木偶 - 课程

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Puppet 类被定义为资源的集合，这些资源被分组在一起以便使目标节点或机器处于所需的状态。这些类在位于 Puppet 模块内的 Puppet 清单文件中定义。使用类的主要目的是减少任何清单文件或任何其他 Puppet 代码中的相同代码重复。

以下是 Puppet 类的示例。

[root@puppetmaster manifests]# cat site.pp  
class f3backup ( 
   $backup_home   = '/backup', 
   $backup_server = 'default', 
   $myname        = $::fqdn, 
   $ensure        = 'directory', 
) { 
   include '::f3backup::common' 
   if ( $myname == '' or $myname == undef ) { 
      fail('myname must not be empty') 
   }  
   @@file { "${backup_home}/f3backup/${myname}": 
      # To support 'absent', though force will be needed 
      ensure => $ensure, 
      owner  => 'backup', 
      group  => 'backup', 
      mode   => '0644', 
      tag    => "f3backup-${backup_server}", 
   }
}   

在上面的示例中，我们有两个需要用户存在的客户端。可以注意到，我们已经重复了相同的资源两次。组合两个节点时不执行相同任务的一种方法。

[root@puppetmaster manifests]# cat site.pp 
node 'Brcleprod001','Brcleprod002' { 
   user { 'vipin': 
      ensure => present, 
      uid    => '101', 
      shell  => '/bin/bash', 
      home   => '/home/homer', 
   } 
}

以这种方式合并节点来执行配置并不是一个好的做法。这可以通过创建一个类并将创建的类包含在节点中来简单地实现，如下所示。

class vipin_g01063908 { 
   user { 'g01063908': 
      ensure => present, 
      uid    => '101', 
      shell  => '/bin/bash', 
      home   => '/home/g01063908', 
   } 
}  
node 'Brcleprod001' { 
   class {vipin_g01063908:} 
}  
node 'Brcleprod002' { 
   class {vipin_g01063908:} 
}

需要注意的一点是类结构的样子以及我们如何使用 class 关键字添加新资源。Puppet 中的每种语法都有自己的特点。因此，选择的语法取决于条件。

参数化类

如上面的示例所示，我们已经了解了如何创建类并将其包含在节点中。现在有些情况我们需要在每个节点上有不同的配置，例如需要在每个节点上有不同的用户使用相同的类。Puppet 中使用参数化类提供此功能。新类的配置将如以下示例所示。

[root@puppetmaster ~]# cat /etc/puppet/manifests/site.pp 
class user_account ($username){ 
   user { $username: 
      ensure => present, 
      uid    => '101', 
      shell  => '/bin/bash', 
      home   => "/home/$username", 
   } 
}  
node 'Brcleprod002' { 
   class { user_account: 
      username => "G01063908", 
   } 
} 
node 'Brcleprod002' { 
   class {user_account: 
      username => "G01063909", 
   } 
} 

当我们在节点上应用上述 site.pp 清单时，每个节点的输出将如下所示。

Brcleprod001

[root@puppetagent1 ~]# puppet agent --test 
Info: Retrieving pluginfacts 
Info: Retrieving plugin 
Info: Caching catalog for puppetagent1.testing.dyndns.org 
Info: Applying configuration version '1419452655' 

Notice: /Stage[main]/User_account/User[homer]/ensure: created 
Notice: Finished catalog run in 0.15 seconds 
[root@brcleprod001 ~]# cat /etc/passwd | grep "vipin" 
G01063908:x:101:501::/home/G01063909:/bin/bash 

Brcleprod002

[root@Brcleprod002 ~]# puppet agent --test 
Info: Retrieving pluginfacts 
Info: Retrieving plugin 
Info: Caching catalog for puppetagent2.testing.dyndns.org 
Info: Applying configuration version '1419452725' 

Notice: /Stage[main]/User_account/User[bart]/ensure: created 
Notice: Finished catalog run in 0.19 seconds 
[root@puppetagent2 ~]# cat /etc/passwd | grep "varsha" 
G01063909:x:101:501::/home/G01063909:/bin/bash

还可以设置类参数的默认值，如以下代码所示。

[root@puppetmaster ~]# cat /etc/puppet/manifests/site.pp 
class user_account ($username = ‘g01063908'){ 
   user { $username: 
      ensure => present, 
      uid    => '101', 
      shell  => '/bin/bash', 
      home   => "/home/$username", 
   } 
}  
node 'Brcleprod001' { 
   class {user_account:} 
}  
node 'Brcleprod002' { 
   class {user_account: 
      username => "g01063909", 
   } 
}