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docs:guide-user:base-system:cron [2021/03/24 14:52] – [Task specification] vgaeteradocs:guide-user:base-system:cron [2023/08/08 11:30] – Added my cronjob to keep last N snapshots of config torxgewinde
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-====== Scheduling tasks ======+====== Scheduling tasks with cron ======
 {{section>meta:infobox:howto_links#basic_skills&noheader&nofooter&noeditbutton}} {{section>meta:infobox:howto_links#basic_skills&noheader&nofooter&noeditbutton}}
  
 ===== Introduction ===== ===== Introduction =====
-  * OpenWrt allows to run jobs (programs, scripts) at specified times using [[wp>Cron|cron]] service. +  * OpenWrt can run scheduled tasks using [[wp>Cron|cron]] service. 
-  * This how-to describes the methods for setting up cron jobs. +  * This how-to describes the method for setting up cron jobs. 
-  * See also [[docs:guide-user:advanced:watchcat|Watchcat]] to set up reboot based on schedule or connectivity.+  * See also [[docs:guide-user:advanced:watchcat|Watchcat]] to reboot based on schedule or connectivity.
  
-===== Web interface =====+===== Goals ===== 
 +  * Run programs or scripts at a specific time. 
 +  * Automate scheduled task management. 
 + 
 +===== Web interface instructions =====
 Set up cron jobs using web interface. Set up cron jobs using web interface.
   - Navigate to **LuCI -> System -> Scheduled Tasks**.   - Navigate to **LuCI -> System -> Scheduled Tasks**.
   - Edit the configuration and click the **Save** button.   - Edit the configuration and click the **Save** button.
  
-===== Command-line interface =====+===== Command-line instructions =====
 Set up cron jobs using command-line interface. Set up cron jobs using command-line interface.
  
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 This will edit the configuraion ''/etc/crontabs/root'' file in [[docs:guide-user:base-system:user.beginner.cli#editing_files|vi editor]]. This will edit the configuraion ''/etc/crontabs/root'' file in [[docs:guide-user:base-system:user.beginner.cli#editing_files|vi editor]].
  
-:!: There should be a end-of-line character on the last line of the crontab file.+:!: There should be a EOL character on the last line of the crontab file.
 Just leave an empty line at the end to be sure. Just leave an empty line at the end to be sure.
  
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 If you set the day of the week to 7, BusyBox will go bonkers and run your command every day. If you set the day of the week to 7, BusyBox will go bonkers and run your command every day.
  
-Table of shortcuts:+**Table of shortcuts:**
  
 ^ Shortcut ^ Equivalent ^ Description ^ ^ Shortcut ^ Equivalent ^ Description ^
-| ''@reboot'' | //(none)// | At system startup | 
 | ''@yearly'' | ''0 0 1 1 *'' | Every year | | ''@yearly'' | ''0 0 1 1 *'' | Every year |
 | ''@annually'' | ''0 0 1 1 *'' | Every year | | ''@annually'' | ''0 0 1 1 *'' | Every year |
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 | ''@midnight'' | ''0 0 * * *'' | Every day | | ''@midnight'' | ''0 0 * * *'' | Every day |
 | ''@hourly'' | ''0 * * * *'' | Every hour | | ''@hourly'' | ''0 * * * *'' | Every hour |
 +
 +:!:  Time shortcuts are not enabled by default. Shortcuts require compiling busybox with FEATURE_CROND_SPECIAL_TIMES enabled in the busybox compile options.
  
 ===== Troubleshooting ===== ===== Troubleshooting =====
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   * [[man>crontab(1)]], [[man>crontab(5)]]   * [[man>crontab(1)]], [[man>crontab(5)]]
   * [[https://busybox.net/downloads/BusyBox.html#crontab|BusyBox crontab]]   * [[https://busybox.net/downloads/BusyBox.html#crontab|BusyBox crontab]]
-  * [[http://adminschoice.com/crontab-quick-reference|Crontab – Quick Reference]]+  * [[http://adminschoice.com/crontab-quick-reference|Crontab quick reference]]
  
 ==== Periodic reboot ==== ==== Periodic reboot ====
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 59 05 * * 1 /usr/bin/wol -h 192.168.1.255 xx:xx:xx:xx:xx:xx 59 05 * * 1 /usr/bin/wol -h 192.168.1.255 xx:xx:xx:xx:xx:xx
 # crontab must end with the last line as space or a comment # crontab must end with the last line as space or a comment
 +</code>
 +
 +==== Keep number of configs / snapshots of config ====
 +To keep a number N of configurations/settings at the directory "/root", you can also use cron. This way you can access and restore configurations of the past 100 days. The cronjob can easily be extended to copy the config to another device, to be able to replicate a broken OpenWRT device from scratch.
 +
 +<code bash>
 +#Make a new backup/configurations snapshot at nighttime 00:01 am, keep last N=100 snapshots
 +#01 00 * * * sysupgrade -b "/root/backup-${HOSTNAME}.tar.gz" # <-- keep just one config
 +01 00 * * * find "/root" -type f -name "backup-*.tar.gz" | sort -r | awk 'NR > 100' | xargs rm -f; sysupgrade -b "/root/backup-${HOSTNAME}-$(date +\%Y-\%m-\%d-\%H-\%M-\%S).tar.gz"
 </code> </code>
  
  • Last modified: 2023/10/14 06:55
  • by vgaetera