Support for upgrading a cstor volume or a pool.

[vharsh]

Add support for new commands for upgrading cstor volume and pools like:

• openebs upgrade pool [--cas-type=cstor] [<pool-name(s)>] that will perform the following:

  • Check if the pool is running a version older than the cstor operator version
  • If yes and then check if there is already an upgrade job in progress. If yes, the show the status of the upgrade process.
  • If pool can be upgrade, and upgrade is not in progress, then launch the pool upgrade jobs - as outlined in https://github.com/openebs/upgrade/blob/master/docs/upgrade.md
  • show the status of the upgrade. the command can be exited with user can come back and run the same command to check the status.

• openebs upgrade volume [--cas-type=cstor] [<volume-name(s)>] that will perform the following:

  • Similar to the above with an additional check that volume can be upgraded only if the pools are already upgraded.
  • If cas-type=cstor is specified, get list of all cstor volumes and launch the Upgrade Jobs for the volumes that need to be upgraded. The upgrade job yaml format is at: https://github.com/openebs/upgrade/blob/master/docs/upgrade.md