Shuts down idle jenkins instances

build_step.sh

#
# This script shuts down my AWS EC2 hosted Jenkins if
# there were no builds in the last hour.
#
# Set this script to run as build step in jenkins every minute like this
#
#  [x] Build periodically
#
#  Schedule   * * * * *
#
# There will be only one build job at a time that is constantly restarted if
# there is activity, and shuts down if there is none.
#
# To allow the user running the jenkins server to shut down the instance,
# fire up `visudo` and add this line:
#
#   jenkins   ALL=NOPASSWD: /sbin/shutdown
#

RUN_FREQUENCY=3600 # in seconds

sleep $(($RUN_FREQUENCY - 100))

LAST_BUILD=`curl --silent http://localhost:8080/rssAll|tr '>' '\n'|grep /updated|head -n 1|tr 'TZ</updated' ' '`

test $((`date -u +%s` - `date -u -d"$LAST_BUILD" +%s`)) -lt $(($RUN_FREQUENCY - 100)) || sudo shutdown -h +1

screenshot.png