Ceph

When a parameter is missing from an erasure-code-profile (ruleset-failure-domain for instance) it falls back to the default of the plugin. The defaults are documented ( http://ceph.com/docs/master/rados/operations/erasure-code-isa/ for instance ) but they do not show when displaying the erasure-code-profile which is confusing for the user.

The get erasure-code-profile should display both the content of the profile and the parameters that are set implicitly by the plugin.

An method should be added to the interface of plugins to validate an erasure code profile and add the default values. This would also make the stored profile less fragile because it would not depend on parameters implicitly provided by the plugin. The profile introspection function should also be the only one providing defaults. When creating an ErasureCodeInstance via the factory, the requirement could be that all parameters need to be provided.