Exclude folders for backing up

[wzrdtales]

See #1430

The team has discussed and we're not planning to support individual file/directory backup or exclusion, so closing this issue.

Well the team made a weird decision. Excluding folders is such a basic operation done in absolutely any setup backing up data. The simplest reason would be: No one wants to backup the cache directory with millions of small files. Those will be anyways regenerated.

[reasonerjt]

We will integrate with kopia and make enhancement to the FS based B/R in a future release.

I'm putting this into backlog, and we'll work on this in a future release.

[sseago]

Should we consider implementing this now that Kopia is the default?

[sseago]

Added the 1.13 candidate tag for discussion.

[draghuram]

I believe this works even today for Kopia as long as correctly formatted .kopiaignore is present in a directory. If it is present in the top level directory, it would apply to entire PV.

[sseago]

@draghuram So I guess the question would be do we need/want to build support in velero for managing .kopiaignore files based on a backup-level exclude list, or should we just point users at kopia docs and have them manage it themselves.