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Bucket Owners

1. Overview​

Every bucket in Ozone has an owner property that identifies the user who owns the bucket. A bucket has a single owner. The bucket owner plays a role in access control and property management, particularly when using Ozone's native ACL authorization.

2. Setting the Bucket Owner​

During Bucket Creation​

When creating a bucket, the owner can be explicitly specified using the --user or -u command-line option:

ozone sh bucket create /myvolume/mybucket --user alice

If the owner is not specified during creation, the owner defaults based on the authentication method:

  • S3 Authentication: Owner defaults to the short username derived from the S3 access ID.
  • Standard Authentication: Owner defaults to the current user's short username (UserGroupInformation.getCurrentUser().getShortUserName()).

Example:

# Create bucket without specifying owner (defaults to current user)
$ ozone sh bucket create /myvol1/buck1
$ ozone sh bucket info /myvol1/buck1
{
  "volumeName" : "myvol1",
  "name" : "buck1",
  "owner" : "om",
  ...
}

Changing Bucket Ownership​

The bucket owner can be changed after creation using the bucket update command:

ozone sh bucket update <volume>/<bucket> --user <new_owner>

Or using the short form:

ozone sh bucket update <volume>/<bucket> -u <new_owner>

Example:

$ ozone sh bucket update /myvol1/buck1 --user bob
{
  "volumeName" : "myvol1",
  "name" : "buck1",
  "owner" : "bob",
  "modificationTime" : "2026-01-25T16:06:38.516Z",
  ...
}

Requirements for Changing Ownership:

  • Permissions: When Ozone ACL is enabled, the user attempting to change ownership must have WRITE_ACL permission on the bucket. This ensures that only authorized users can transfer ownership.

Owner vs. ACLs:

Changing the bucket owner via ozone sh bucket update -u <new_owner> updates the ownership metadata but does not automatically modify ACLs. The previous owner's ACL entries remain unchanged. If you need to revoke the old owner's access entirely, you must manage ACLs separately using ACL update commands.

3. Bucket Owner Privileges​

Property Updates​

When using Ozone's native ACL authorization, the bucket owner can update bucket properties. Bucket properties include:

  • Storage type
  • Versioning
  • Encryption settings
  • Quotas (space and namespace)
  • Bucket layout
  • Other bucket metadata

Access Control Check:

For native ACL authorization, bucket property updates are allowed by:

  • Administrators
  • Bucket owners

For Ranger authorization, bucket property updates are determined by Ranger policies.

4. Volume Owner vs. Bucket Owner​

Volume Owner Privileges:

The volume owner has broader privileges than the bucket owner:

  • Volume owners bypass ACL checks for all resources (buckets, keys, prefixes) within their volume.
  • Volume owners have implicit access to all buckets in their volume, regardless of bucket ownership or ACLs.

Bucket Owner Privileges:

Bucket owners have limited privileges:

  • Bucket owners can update bucket properties (when using native ACL authorization).
  • Bucket owners do not bypass ACL checks for keys or prefixes within the bucket.
  • Bucket ownership is primarily used for property management, not access control bypass.
note

Volume ownership takes precedence over bucket ownership in access control decisions. If a user is the volume owner, they have full access regardless of bucket ownership.