81 lines
2.5 KiB
Bash
Executable File
81 lines
2.5 KiB
Bash
Executable File
#!/bin/bash
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#
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# .---. . .
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# | | |
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# |--- .--. .-. .-. .-.| .-. .--.--. |.-. .-. .--. .-.
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# | | (.-' (.-' ( | ( )| | | | )( )| | (.-'
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# ' ' --' --' -' - -' ' ' -' -' -' ' - --'
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#
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# Freedom in the Cloud
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#
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# Cron functions
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#
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# License
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# =======
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#
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# Copyright (C) 2014-2016 Bob Mottram <bob@freedombone.net>
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#
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU Affero General Public License as published by
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# the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU Affero General Public License for more details.
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#
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# You should have received a copy of the GNU Affero General Public License
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# along with this program. If not, see <http://www.gnu.org/licenses/>.
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function cron_add_mins {
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if ! grep -q "${2}" /etc/crontab; then
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job_user='root'
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if [ $3 ]; then
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job_user=$3
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fi
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echo "*/${1} * * * * ${job_user} ${2}" >> /etc/crontab
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systemctl restart cron
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fi
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}
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function randomize_cron {
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# The predictable default timing of Debian cron jobs might
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# be exploitable knowledge. Avoid too much predictability
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# by randomizing the times when cron jobs run
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if [[ $(is_completed $FUNCNAME) == "1" ]]; then
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return
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fi
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# randomize the day on which the weekly cron job runs
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randdow=$(($RANDOM%6+1))
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sed -i "s|\* \* 7|* * $randdow|g" /etc/crontab
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# randomize the time when the weekly cron job runs
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randmin=$(($RANDOM%60))
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randhr=$(($RANDOM%3+1))
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sed -i "s|47 6|$randmin $randhr|g" /etc/crontab
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# randomize the time when the daily cron job runs
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randmin=$(($RANDOM%60))
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randhr=$(($RANDOM%3+4))
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sed -i "s|25 6\t\* \* \*|$randmin $randhr\t* * *|g" /etc/crontab
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# randomize the time when the hourly cron job runs
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randmin=$(($RANDOM%60))
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sed -i "s|17 \*\t|$randmin *\t|g" /etc/crontab
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# randomize monthly cron job time and day
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randmin=$(($RANDOM%60))
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randhr=$(($RANDOM%22+1))
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randdom=$(($RANDOM%27+1))
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sed -i "s|52 6\t|$randmin $randhr\t|g" /etc/crontab
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sed -i "s|\t1 \* \*|\t$randdom * *|g" /etc/crontab
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systemctl restart cron
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mark_completed $FUNCNAME
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}
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# NOTE: deliberately there is no "exit 0"
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