Logging

By default, alnitak will log information to the file /var/log/alnitak.log (which can be changed via the --log flag).

The level of detail to log can be changed with the --log-level flag, which can be given the following inputs:

• no: do not log anything to the log file.
• normal: minimal logging (this is the default).
• verbose: more detailed logging.
• debug: log even more detail.

Note

At debug level, the log file may capture sensitive information. Alnitak mitigates this by redacting login keys from the log messages, and by restricting permissions of the log file when it is created. Alnitak will not change the permissions of the log file if it already exists.

The following combination of flags provide a guide as to how the program will print errors and information, and where to. You will likely only ever need a few of these scenarios, but they are all listed for the sake of completion.

Logging outcomes

flags	errors	info
	logfile, stderr	logfile
-l-	stderr	stdout
-lno	stderr
-q	logfile	logfile
-l- -q
-lno -q
-Lno	logfile, stderr
-l- -Lno	stderr
-lno -Lno	stderr
-q -Lno	logfile
-l- -q -Lno
-lno -q -Lno

As a general rule of thumb: by default, all messages (info or errors) are written to the logfile, with the error messages also written to stderr. If you want to write to stdout rather than to the logfile, then pass the -l- (--log=stdout) flag. If you want to only ever write to the logfile, then pass the -q flag. If you only want to see error messages (i.e., suppress all info output), then pass the -Lno flag.