Keystone Federated Swift – A series of posts

Matt Treinish and I proposed a presentation at the OpenStack Summit in Vancouver in May, it was accepted but on standby. Which simply means we have a lightening talk slot (10 minutes), but may be bumped up to a full slot based on how other presenters go (visa issues, pull outs, etc).

Anyway, 10 minutes wont do the topic justice, so I thought what better then to also post details as I work through them here. Some of what I say may end up in the presentation, or may not. All I know is I’ve been asked a few times how to setup Swift in a Keystone federated environment. Let’s face it, Swift scales to a global cluster no worries, however other OpenStack components may have trouble doing the same. So federating a bunch of different regions and treating them as their own clouds makes heaps of sense. Great, then what’s the best way of integrating Swift into this federated environment?


My current Idea is to walk through 3 initial topologies. The first I’ll call ‘false federation’ where we can simply use Swift’s ability to use multiple authentication middlewares as different resellers to be able to authenticate to multiple keystone endpoints. For those playing along at home, the keystone middleware currently doesn’t let you do this, but I have a trivial patch that fixes this.. and plan to push it upstream as soon as I have a chance to clean it up and add tests.


The second, is separate swift clusters in each cloud. But using Swifts container sync to move objects so you still have access to your data on any cloud you visit… eventually.


And finally the third is what we’d all want, I large swift cluster, that all clouds talk to, so no matter where you are, there your data is. Plus gives better durability, dispersion, and everything we want out of a Swift cluster. The trick here will be making sure the same swift account name is used no matter which keystone your talk to, and assume this will come down to how you configure what you share during federated token exchange. I’ll leave this as the last post and we still need to play to iron it out.. but obviously is the dream.

These diagrams are obviously overly simplistic, but I hope you get the idea.

The next post will be the ‘False federation’ approach seeing as I already have a swift keystoneauth middleware patch that solves this.

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