Hey!
I'm not sure it's worth doing. While I don't think this is a bad idea, I can't find any real gains to a shared instance in an Openshift world. I do see a few downsides though: - You'll need to share the same redis password across several projects. I see that as a potential security issue. - Since you'll use an emptyDir (in-memory storage), every restart will flush the cache for all connected applications. - Applications owners lose control over the redis instance in case they want to do some fancy stuff with it, or just general debugging.
The resource footprint of a redis container is quite low. We have a couple of redis pods deployed already, and the memory usage for some of them is as low as 14Mb.