木偶EXEC鏈

Question

我需要的是這個...

1. look for changes to /tmp/file-1 file 
    a. if there is a change, execute in the following order 
     i. run cmd-3 
     ii. run cmd-2 
     iii. run cmd-1 
    b. If there is NO change to /tmp/file-1 file, do not run anything 

我的代碼是這樣的...

exec { 'exec-3': 
    command => "sudo cmd-3", 
    path => '/usr/local/bin', 
    require => File["/tmp/file-1"], 
} 

exec { 'exec-2': 
    command => "sudo cmd-2", 
    path => '/usr/local/bin', 
    require => Exec['exec-3'], 
} 

exec { 'exec-1': 
    command  => "sudo cmd-1", 
    path  => '/usr/local/bin', 
    require  => Exec['exec-2'], 
    subscribe => File["/tmp/file-1"], 
    refreshonly => true, 
} 

但是，是否有改變到/ tmp /文件-1或不，cmd-3和cmd-2總是運行。我如何防止它？當不改變/ tmp/file-1時，我不希望在exec-1中運行「require」。

Answer 1

您需要：首先，爲所有的exec訂閱文件資源;其次，每個人也需要他們先前的執行資源;第三，每位執行人員設置爲refreshonly。

下面是一些代碼，做的是：

Exec { 
    path => '/usr/local/bin', 
    refreshonly => true, 
} 

file { '/tmp/file-1': 
    ensure => file, 
    content => "file-1-content\n", 
} 

exec { 'exec-1': 
    command => 'sudo cmd-1', 
    subscribe => File['/tmp/file-1'], 
} 
exec { 'exec-2': 
    command => 'sudo cmd-2', 
    subscribe => File['/tmp/file-1'], 
    require => Exec['exec-1'], 
} 
exec { 'exec-3': 
    command => 'sudo cmd-3', 
    subscribe => File['/tmp/file-1'], 
    require => Exec['exec-2'], 
} 

注意，我還重構了一點使用資源的默認值（ref）不必要的重複，改變每風格指南（ref）的引用。