technical description

Dudki is a process monitoring daemon that sits silently in background and checks whether the processes he feels responsible for are running. He gets a process identifier from the file, sees if the process is alive and if not, does his best to start one. Dudki reports the actions taken to his owner via email.

Here is the sample dudki.conf configuration file:

  CheckInterval 60
  PidFile /var/run/dudki.pid
  Daemonize on

  Notify mailto:hostmaster@example.org
  MailtoHeader From "Dudki <dudki@example.org>"

  <Process named>
   PidFile /var/run/named.pid
   RestartCommand "exec /usr/sbin/named"
  </Process>
  <Process sshd>
   PidFile /var/run/sshd.pid
   RestartCommand "exec /usr/sbin/sshd"
  </Process>

  <Process cron>
   ProcessName cron
   RestartCommand "exec /usr/sbin/cron"
  </Process>

In this example dudki monitors the bind DNS server, ssh secure shell daemon and cron daemon, the latter is monitored by looking up the process name, not using PID-file. It checks processes every minute, restarts those that do not run and sends reports to the hostmaster@example.org email. To make even safer you can have cron return the courtesy by watching back the dudki process — make it run dudki -e command every once in a while.