Nova-compute generates incorrect exit code in case if child spawning failed

[Margarita Shakhova]

In situation if nova-compute main process fails to spawn a child (worker) process e.g. because of database connection failure: ERROR oslo_db.sqlalchemy.engines DBConnectionError: (pymysql.err.OperationalError) worker process exits with code 1, however, exit code of main process is 0. It shold be 1 because the service failed to start because of error.

[Matt Riedemann (mriedem)]

This is likely something that is controlled down in the oslo.service library code which nova-compute uses.