+++ /dev/null
-#!/bin/bash
-#
-# Generic respawner for daemon processes.
-#
-# Created: Fri, 16 Apr 2004 17:40:36 +0200 zacchiro
-# Last-Modified: Fri, 16 Apr 2004 17:40:36 +0200 zacchiro
-#
-# by --Zack <zack@cs.unibo.it>
-#
-# Test to see if a daemon process (run via /etc/init.d/script) if still alive,
-# if not it respawns it using the corresponding init script. In order to check
-# if the daemon is still alive different predicates could be used:
-# 1) "ps" check with its pid
-# 2) http request to its url (if it's a web services)
-# all the available predicated can be enable or not (command line choice), all
-# the enabled predicates are ANDed. It's enough that one of them fails to
-# trigger daemon respawning.
-#
-# This respawner is supposed to be executed by "start" target of daemon's init.d
-# script.
-#
-# Sample /etc/init.d/foo script:
-#
-# DAEMON="/usr/sbin/foo"
-# PIDFILE="/var/run/$DAEMON.pid"
-# start)
-# echo -n "Starting $DAEMON"
-# start-stop-daemon \
-# --start --background --pidfile $PIDFILE --make-pidfile --exec $DAEMON
-# echo "."
-# echo -n "Starting $DAEMON respawner"
-# /etc/init.d/daemon_respawner.sh -p $PIDFILE \ -m root@localhost \
-# -r http://localhost:9999/help -d `basename $0` &
-# echo "."
-# ;;
-# stop)
-# echo -n "Stopping $DAEMON respawner"
-# /etc/init.d/daemon_respawner.sh -d `basename $0` -s
-# echo "."
-# echo -n "Stopping $DAEMON"
-# start-stop-daemon --stop --pidfile $PIDFILE
-# rm -f $PIDFILE
-# echo "."
-# ;;
-# ...
-#
-
-# parse arguments
-TEMP=`getopt -o p:r:d:i:m:s --long pidfile:request:daemon:interval:mailto:stop -- "$@"`
-if [ $? != 0 ]; then
- echo "Usage: ./daemon_respawner [-p|--pidfile <pidfile>] [-r|--request <url>] [-i|--interval <interval>] [-m|--mailto <mail>] -d|--daemon <daemon>"
- echo " ./daemon_respawner -d|--daemon <daemon> -s|--stop"
- exit 1
-fi
-PIDFILE=""
-REQUEST=""
-DAEMON=""
-INTERVAL="60"
-MAILTO=""
-STOP=""
-eval set -- "$TEMP"
-while true ; do
- case "$1" in
- -p|--pidfile) PIDFILE="$2"; shift 2 ;;
- -r|--request) REQUEST="$2"; shift 2 ;;
- -d|--daemon) DAEMON="$2"; shift 2 ;;
- -i|--interval) INTERVAL="$2"; shift 2 ;;
- -m|--mailto) MAILTO="$2"; shift 2 ;;
- -s|--stop) STOP="yes"; shift ;;
- --) shift; break ;;
- esac
-done
-if [ -z "$DAEMON" ]; then
- echo "No daemon provided: aborting."
- exit 2
-fi
-MYPIDFILE="/var/run/$DAEMON""_respawner.pid"
-if ! [ -z "$STOP" ]; then # stop an active respawner and exit
- if [ -r "$MYPIDFILE" ]; then
- kill `cat "$MYPIDFILE"`
- fi
- rm -f "$MYPIDFILE"
- exit 0
-fi
-if [ -z "$PIDFILE" -a -z "$REQUEST" ]; then
- echo "Neither pidfile nor request URL was provided: aborting."
- exit 2
-fi
-
-TIMEOUT="5" # timeout for http requests
-
-# usage: alert <subject> <body>
-alert ()
-{
- if [ -z "$MAILTO" ]; then
- echo "ALERT: $1"
- echo "ALERT: $2"
- echo
- else
- echo "$2" | mail -s "$1" $MAILTO
- fi
-}
-
-# check if daemon is still alive
-daemon_is_alive ()
-{
- IS_DEAD=""
- if ! [ -z "$PIDFILE" ]; then # pid check enabled
- if ! (ps `cat $PIDFILE` &> /dev/null); then # pid is no longer alive
- IS_DEAD="true"
- fi
- fi
- if ! [ -z "$REQUEST" ]; then # request check enabled
- if ! (wget -T $TIMEOUT -O /dev/null "$REQUEST" &> /dev/null); then
- # no answer
- IS_DEAD="true"
- fi
- fi
- test -z "$IS_DEAD"
-}
-
-# respawn daemon
-start_daemon ()
-{
- rm -f "$MYPIDFILE"
- invoke-rc.d $DAEMON stop
- invoke-rc.d $DAEMON start &
- exit 0 # the respawner will be restarted by daemon's init.d script
-}
-
-# first check
-sleep 1
-if ! daemon_is_alive; then
- alert "$DAEMON failed to start :-((" "$DAEMON died during initialization :-((, enjoy debugging! :-P. Cheers."
- exit 3
-fi
-# save pid
-echo $$ > "$MYPIDFILE"
-# continuous checks
-while true; do
- sleep $INTERVAL
- if ! daemon_is_alive; then
- alert "$DAEMON died :-(, restarting it ..." "$DAEMON died miserably :-(. I'm going to try restarting it, you will receive an additional mail in case of failure. Cheers."
- start_daemon # performed in background
- fi
-done
-
projects / helm.git / blobdiff