Note: This script will build and install the plugin assuming elasticsearch is found in /usr/share/elasticsearch. The script will call 'sudo' on the install part, so the script should be run as a user with sudo privileges. Since maven will be used to build the plugin, it requires maven to be installed, which can be installed with the command below on a debian/ubuntu system. This refeeds all documents in index 'indexold' with type 'typeold' into the index 'indexnew' with type 'typenew'. But only documents matching the specified filter will be refeeded. The internal Java API will be used which should be efficient. In this example, the term filter is used to limit the documents that will be reindexed, you can leave out the filter to copy all documents to the new index.