Machine-readable restore status

[brownleej]

We have a --json flag for getting machine-readable status for a backup. When we're getting restore status from fdbrestore, we don't have this option. A JSON option would be helpful when we are working with restores from the Kubernetes operator or from other tooling, so that we could programmatically check whether the restore has completed.

[xumengpanda]

Another choice is to exposing the restore status to the special key space, which allows programmers to get partial status without pulling all status info.

[matiascognite]

Would it be possible to add some restore status data to fdbcli status json?

[OIanchevskyi]

up