systemd-exit-codes.md

If you've written service files for systemd you've probably experienced that some applications return unexpected (non-zero) exit codes, even when terminating successfully. I had to deal with this when I wrote the service file for this blog which is running on Node.js.

SIGTERM and SIGINT have default handlers on non-Windows platforms that resets the terminal mode before exiting with code 128 + signal number. If one of these signals has a listener installed, its default behaviour will be removed (node will no longer exit).

By default, when killed with SIGTERM, Node.js exits with the status code 143. That is 128 + SIGTERM. This is expected behavior but it causes the following annoying error message in the system journal.

Unit example.service entered failed state.

The solution is to explicitly define the expected exit code in the service file with the SuccessExitStatus option under the [Service] section.

[Service]
SuccessExitStatus=143

Sources

• Node.js v5.2.0 Documentation
• Sylvain Leroux on StackOverflow