Puppet: Test if Resource is defined, or create it

Question

I've been trying to figure out a way to test if a resource is already defined in another file, and if not create it? A quick example:

  if File[$local_container] {
    alert("Testing - It existed $local_container")
  } else {
    file{ "$local_container":
      ensure => directory,
    }
  }

However - File[$local_container] always seems to evaluate to true. Is there a way to do this?

score 15 · Answer 1 · edited Mar 19 '17 at 13:17

Do you mean "test if a resource is already defined"? If you define a resource (ie, file {}, etc) Puppet will create what you're describing if doesn't already exist (assuming you pass ensure => present, of course).

To check if a resource is already defined in the catalog or not:

mark-draytons-macbook:~ mark$ cat test.pp 
file { "/tmp/foo": ensure => present }

if defined(File["/tmp/foo"]) {
  alert("/tmp/foo is defined")
} else {
  alert("/tmp/foo is not defined")
}

if defined(File["/tmp/bar"]) {
  alert("/tmp/bar is defined")
} else {
  alert("/tmp/bar is not defined")
}

mark-draytons-macbook:~ mark$ puppet test.pp 
alert: Scope(Class[main]): /tmp/foo is defined
alert: Scope(Class[main]): /tmp/bar is not defined
notice: //File[/tmp/foo]/ensure: created

Note: defined() is dependent on parse order.

That "depends on parse order" part makes it almost useless. – joerx Apr 01 '14 at 02:47 — joerx, Apr 01 '14 at 02:47

score 10 · Accepted Answer · answered Jan 19 '15 at 10:56

10

The better way of doing this is by making use of ensure_resource function from puppetlabs stdlib

It takes a resource type, title, and a list of attributes that describe a resource as parameters.

say you have test case to only create the resource if it does not already exist-

ensure_resource('package', 'test-pkg', {'ensure' => 'present'})

answered Jan 19 '15 at 10:56

Utkarsh

216
2
5

This seems much cleaner, passing the checkmark this way. Thanks for the tip! – gnarf Jan 25 '15 at 15:25

score 2 · Answer 3 · answered Nov 05 '14 at 22:19

2

Or....

unless File["${local_container}"] {
  file{ "${local_container}":
     ensure => directory,
  }
}

And do keep an eye on those quotes and curly braces....

answered Nov 05 '14 at 22:19

nzidol

21
1

score -3 · Answer 4 · edited Jun 03 '14 at 09:51

-3

simply,

file{ "$local_container":
  ensure => directory,
  replace => false,
}

edited Jun 03 '14 at 09:51

Michael Hampton

244,070
43
506
972

answered Jun 03 '14 at 09:32

guest_002

5

Nope, if the `"$local_container"` file was already defined somewhere else (like say by something that wanted to control the permissions/owner) you can't define the same resource twice. – gnarf Jun 03 '14 at 18:37

Puppet: Test if Resource is defined, or create it

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