Cluster Operation Backups to S3 fail with NullPointerException

Issue

Cluster Operations Backup build fails for controller(s) with a NullPointerException similar to:

Uploading...
java.lang.NullPointerException
    at com.infradna.hudson.plugins.backup.store.S3Store.getClient(S3Store.java:133)

Environment

CloudBees CI (CloudBees Core) on modern cloud platforms - Operations Center
CloudBees CI (CloudBees Core) on traditional platforms - Operations Center
CloudBees Jenkins Enterprise - Operations center
CloudBees Backup Plugin >= 3.38.33 and < 3.38.35

Related Issue(s)

BEE-3409: Error when running a backup cluster operation to S3 storage

Resolution

The recommended solution is to upgrade CloudBees CI Operations Center and Controllers to version 2.289.1.2 or later.

Workaround

A workaround is to upgrade the CloudBees Backup Plugin to version 3.38.35, at least on the Controllers.

Our experience is that always the same controller is impacted by this issue. So another workaround would be to configure the Cluster Operations with a failure mode "Fail At The End" in the "Advanced Operation Options" so that backup operations of most controllers are not interrupted and succeed. Then create another Cluster Operations Backup job for the impacted controller only.

References

[Backup and restore on AWS

CloudBees Docs](https://docs.cloudbees.com/docs/cloudbees-ci/latest/backup-restore/aws#_backup_to_s3_with_amazon_s3_compatible_storage_systems)
[Using the CloudBees Backup plugin

CloudBees Docs](https://docs.cloudbees.com/docs/cloudbees-ci/latest/backup-restore/cloudbees-backup-plugin)