Puppet Type/Provider: Simple

provider_simple.rb

# Simple Provider

require 'fileutils'
Puppet::Type.type(:simple).provide(:simple) do
  desc "Provides simple useless file creation"

  def create
    notice("Creating: #{resource[:name]}")
    system('/usr/bin/touch', "#{resource[:path]}/#{resource[:name]}")
  end

  def destroy
    notice("Destroying: #{resource[:name]}")
    system("/bin/rm", "#{resource[:path]}/#{resource[:name]}")
  end      

  def exists?
    notice("Checking for existence of: #{resource[:name]}")
    File.exists?("#{resource[:path]}/#{resource[:name]}")
  end
  
end

simple.pp

# simple.pp

simple { 'some_useless_file':
  path   => '/tmp',
  ensure => 'present',
}

type_simple.rb

# Simple Type

Puppet::Type.newtype(:simple) do
  @doc = "Create useless files for demonstration"
  ensurable

  newparam(:name) do
    desc "Name of the file to create"         
    isnamevar    
  end

  newparam(:path) do     
    desc "Path at which to create the file"
  end
  
end

NOTE: The file names listed here have their respective directory appended to the original name as "directory_" to avoid Gist conflict.

Master: Puppet 2.7.11 on Ubuntu 11.04
Client: Puppet 2.7.11 on Mac OS X 10.7.2

Running a puppet agent -t the first time produces the expected result. However, subsequent execs of puppet agent -t produce...

info: Caching catalog for some.host.com info: Applying configuration version '1335888340' err: /Stage[main]//Node[van-daphne.ucs.sfu.ca]/Simple[a_useless_file]: Could not evaluate: No ability to determine if simple exists notice: Finished catalog run in 0.08 seconds
Everytime. No matter how times I reboot the server or client, I get the same result -- apply once, fail thereafter.

If I purge /var/lib/puppet, puppet agent will again run again without error, but (again) ONLY ONCE!

My 2p: Try not to use system() from a provider unless you absolutely have to (each new fork() == a pain). In other words, provided that you have already required FileUtils, I do recommend you use FileUtils#touch and FileUtils#remove (or File#unlink) :)

Noted. Thanks.

You can also use Puppet::Util::Execute rather than system directly and get exception handling and a lot more, although it does look correct to use touch/unlink in this case.

What is the difference between Puppet::Util::Execute and declaring something like this... commands :touch => '/usr/bin/touch' In the provider? Is it functionally equivalent?

…

On 2012-05-02, at 7:42 PM, Luke Kanies wrote: You can also use Puppet::Util::Execute rather than system directly and get exception handling and a lot more, although it does look correct to use touch/unlink in this case. --- Reply to this email directly or view it on GitHub: https://gist.github.com/2569267

Using 'commands' is much better, actually - you get automatic validation of the provider (e.g., the provider fails if commands are missing, and you can run tests to determine if the provider is functional). You're right, actually, that using 'execute' should be very rare.

On May 3, 2012, at 8:04 AM, Brian Warsing wrote: What is the difference between Puppet::Util::Execute and declaring something like this... commands :touch => '/usr/bin/touch' In the provider? Is it functionally equivalent? On 2012-05-02, at 7:42 PM, Luke Kanies wrote: > You can also use Puppet::Util::Execute rather than system directly and get exception handling and a lot more, although it does look correct to use touch/unlink in this case. > --- > > Reply to this email directly or view it on GitHub: > https://gist.github.com/2569267 --- Reply to this email directly or view it on GitHub: https://gist.github.com/2569267

## Luke Kanies | http://about.me/lak | http://puppetlabs.com/ | +1-615-594-8199

Thanks for the tip.