NIFI-11327 Add Export/Import All - NiFi CLI - NiFi Registry

[timeabarna]

Summary

Have a command registry export-all-flows that does the following:
List all the buckets, for each bucket, list all flows, for each flow, list all versions and export each version. All files should be landing in a target directory provided as an argument of the function.

Have a command registry import-all-flows that does the following:
It takes a directory as input (the one created by the export-all-flows command), and goes through the files to create the corresponding buckets, flows and flows versions.
The original author, bucket id and flow id need to be kept.

Use cases:
use case 1: NiFi 1 -> connecting to NiFi Registry 1, "re-initialising" an existing NiFi Registry, the NiFi Registry does not change, only its configuration.
export everything
change the NR flow definition repo backend from local FS to database (for example), or from git to database, etc
import everything
the existing NiFi instance should not see any change
use case 2: NiFi 1 -> Registry 1, NiFi 2 -> Registry 2, Disaster Recovery kind of thing between two different sites.
export everything from NR1
import everything into NR2
If the import into NR2 is adding new versions, then NiFi 2 should be able to update an existing PG to a newer version of the flow.

NIFI-11327

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  • JDK 11
  • JDK 17

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[timeabarna]

Hello @bbende,

Can you please review this PR?

Thanks in advance.

[exceptionfactory]

Thanks for working on this feature @timeabarna. I noted several general questions regarding the naming of the new REST Resource and potential concerns related to reading everything into memory. See the individual comments for details.

[timeabarna]

Hello @bbende and @exceptionfactory,

Thanks you very much for your review. I've updated the code based on your recommendations, improved serialisation and added storage location update.

Can you please check again?

Thanks in advance.

[timeabarna]

Thanks @bbende and @exceptionfactory for your help, I've updated the PR.

[bbende]

Latest updates look good, this is very close.

[bbende]

Thanks for all the updates, this looks good to me. Everything is working as described, going to merge.