Wondering which cap it could be?
....Well its Capistrano :D
I am a fan of Capistrano from way back and we use it for almost all kind of deployments - Hadoop, MongoDB clusters and so on.
If you have not tried Capistrano, you must try it and figure out how you can use for deployments in your environment.
Its highly configurable - so capify your stuffs!
Checkout the capified scripts to Deploy a replicated sharded MongoDB cluster on AWS EC2 instances in the following link
Feel free to experiment, report bugs/ issues and contribute back.
For more details, follow the link below :