Support for restic

[cortopy]

When using this plugin and the restic integration, velero can't complete the backup and emits this error:

time="2021-08-06T19:51:46Z" level=error msg="Error backing up item" backup=velero/postgres-test error="restic repository is not ready: restic repository prefix (resticRepoPrefix) not specified in backup storage location's config" error.file="/go/src/github.com/vmware-tanzu/velero/pkg/restic/repository_ensurer.go:144" error.function="github.com/vmware-tanzu/velero/pkg/restic.(*repositoryEnsurer).EnsureRepo" logSource="pkg/backup/backup.go:431" name=postgres-test-86756dfc79-mhtp7

When trying to configure the plugin with I get this error

time="2021-08-06T19:56:01Z" level=error msg="Error getting backup store for this location" backupLocation=default controller=backup-sync error="rpc error: code = Unknown desc = config has invalid keys [resticRepoPrefix]; valid keys are [accessGrant bucket prefix caCert]" error.file="/go/pkg/mod/github.com/vmware-tanzu/velero@v1.4.0/pkg/plugin/framework/validation.go:50" error.function=github.com/vmware-tanzu/velero/pkg/plugin/framework.validateConfigKeys logSource="pkg/controller/backup_sync_controller.go:175"

As per this issue, it seems to me that the storj plugin has to allow resticRepoPrefix in the configuration

[iglesiasbrandon]

Hey, @cortopy thank you for bringing this up to our attention. This is not something in our current focus or short-term roadmap but we are looking for outside contributions to fix bugs like these. Let us know if you are interested in contributing!