[SPARK-27626] Fix `docker-image-tool.sh` to be robust in non-bash shell env

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0
• Fix Version/s: 2.3.4, 2.4.4, 3.0.0
• Component/s: Kubernetes, Spark Core
• Assignee: Dongjoon Hyun
• Reporter: Dongjoon Hyun
• Created: 02/May/19 21:47
• Updated: 17/May/20 18:25
• Resolved: 03/May/19 17:17

Issue Links

• links to: GitHub Pull Request #24517