A "thread pool" manager of DigitalOcean hosts. It can be used for on-demand CI workers, and runs on Heroku.There is an HTTP endpoint to GET a host, in which depending on pool size (concurrency) you may wait in line, but eventually wait while a host is provisioned. While you wait, the connection remains open. Once provisioned, the IP of the host is returned and the connection is closed. The provisioned host will automatically be destroyed after a timeout. Hostpool ensures only a certain number of hosts are active at any time.