REQ-6: Graceful Shutdown Handling

[riz-hossain]

ZeuZ Agent

• Item: REQ-6
• Type: Requirement

Item Description

Graceful Shutdown Handling

Handle Ctrl+C interruptions and termination signals (such as SIGTERM and SIGKILL) so the node exits cleanly without hanging.

Behavior Requirements

• Capture termination signals and initiate a controlled shutdown sequence.
• Stop running tasks safely and release resources before exit.
• Ensure the process completes shutdown promptly and does not stall.

Parent Requirement

Additional Instructions

Generated by ZeuZ Agent.

In general, to fix this kind of problem you should avoid returning raw exception messages or stack traces to clients. Instead, log the full error details on the server (including stack trace if needed for debugging), and send a generic, non-sensitive message in the HTTP response. This preserves diagnostic usefulness for developers while preventing attackers from learning about internal implementation details.

For this specific case in server/mobile.py, the main change is to modify the except Exception as e: block in is_ios_app_installed so that it no longer returns str(e) to the client. Instead, it should log the exception using the existing logging module that is already imported at the top of the file, and then return a generic error message. Concretely:

• Use logging.exception(...) (or logging.error(...)) inside the except block to record the error and stack trace on the server.
• Remove str(e) from the returned JSON, replacing it with a neutral message such as "An internal error occurred while checking installation status." that does not reveal system details.
• Keep the "installed": False key so that existing client logic relying on that field continues to work; only the content of the "error" field is changed to be generic.
• All changes are confined to the is_ios_app_installed function (lines 787–808) in server/mobile.py; no new imports or external libraries are required since logging is already imported.