目前puppet2.7以上版本都支持if...elif ...else...、selecter和case语句.它们的条件判断分为两类:一类为条件执行(if...elif ...else...、selecter)通过逻辑判断来选择要执行的特定代码或加载代码;另一类(case)是循环执行类,依照代码规则来执行代码或加载代码.

if条件判断语句:

示例一:


if判断系统发行版本安装apache软件包:

[root@sh-web1 ~]# cat apache.pp 
if $operatingsystem == 'CentOS' {
    $packages = 'httpd'
} elsif $operatingsystem == 'Redhat' {
    $packages = 'httpd'
} else {
    $packages = 'apache2'
}
    package {"$packages":
    ensure=> "present",
}

本地应用puppet代码:

[root@sh-web1 ~]# puppet apply apache.pp 
Notice: Compiled catalog for sh-web1.localdomain in environment production in 0.04 seconds
Notice: /Stage[main]/Main/Package[httpd]/ensure: created
Notice: Finished catalog run in 1.78 seconds

注意:"=="是等于的意思，完完全全匹配到对应的.


示例二:

if匹配hostname主机载入相应的puppet模块.(if在node.pp文件中匹配主机很少用,几乎都是用case.)

node base {
    include admin
}
node /sh-(proxy|web)\d+/  inherits base {
    if $hostname =~ /sh-proxy\d+/ {
        include apache
    } elsif $hostname =~ /sh-web\d+/ {
        include php
    } else {
        include nginx::nginxconf
    }
}


agent端更新puppet代码.

[root@sh-proxy2 ~]# puppet agent -t
Info: Retrieving pluginfacts
Info: Retrieving plugin
Info: Loading facts
Info: Caching catalog for sh-proxy2.localdomain
Info: Applying configuration version '1506450177'
Notice: /Stage[main]/Admin/Exec[selinux]/returns: executed successfully
Notice: /Stage[main]/Install/Package[httpd]/ensure: created
Notice: /Stage[main]/Service/Service[httpd]/ensure: ensure changed 'stopped' to 'running'
Info: /Service[httpd]: Unscheduling refresh on Service[httpd]
Notice: Finished catalog run in 20.24 seconds


agent端更新puppet代码.

[root@sh-web1 ~]# puppet agent -t
Notice: Ignoring --listen on onetime run
Info: Retrieving pluginfacts
Info: Retrieving plugin
Info: Loading facts
Info: Caching catalog for sh-web1.localdomain
Info: Applying configuration version '1506450177'
Notice: /Stage[main]/Admin/Exec[selinux]/returns: executed successfully
Notice: /Stage[main]/Php/Package[php]/ensure: created
Notice: /Stage[main]/Php/Package[php-devel]/ensure: created
Notice: Finished catalog run in 4.01 seconds

注意:"=~"是匹配的意思，只要匹配到就行.


case语句应用:

示例:(之前文章一直都在用的匹配方法case)


node base {
include admin
}
node /sh-(proxy|web)\d+/  inherits base {
  case $::hostname {
    /sh-proxy\d+/: {
         include apache
      }
     "sh-web1": {
            include nginx::nginxconf
            include php
         } 
    }
}


agent端更新就不演示了,上面的case语句博客开始就是这样写的.