[YARN-9129] Ensure flush after printing to log plus additional cleanup

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.3.0
• Assignee: Eric Yang
• Reporter: Billie Rinaldi
• Created: 14/Dec/18 21:10
• Updated: 20/Dec/18 01:48
• Resolved: 20/Dec/18 00:48

Description

Following up on findings in YARN-8962, I noticed the following issues in container-executor and main.c:

• There seem to be some vars that are not cleaned up in container_executor:
  In run_docker else: free docker_binary
  In exec_container:
  before return INVALID_COMMAND_FILE: free docker_binary
  3x return DOCKER_EXEC_FAILED: set exit code and goto cleanup instead
  cleanup needed before exit calls?
• In YARN-8777 we added several fprintf(stderr calls, but the convention in container-executor.c appears to be fprintf(ERRORFILE followed by fflush(ERRORFILE).
• There are leaks in TestDockerUtil_test_add_ports_mapping_to_command_Test.
• There are additional places where flush is not performed after writing to stderr, including main.c display_feature_disabled_message. This can result in the client not receiving the error message if the connection is closed too quickly.