5.7. Logging configuration changes The syslog-ng Premium Edition 7 Administrator Guide
Every time syslog-ng is started, or its configuration is reloaded, it automatically logs the SHA-1 fingerprint of its configuration file using the
internal() message source. That way any modification of the configuration of your syslog-ng clients is visible in the central logs. Note that the log message does not contain the exact change, nor can the configuration file be retrieved from the fingerprint. Only the fact of the configuration change can be detected.
Modular configuration files that are included in the main configuration file of syslog-ng PE are included when the fingerprint is calculated. However, other external files (for example, scripts used in program sources or destinations) are excluded, therefore their modifications do not change the fingerprint.
The fingerprint can be examined with the logchksign command-line application, which detects that the fingerprint was indeed generated by a syslog-ng application. Just paste the hashes from the log message after the logchksign command like in the following example:
bin/logchksign "cfg-fingerprint='832ef664ff79df8afc66cd955c0c8aaa3c343f31', cfg-nonce-ndx='0', cfg-signature='785223cfa19ad52b855550be141b00306347b0a9'"