Create a gist now

Instantly share code, notes, and snippets.

Elastic Beanstalk worker with graceful shutdown
files:
/usr/local/bin/worker:
mode: "000755"
owner: root
group: root
content: |
#!/bin/sh
restartLimit=10
timeLimit=300 # 5 minutes
crashCount=0
cd /var/app/current/
while true; do
node services/queue/worker.js &
pid=$!
echo $pid > /tmp/worker.pid
wait $pid
retval=$?
if [ $retval -eq 0 ]; then
exit 0
else
# Crash
crashTime=`date +%s`
if [ -z "$firstCrashTime" ]; then
firstCrashTime=$crashTime
fi
timeDiff="$[$crashTime - $firstCrashTime]"
if [ $timeDiff -lt $timeLimit ]; then
crashCount=$[$crashCount + 1]
if [ $crashCount -gt $restartLimit ]; then
echo "Too many crashes, worker stopped"
exit $retval
fi
else
crashCount=1
firstCrashTime=$crashTime
fi
echo "Worker crashed, restarting"
fi
done
/etc/init.d/worker:
mode: "000755"
owner: root
group: root
content: |
#!/bin/sh
#
# worker - stops and starts the worker
#
# chkconfig: - 20 80
# description: Worker with graceful shutdown
# Source function library.
. /etc/rc.d/init.d/functions
exec="/usr/local/bin/worker"
prog="worker"
env="/tmp/env"
log="/var/log/nodejs/nodejs.log"
[ -e /etc/sysconfig/$prog ] && . /etc/sysconfig/$prog
lockfile=/var/lock/subsys/$prog
pidfile=/tmp/${prog}.pid
min_kill_timeout=5
default_kill_timeout=60
start() {
echo -n "Starting $prog:"
. $env
daemon --user=games $exec >> $log 2>&1 &
retval=$?
echo
pid=`cat $pidfile`
[ $retval -eq 0 ] && touch $lockfile && echo "[Started $pid]"
return $retval
}
stop() {
kill_timeout=$default_kill_timeout
if [ -f $env ]; then
. $env
if [ -n "$WORKER_SHUTDOWN_DELAY" ] && [ "$WORKER_SHUTDOWN_DELAY" -gt $min_kill_timeout ]; then
kill_timeout="$WORKER_SHUTDOWN_DELAY"
fi
fi
pid=`cat $pidfile`
i="0"
echo "Stopping $prog [$pid]:"
kill $pid
retval=$?
while [ $i -lt $kill_timeout ]; do
if [ -d "/proc/$pid" ]; then
sleep 1
i=$[$i+1]
else
rm -f $lockfile
[ $retval -eq 0 ] && echo "[Stopped]"
return $retval
fi
done
echo "$prog did not shut down in the grace period, sending sigkill"
pkill -9 $prog
retval=$?
rm -f $lockfile
[ $retval -eq 0 ] && echo "[Stopped]"
return $retval
}
restart() {
stop
start
}
reload() {
restart
}
force_reload() {
restart
}
rh_status() {
if [ -f $lockfile ]; then
echo "$prog is running!"
return 0
else
echo "$prog is not running!"
return 1
fi
}
rh_status_q() {
rh_status >/dev/null 2>&1
}
case "$1" in
start)
rh_status_q && exit 0
$1
;;
stop)
rh_status_q || exit 0
$1
;;
restart)
$1
;;
reload)
rh_status_q || exit 7
$1
;;
force-reload)
force_reload
;;
status)
rh_status
;;
condrestart|try-restart)
rh_status_q || exit 0
restart
;;
*)
echo $"Usage: $0 {start|stop|status|restart|condrestart|try-restart|reload|force-reload}"
exit 2
esac
exit $?
/opt/elasticbeanstalk/hooks/appdeploy/post/60-gen-env.sh:
mode: "000755"
owner: root
group: root
content: |
#!/bin/bash
NODE_INSTALL_DIR="$(/opt/elasticbeanstalk/bin/get-config container -k nodejs_install_dir)"
NODE_VERSION="$(/opt/elasticbeanstalk/bin/get-config optionsettings -n "aws:elasticbeanstalk:container:nodejs" -o "NodeVersion")"
export NODE_PATH="${NODE_INSTALL_DIR}/node-v${NODE_VERSION}-linux-x64"
export PATH="$NODE_PATH/bin:$PATH"
ENVIRONMENT_CONFIG="$(/opt/elasticbeanstalk/bin/get-config environment)"
ENV_VARS=`echo ${ENVIRONMENT_CONFIG} | sed 's/"\([^"]*\)":"\([^"]*\)",*/\1="\2" /g;s/^{//;s/}$//'`
echo "export $ENV_VARS PATH=\"$PATH\"" > /tmp/env
/opt/elasticbeanstalk/hooks/appdeploy/post/70-restart-worker.sh:
mode: "000755"
owner: root
group: root
content: |
#!/bin/bash
/etc/init.d/worker stop
. /tmp/env
if [ "$NODE_TYPE" != "api" ]; then
# Start the worker when not a pure API node
/etc/init.d/worker start
fi
/opt/elasticbeanstalk/hooks/configdeploy/post/80-gen-env.sh:
mode: "120755"
owner: root
group: root
content: "/opt/elasticbeanstalk/hooks/appdeploy/post/60-gen-env.sh"
/opt/elasticbeanstalk/hooks/configdeploy/post/90-restart-worker.sh:
mode: "120755"
owner: root
group: root
content: "/opt/elasticbeanstalk/hooks/appdeploy/post/70-restart-worker.sh"
/opt/elasticbeanstalk/hooks/restartappserver/post/80-gen-env.sh:
mode: "120755"
owner: root
group: root
content: "/opt/elasticbeanstalk/hooks/appdeploy/post/60-gen-env.sh"
/opt/elasticbeanstalk/hooks/restartappserver/post/90-restart-worker.sh:
mode: "120755"
owner: root
group: root
content: "/opt/elasticbeanstalk/hooks/appdeploy/post/70-restart-worker.sh"
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment