Make Trunk-Recorder logrotate friendly, via syslogFriendly bool config option.

[Dygear]

More testing is required for a few days before this is merged in, I want to make sure it works as intended before pulled.

Added a syslogFriendly config option, that by default is false. When set to true creates a trunk-recorder.log file that can be rotated with logrotate. Logrotate sends a SIGHUP signal that is handled by this change. Closes #833.

Implementation Summary

Changes Made:

1. trunk-recorder/global_structs.h:39 - Added bool syslog_friendly field to the Config struct

2. trunk-recorder/config.cc:

   • Added global log sink variable for SIGHUP handler access
   • Modified setup_file_log() to accept syslog_friendly parameter
   • When syslog_friendly is true, uses static filename trunk-recorder.log instead of timestamped %m-%d-%Y_%H%M_%2N.log
   • When syslog_friendly is true, disables automatic rotation (no rotation_size or time_based_rotation)
   • Added config reading for syslogFriendly option (defaults to false)
   • Added logging output to show the mode status

3. trunk-recorder/monitor_systems.cc:

   • Added SIGHUP signal handler (rotate_log_signal)
   • Added flag rotate_log_flag to safely handle signal in main loop
   • Implemented log rotation logic that flushes and reopens the log file when SIGHUP is received
   • Logs rotation events for debugging

How to Use:

Add this to your config.json:

{
  "logFile": true,
  "logDir": "logs",
  "syslogFriendly": true,
  ...
}

Example logrotate Configuration:

Create /etc/logrotate.d/trunk-recorder:

/path/to/logs/trunk-recorder.log {
    daily
    rotate 7
    compress
    delaycompress
    missingok
    notifempty
    postrotate
        killall -SIGHUP trunk-recorder
    endscript
}

Behavior:

• Default (syslogFriendly: false): Uses timestamped log files with automatic rotation at 100MB or daily
• Syslog-friendly mode (syslogFriendly: true):
  • Uses static filename trunk-recorder.log
  • No automatic rotation by Trunk-Recorder
  • Responds to SIGHUP signal for external rotation (logrotate)
  • Logs rotation events for monitoring

[robotastic]

This makes sense to me - can you add an entry to the Config doc: https://github.com/TrunkRecorder/trunk-recorder/blob/master/docs/CONFIGURE.md