ceph-qa-suite
-------------

clusters/    - some predefined cluster layouts
tasks/       - some predefined task fragments
collections/ - collections of tests to actually run

We have several collections, each a subdirectory within collections/.
Each collection directory consists of a set facets.  The basic idea is
that, for each collection, the set of tests to run consists of all
combinations of taking one yaml fragment from each facet.

For example, given the files

  collections/
  collections/foo/
  collections/foo/clusters/
  collections/foo/clusters/fixed-3.yaml
  collections/foo/clusters/fixed-9.yaml
  collections/foo/tasks/
  collections/foo/tasks/a
  collections/foo/tasks/b
  collections/foo/tasks/c
  collections/bar/
  collections/bar/clusters/fixed-3.yaml
  collections/bar/tasks/
  collections/bar/tasks/d
  collections/bar/tasks/e

teuthology-suite would run tasks a, b, and c on both fixed-3 and
fixed-9 clusters.  It would also run tasks d and e on the fixed-3
cluster.

Note that the 'clusters' and 'tasks' terminology is actually
meaningless here.  All teuthology-suite does is stick the yaml
fragments together (one from each facet) and run teuthology on the
result (optionally combined with any additional fragments passed on
the command line).

In practice, we can keep common/shared task and cluster definitions in
the top-level clusters/ and tasks/ directories (which are otherwise
ignored), and symlink to them from the collections that want to use
them.