[IMPALA-12397] NullPointerException in SHOW ROLES when there are no roles

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: Impala 4.4.0
• Component/s: Security
• Labels: newbie ramp-up
• Epic Color: ghx-label-9
• Assignee: ji.chen
• Reporter: Quanlong Huang
• Created: 23/Aug/23 04:54
• Updated: 26/Mar/24 04:44
• Resolved: 26/Mar/24 04:44

Description

When there are no roles in Ranger, SHOW ROLES statement hits NullPointerException:

Query: show roles
ERROR: InternalException: Error executing SHOW ROLES. Ranger error message: null

The cause is 'roles' here is null:

Set<RangerRole> roles = plugin_.get().getRoles().getRangerRoles();
roleNames = roles.stream().map(RangerRole::getName).collect(Collectors.toSet());

https://github.com/apache/impala/blob/08501cef2df16991bbd99656c696b978f08aeebe/fe/src/main/java/org/apache/impala/authorization/ranger/RangerImpaladAuthorizationManager.java#L135-L136

To reproduce this, start Impala cluster with Ranger authorization:

bin/start-impala-cluster.py --impalad_args="--server-name=server1 --ranger_service_type=hive --ranger_app_id=impala --authorization_provider=ranger" --catalogd_args="--server-name=server1 --ranger_service_type=hive --ranger_app_id=impala --authorization_provider=ranger"

At the begining, there are no roles in Ranger. Run "SHOW ROLES" in Impala to reproduce the error.