Merge pull request #86 from bodepd/ensure_resource

Add function ensure_resource and defined_with_params

2 files changed, 68 insertions, 0 deletions

diff --git a/lib/puppet/parser/functions/defined_with_params.rb b/lib/puppet/parser/functions/defined_with_params.rb
new file mode 100644
index 0000000..d7df306
--- /dev/null
+++ b/lib/puppet/parser/functions/defined_with_params.rb
@@ -0,0 +1,35 @@
+# Test whether a given class or definition is defined
+require 'puppet/parser/functions'
+
+Puppet::Parser::Functions.newfunction(:defined_with_params,
+                                      :type => :rvalue,
+                                      :doc => <<-'ENDOFDOC'
+Takes a resource reference and an optional hash of attributes.
+
+Returns true if a resource with the specified attributes has already been added
+to the catalog, and false otherwise.
+
+    user { 'dan':
+      ensure => present,
+    }
+
+    if ! defined_with_params(User[dan], {'ensure' => 'present' }) {
+      user { 'dan': ensure => present, }
+    }
+ENDOFDOC
+) do |vals|
+  reference, params = vals
+  raise(ArgumentError, 'Must specify a reference') unless reference
+  if (! params) || params == ''
+    params = {}
+  end
+  ret = false
+  if resource = findresource(reference.to_s)
+    matches = params.collect do |key, value|
+      resource[key] == value
+    end
+    ret = params.empty? || !matches.include?(false)
+  end
+  Puppet.debug("Resource #{reference} was not determined to be defined")
+  ret
+end
diff --git a/lib/puppet/parser/functions/ensure_resource.rb b/lib/puppet/parser/functions/ensure_resource.rb
new file mode 100644
index 0000000..6a9e2ed
--- /dev/null
+++ b/lib/puppet/parser/functions/ensure_resource.rb
@@ -0,0 +1,33 @@
+# 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.
+
+ENDOFDOC
+) do |vals|
+  type, title, params = vals
+  raise(ArgumentError, 'Must specify a type') unless type
+  raise(ArgumentError, 'Must specify a title') unless title
+  params ||= {}
+  if function_defined_with_params(["#{type}[#{title}]", params])
+    Puppet.debug("Resource #{type}[#{title}] not created b/c it already exists")
+  else
+    function_create_resources([type.capitalize, { title => params }])
+  end
+end