(5909) Function to dyncamically generate resources.

This function allows you to dynamically generate resources,
passing them as a hash to the create_resources function.

This was originally written to be used together with an ENC.

Resources can be programitally generated as yaml and passed to a class.

classes:
  webserver::instances:
    instances:
      instance1:
        foo: bar
      instance2:
        foo: blah

Then puppet code can consume the hash parameters and convert then into resources

class webserver::instances (
  $instances = {}
) {
  create_resources('webserver::instance', $instances)
}

Now I can dynamically determine how webserver instances are deployed to nodes
by updating the YAML files.

1 files changed, 47 insertions, 0 deletions

diff --git a/lib/puppet/parser/functions/create_resources.rb b/lib/puppet/parser/functions/create_resources.rb
new file mode 100644
index 000000000..430f110b4
--- /dev/null
+++ b/lib/puppet/parser/functions/create_resources.rb
@@ -0,0 +1,47 @@
+Puppet::Parser::Functions::newfunction(:create_resources, :doc => '
+Converts a hash into a set of resources and adds them to the catalog.
+Takes two parameters:
+  create_resource($type, $resources)
+    Creates resources of type $type from the $resources hash. Assumes that
+    hash is in the following form:
+     {title=>{parameters}}
+  This is currently tested for defined resources, classes, as well as native types
+') do |args|
+  raise ArgumentError, ("create_resources(): wrong number of arguments (#{args.length}; must be 2)") if args.length != 2
+  #raise ArgumentError, 'requires resource type and param hash' if args.size < 2
+  # figure out what kind of resource we are
+  type_of_resource = nil
+  type_name = args[0].downcase
+  if type_name == 'class'
+    type_of_resource = :class
+  else
+    if resource = Puppet::Type.type(type_name.to_sym)
+      type_of_resource = :type
+    elsif resource = find_definition(type_name.downcase)
+      type_of_resource = :define
+    else 
+      raise ArgumentError, "could not create resource of unknown type #{type_name}"
+    end
+  end
+  # iterate through the resources to create
+  args[1].each do |title, params|
+    raise ArgumentError, 'params should not contain title' if(params['title'])
+    case type_of_resource
+    when :type
+      res = resource.hash2resource(params.merge(:title => title))
+      catalog.add_resource(res)
+    when :define
+      p_resource = Puppet::Parser::Resource.new(type_name, title, :scope => self, :source => resource)
+      params.merge(:name => title).each do |k,v|
+        p_resource.set_parameter(k,v)
+      end
+      resource.instantiate_resource(self, p_resource)
+      compiler.add_resource(self, p_resource)
+    when :class
+      klass = find_hostclass(title)
+      raise ArgumentError, "could not find hostclass #{title}" unless klass
+      klass.ensure_in_catalog(self, params)
+      compiler.catalog.add_class([title])
+    end
+  end
+end