Question
Can I Configure Cron through UCR Variables?
Answer
You want to run a command at a specific time, let’s say a backup script should be executed daily at 5am.
/root/backup.sh "%Domain Users" to backup all home directories of users belonging to the given group.
Use the following steps to create such an entry for cron.
Step 1
Decide for a name for the task (here: “backup”) and set the command to be used.
Note: In case you need some special characters (like %) they have to be “escaped” by a backslash ("\").
ucr set cron/backup/command="/root/backup.sh \"\%Domain Users\""
Step 2
Add a description for the task for improved readability.
ucr set cron/backup/description="Backup Domain Users"
Step 3
Set the user who should run the command (usually root):
ucr set cron/backup/user=root
Step 4
Define the times when the command has to be started. Syntax is the same as for a default crontab entry. As example:
| Minute | Hour | Day of Month | Month | Day of Week |
|---|---|---|---|---|
| 3 | * | */2 | 1-6 | 0,6 |
The above example would be executed at three (3) minutes after every hour (*) on the even days of the month (*/2) in January to June (1-6) when these days are Sunday (0) or Saturday (6).
A matching time would be 7:03am on Sunday, 6th of March. It would not be started on 8:03pm on Monday, 4th of May.
To set the schedule to run on every Monday at 4:30am:
ucr set cron/backup/time="30 4 * * 1"