1 files changed, 45 insertions, 0 deletions
diff --git a/lib/puppet/parser/functions/ensure_resource.rb b/lib/puppet/parser/functions/ensure_resource.rb
new file mode 100644
index 0000000..a9a1733
--- /dev/null
+++ b/lib/puppet/parser/functions/ensure_resource.rb
@@ -0,0 +1,45 @@
+# Test whether a given class or definition is defined
+require 'puppet/parser/functions'
+
+Puppet::Parser::Functions.newfunction(:ensure_resource,
+                                      :type => :statement,
+                                      :doc => <<-'ENDOFDOC'
+Takes a resource type, title, and a list of attributes that describe a
+resource.
+
+    user { 'dan':
+      ensure => present,
+    }
+
+This example only creates the resource if it does not already exist:
+
+    ensure_resource('user, 'dan', {'ensure' => 'present' })
+
+If the resource already exists but does not match the specified parameters,
+this function will attempt to recreate the resource leading to a duplicate
+resource definition error.
+
+An array of resources can also be passed in and each will be created with
+the type and parameters specified if it doesn't already exist.
+
+    ensure_resource('user', ['dan','alex'], {'ensure' => 'present'})
+
+ENDOFDOC
+) do |vals|
+  type, title, params = vals
+  raise(ArgumentError, 'Must specify a type') unless type
+  raise(ArgumentError, 'Must specify a title') unless title
+  params ||= {}
+
+  items = [title].flatten
+
+  items.each do |item|
+    Puppet::Parser::Functions.function(:defined_with_params)
+    if function_defined_with_params(["#{type}[#{item}]", params])
+      Puppet.debug("Resource #{type}[#{item}] not created because it already exists")
+    else
+      Puppet::Parser::Functions.function(:create_resources)
+      function_create_resources([type.capitalize, { item => params }])
+    end
+  end
+end