backup-utility: skipping db and repositories will result in errors from tar

Summary

Seen in the team demo on 2020-07-30,

backup-utility --skip db --skip repositories can result in an error from tar, because /srv/gitlab/tmp/backups will not exist. We're indirectly reliant on one of the rake tasks for db or repositories to actually create this directory.

• This would be solved by this process actually being in the Rails / Rake codebase. (#1127)
• We should implement a confirmed creation of the destination, until such time as this functionality is included.

Steps to reproduce

backup-utility --skip repositories --skip db --skip registry --skip external_diffs --skip terraform_state --skip uploads

Current behavior

Dumping lfs ...
[Error] tar (child): /srv/gitlab/tmp/backups/lfs.tar.gz: Cannot open: No such file or directory
tar (child): Error is not recoverable: exiting now
tar: /srv/gitlab/tmp/backups/lfs.tar.gz: Cannot write: Broken pipe
tar: Child returned status 2
tar: Error is not recoverable: exiting now

Restore lfs failed

Expected behavior

Success

Versions

• Chart: master