To add an attribute to an existing Chef Server node, the handler uses Chef's REST API. The handler first retrieves the users private key from the specified location so that it can then be used to sign the REST request. The handler then retrieves the node that will be updated to get all of the attributes that are currently attached to it. The inputted Attribute Name and Attribute Value will then be added as a key/value pair to the 'normal' attribute object in the node object. That updated object is then re-posted to the Chef Server to apply the changes to the node attributes on the Chef Server. And errors that are encountered during the process are caught and re-rasied by the handler.
Name of the node that the attribute will be added to.