are there iterators and loops in puppet?

Question

When I define(?) a resource e.g. to ensure dir structure, are there any loops available?

Like that:

  for X in [app1,app2] do:     file { '/opt/app/' + X:       ensure => directory,       owner  => 'root',       group  => 'root',       mode   => '0644',     } 

I have tens of directories and I am really tired with declaring it in puppet.. It would take 15 LOC of bash.

Any ideas?

Answer 1

Older versions of the puppet language have no support for loops.

But you can use an array instead of a simple string for the title and declare several resources at the same time with the same params:

$b = '/opt/app' file { [ "$b/app1", "$b/app2" ]:   ensure => directory,   owner  => 'root',   group  => 'root',   mode   => 0644, } 

You can also declare many resources of the same type with different params by ending each resource with a ;, which is a bit more compact than repeating the file and the {s and }s:

file {   [ "$b/app1", "$b/app2" ]:     ensure => directory,     owner  => 'root',     group  => 'root',     mode   => 0755;   [ "$b/app1/secret", "$b/app2/secret" ]:     ensure => directory,     owner  => 'root',     group  => 'root',     mode   => 0700; } 

In the specific case of files, you can set up a source and use recursion:

file { "/opt/app":   source => "puppet:///appsmodule/appsdir",   recurse => true; } 

(that would require having a source of that directory structure for puppet to use as the source)

You can define a new resource type to reuse a portion of the param multiple times:

define foo {   file {     "/tmp/app/${title}":       ensure => directory,       owner  => 'root',       mode   => 0755;     "/tmp/otherapp/${title}":       ensure => link,       target => "/tmp/app/${title}",       require => File["/tmp/app/${title}"]   } }  foo { ["app1", "app2", "app3", "app4"]: }  

Starting with Puppet 2.6, there's a Ruby DSL available that has all the looping functionality you could ask for: http://www.puppetlabs.com/blog/ruby-dsl/ (I've never used it, however). In Puppet 3.2, they introduced some experimental loops, however those features may change or go away in later releases.