we may contact you regarding your feedback. parameter_type. Puppet 3 is no longer supported, but we ntp class, that resource will also be applied before the error if the value is illegal. per-expression defaults, or use the. If you are maintaining old code created prior to Puppet 4.9, An increase in 'y' indicates minor changes: the non-breaking addition of new If you include a data type, Puppet Let's first create a parametrized class by creating a my_parameters module with the classes my_class and the usual main (my_parameters) class. A parameterized class enables other users of your code base to change the behavior and output of the class: external data or as an override. short or single purpose resource declarations on a single line. quote each title in the array, but cannot quote the array itself. This single class name declaration declares the class only once and has no additional declaring them in init.pp, but has the benefit of for the parameter. Resource declarations have a lot of possible features, so your code's Language: Classes Consistent module design practices makes module This means any relationships formed with the class as a whole will be extended to every resource in the class. automatically tagged with the name of its container. in the main manifest. Looking up data with Hiera We ask for your email as we might contact you regarding your feedback. Avoid legacy style defaults. Classes generally configure large or medium-sized chunks of Please note: In object-oriented languages, the concept of a class, template-like, is very different than Puppet's singleton-like implementation. If you need help with the product itself, visit, To learn about how Puppet uses your personal information, The parent type of all numeric data types. To send us feedback or let us know about a docs error, open a ticket (you need a Jira account) or leave a comment. This means that any of hex digits not equal to 4, use the longer u{digits} format. If no data type is provided, the parameter will accept values of any data type. our As such, you should supply defaults wherever possible. classes or defined types to manage their own dependencies and allows you create overlapping For both single- and double-quoted strings, escape the backslash to remove this special Classes can Avoid the inline_template() and inline_epp() functions for templates of more than one line, come before or after validation, but should be grouped separately, with all includes whitespace is allowed, but you cant have a trailing comma Structure classes and defined types to accomplish one task. Describe how to customize and configure the module. In nearly all other cases, inheritance is unnecessary complexity. alias. 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. Most ENCs assign classes with include-like behavior, but When a class is declared with an include-like declaration. example, String[8] is the data type of classs name and each of its namespace segments. Specify data types in your Puppet code whenever you can, aligning them in columns. defined type, it is included in all catalogs. If the tempfile contains digits, they are filtered out. overrides cause catalog compilation to be unreliable and dependent on order evaluation. privacy policy. Classes generally configure large or medium-sized chunks of functionality, such as all of the packages, config files, and services needed to run an application. The parent type of all types that are included in a Puppet containment, see the documentation on containing classes. hash. external data for parameters. Use Hiera data in your module to set parameter top-scope variables (such as $::operatingsystem). To satisfy cross-module dependencies in a more portable way, include statements Examples Hash matches a hash of any length; any keys must match Scalar and any values must match Data. To merge the defaults into those values, change the Specify data types as deeply as possible, without Purging resources in Puppet requires two conditions: a type which supports listing instances (at least one provider has a self.instances method defined) a parameter that can ensure the resource's absence When both these conditions are met, Puppet can purge the resources it doesn't explicitly manage by: Note that you can also use multi-resource references here.