[facts] use old-school fact naming convention for compatibility + lint

Author: truthbk

lib/facter/beta_repo.rb

@@ -1,4 +1,4 @@
-Facter.add('agent6_beta_repo') do
+Facter.add('apt_agent6_beta_repo') do
   setcode do
     File.exist? '/etc/apt/sources.list.d/datadog-beta.list'
   end

manifests/ubuntu.pp

@@ -33,8 +33,11 @@
   }
 
   # This is a hack - I'm not happy about it, but we should rarely
-  # hit this code path.
-  if $facts['agent6_beta_repo'] and $agent_version == 'latest' {
+  # hit this code path
+  #
+  # Also, using $::apt_agent6_beta_repo to access fact instead of
+  # $facts hash - for compatibility with puppet3.x default behavior
+  if $::apt_agent6_beta_repo and $agent_version == 'latest' {
     exec { 'datadog_apt-get_remove_agent6':
       command     => '/usr/bin/apt-get remove -y -q datadog-agent',
     }
@@ -47,22 +50,22 @@
     }
   }
 
-  if $facts['agent6_beta_repo'] {
+  if $::apt_agent6_beta_repo {
     file { '/etc/apt/sources.list.d/datadog-beta.list':
       ensure => absent,
     }
   }
 
   file { '/etc/apt/sources.list.d/datadog.list':
+    ensure  => file,
     owner   => 'root',
     group   => 'root',
-    ensure  => file,
     content => template('datadog_agent/datadog.list.erb'),
     notify  => [Exec['datadog_apt-get_remove_agent6'],
                 Exec['datadog_apt-get_update']],
     require => Package['apt-transport-https'],
   }
-  
+
   exec { 'datadog_apt-get_update':
     command     => '/usr/bin/apt-get update',
     refreshonly => true,
@@ -71,18 +74,17 @@
     require     => File['/etc/apt/sources.list.d/datadog.list'],
   }
 
-  
   package { 'datadog-agent-base':
     ensure => absent,
     before => Package['datadog-agent'],
   }
- 
+
   package { 'datadog-agent':
     ensure  => $agent_version,
     require => [File['/etc/apt/sources.list.d/datadog.list'],
                 Exec['datadog_apt-get_update']],
   }
- 
+
   service { 'datadog-agent':
     ensure    => $::datadog_agent::service_ensure,
     enable    => $::datadog_agent::service_enable,