Description:

The get_user_if_exists function lacks visibility into authentication failures. We can't debug why "user already exists" errors happen in devstack but not in stage.

Solution:

• Added comprehensive debugging with new toggle IGNORE_LOGGED_IN_USER_ON_MISMATCH.

• Added custom attributes to track authentication flow and detect issues:

      - Username mismatches between details and existing users.
      - User lookup success/failure states.
      - Database errors during user retrieval.
  

• Improved logging with detailed info and warning messages.

• Removed unnecessary pass statement for cleaner code.

JIRA Ticket:

BOMS-3

Reference PR:

PR

Reference pr for testing legacy get_user_if_exists code with current test_file:

#395