FALLBACK

Command line tools for checking the availability and response time of any service running on TCP, with sending a mail notification when changing status.

THE BEER-WARE LICENSE:

This project is licensed under the "THE BEER-WARE LICENSE": As long as you retain this notice you can do whatever you want with this stuff. If we meet some day, and you think this stuff is worth it, you can buy me a beer in return.

Command line options:

      --help         Show this message
 -h   --host         Ip-address or domain name (required)
 -p   --port         Port number (optional, default: 80)
 -t   --timeout      Maximum response time (optional, default: 20, seconds)
 -s   --sleep        Sleep time after a successful check (optional, default: 1, seconds)
 -c   --count        Stop after count of connection attempts (optional, default: 0, operate until interrupted). 
 -m   --mail         Notification email or emails separated pattern /[\s,;|]+/ (optional)

Basic usage:

# php fallback.php --host=example.com -c=100
  Sat, 31 Mar 18 11:19:27 +0000 FALLBACK: Process has died! restarting...
  Sat, 31 Mar 18 11:19:27 +0000 FALLBACK: example.com:80 - OK (time: 0.192442 sec.)
  Sat, 31 Mar 18 11:19:29 +0000 FALLBACK: example.com:80 - OK (time: 0.186559 sec.)
  Sat, 31 Mar 18 11:19:30 +0000 FALLBACK: example.com:80 - OK (time: 0.220498 sec.)
  Sat, 31 Mar 18 11:19:32 +0000 FALLBACK: example.com:80 - OK (time: 1.321489 sec.)
  Sat, 31 Mar 18 11:19:33 +0000 FALLBACK: example.com:80 - OK (time: 0.194539 sec.)
  Sat, 31 Mar 18 11:19:35 +0000 FALLBACK: example.com:80 - OK (time: 0.183689 sec.)
  Sat, 31 Mar 18 11:19:36 +0000 FALLBACK: example.com:80 - OK (time: 0.186502 sec.)
  ^CSat, 31 Mar 18 11:19:36 +0000 FALLBACK: got signal 2 and will exit.
  Sat, 31 Mar 18 11:19:36 +0000 FALLBACK: example.com:80 STATISTICS: 7 total, 7 responses, 0 (0%) timeouts, response time min/avg/max 0.183689/0.355103/1.321489 sec.

Or so...

/etc/crontab

# Fallback - provide start-up (and restart the script in case of death)
*/2     *       *       *       *       root            cd /path/to && php fallback.php --host='www.example.com' --timeout=30 --sleep=5 --count=3600 --mail='user1@example.com user2@example.com userN@example.com' >> /var/log/fallback.log

/etc/newsyslog.conf

# Fallback - rotation of the log file
/var/log/fallback.log 		    root:wheel      644  10    1024  *     JC