Mythic Beasts is an awesome hosting company based in Cambridge. They host the Raspberry Pi website, including the Raspbian archive and download images, and like to make sure we eat our own dog food by hosting the website on new Raspberry Pi hardware for product launches.
Mythic built a Raspberry Pi server rack in their London data centre, affectionately known and marketed as the Pi cloud. It’s a sophisticated system for centrally managing Raspberry Pis using PoE and netboot. Rather than using SD cards with Pis, they use one of the Pi 3’s alternative booting options: PXE. You get partitioned some disk space on an NFS mount, and this contains your OS and files. 10GB is the default, but you can get more if you want.
It takes less than five minutes to register a Pi and SSH onto it. Start here, click all the right buttons, and paste in an SSH key at the end. It’ll tell you which SSH port to use, as they have an IPv4to-v6 proxy so that each Pi doesn’t need its own IPv4 address (that would cost half the price of a Pi!).
You can choose to reimage a Pi server at any time, either to start from scratch, or to choose a new distro or version. You can choose between Raspbian Jessie, Stretch and Buster, and Ubuntu Xenial and Bionic. As of today, the default is Buster.
The Pis in the datacentre are 3B and recently they added some 3B+. It’s random what you get, but I think your chances of getting a 3B+ are high based on current usage of 3B.
The main benefit of Pi hosting is if you need to run your code on real Raspberry Pi hardware, without emulation. You can run real web apps or host a website if you want; though I don’t think that’s a practical option until the Pi 4 rolls out. Static sites actually run pretty well served from the Pi. piwheels.org is hosted on a single cloud Pi (3B) and that serves between 500k and 900k files per month.
It’s no secret I’m a big user of the Pi cloud. I run the piwheels project, which is run almost entirely on cloud Pis (we had to move the postgres database onto a VM as it kept running out of RAM – and swap over NFS is no fun). Once netboot support is added to Raspberry Pi 4, I can see Mythic promptly adding Pi 4s to the rack. Exciting times ahead! That should mean we can move the piwheels database back to a Pi, as long as it’s one with plenty of RAM!
Update: I’ve now also made a screencast of this process: