Add support for additionalCommandArgs and configurable secretKey fields in barmanObjectStore. (fixes #653)

[austinmarten1]

• Add accessKeyIdField and secretAccessKeyField to backups.secret for custom S3 credential key fields

• Add additionalCommandArgs support for both wal and data sections in barmanObjectStore

  Fixes #653

[patstevens4]

+1

[ncwade]

+1

[austinmarten1]

Please note that if custom S3 credential key fields are set and a user passes S3 creds directly in the values (such as backups.s3.accessKey and backups.s3.secretKey), the generated secret will still use the hardcoded ACCESS_KEY_ID and ACCESS_SECRET_KEY strings, causing a mismatch in the barman storage config. The same applies to the recovery S3 secret.

Additionally, this change doesn't impact the barman config when recovery is configured in the chart. You would need to add the same fields from .Values.backups.secret to .Values.recovery.secret. (I guess recovery is technically out of scope here, but this would also greatly help my use case 😃)

Helps my use case as well! I can add it in here.

[austinmarten1]

Looks good, small nitpick about formatting.

Done