As you're probably aware, we're putting a lot of effort into improving the Ceph
management and monitoring capabilities of openATTIC in collaboration with SUSE.
One of the challenges here is that Ceph is a distributed system, usually running
on a number of independent nodes/hosts. This can be somewhat of a challenge for
a developer who just wants to "talk" to a Ceph cluster without actually having
to fully set up and manage it.
Of course, you could be using tools like SUSE's Salt-based DeepSea project or ceph-ansible, which automate the deployment and
configuration of an entire Ceph cluster to a high degree. But that still
requires setting up multiple (virtual) machines, which could be a daunting or at
least resource-intensive task for a developer.
While we do have a number of internal Ceph clusters in our data center that we
can use for testing and development purposes, sometimes it's sufficient to have
something that behaves like a Ceph cluster from an API perspective, but must not
necessarily perform like a full-blown distributed system (and can be set up
Fortunately, Docker comes to the rescue here - the
nice folks at Ceph kindly provide a special Docker image labeled ceph/demo, which can be described as a "Ceph
cluster in a box".