pass ceph configuration to rbox-storage plugin

[jrse]

No description provided.

[jrse]

To setup a ceph connection in rbos-storage plugin
at least the following information is required:

• clustername
• username
• configuration file or environment :
  • mon host (monitor host and port)
  • keyring
  • clientId

-> this information needs to be setup in dovecot configuration files and passed to rbos-storage
-> the plugin livecycle function to read configuration needs to be evaluated.

[jrse]

• first version should support CEPH Environment variables to access ceph monitor configuration.
• poolname should be set via dovecot 10-mail.conf (mail_location: configuration)
  we will use the path setting as poolname

-- CEPH: environment variables --

The CEPH_ARGS environment variable is appended to all Ceph commands and is set so that they all use the configuration file created for tests instead of the default [/etc/ceph/ceph.conf.] link to doc

Example:
export CEPH_ARGS='--mon-host 127.0.0.1:40000'