GOPA
GOPA, a spider written in Golang, for Elasticsearch
...First of all, get it, two opinions: download the pre-built package or compile it yourself. Besides Elasticsearch, Gopa doesn't require any other dependencies, just simply run ./gopa to start the program. It's safety to press ctrl+c to stop the current running Gopa, Gopa will handle the rest, saving the checkpoint, you may restore the job later, but the world is still in your hand.