[![Docker Repository on Quay.io](https://quay.io/repository/jzelinskie/chihaya/status "Docker Repository on Quay.io")](https://quay.io/repository/jzelinskie/chihaya)
BitTorrent clients send announce and scrape requests to a _Frontend_.
Frontends parse requests and write responses for the particular protocol they implement.
The _TrackerLogic_ interface to is used to generate responses for their requests and optionally perform a task after responding to a client.
A configurable chain of _PreHook_ and _PostHook_ middleware is used to construct an instance of TrackerLogic.
PreHooks are middleware that are executed before the response has been written.
The final middleware in a chain of PreHooks ensures the existance of any required response fields by reading out of the configured implementation of the _Storage_ interface.
PostHooks are asynchronous tasks that occur after a response has been delivered to the client.
Request data is written to storage asynchronously in one of these PostHooks.
[Facebook] uses BitTorrent to deploy new versions of their software.
In order to optimize the flow of traffic within their datacenters, Chihaya is configured to prefer peers within the same subnet.
Because Facebook organizes their network such that server racks are allocated IP addresses in the same subnet, the vast majority of deployment traffic never impacts the congested areas of their network.
[Facebook]: https://facebook.com
### CoreOS
[Quay] is a container registry that offers the ability to download containers via BitTorrent in order to speed up large or geographically distant deployments.
Announce URLs from Quay's torrent files contain a [JWT] in order to allow Chihaya to verify that an infohash was approved by the registry.
By verifying the infohash, Quay can be sure that only their content is being shared by their tracker.