CNG backups, use the --no-preserve flag with s3cmd
By default the backups we run using s3cmd will try to write the files to disk using the file's attribute owner data. But the s3cmd is running as the git user, so may fail to do this in some cases. We could consider using s3cmd's
--no-preserve flag to do this.
In regular use, all of gitlab's objects should be owned by
git but this may not be true for the registry's objects. We should probably just ignore the file owner.
This recently came up in a situation with a customer, not for the registry but actually for uploads. In their case they had synced the uploads to object storage using s3cmd rather than the migration tools. (https://gitlab.com/gitlab-org/distribution/team-tasks/issues/386)