public/subjects/devops/auto-jobs

auto-jobs

Instructions

In this exercise, you will create four files called task1, task2, task3, and task4, which will contain the necessary formulas to set up a group of scheduled tasks in the group

task1:

Time: Every Friday, at 20:41 Command: echo "01"

task2:

Time: Every minute Command: sh /home/user01/check

task3:

Time: Everyday midnight at 12 AM Command: sh /home/user01/backup

task4:

Time: After Every Reboot Command: 01exec

All file content must be in this format:

$ cat task-example | cat -e
* * * * * {command}$
$

Once it is done, use the command below to create the file auto-jobs.tar to be submitted.

$ tar -cf auto-jobs.tar task1 task2 task3 task4
$ ls
task1 task2 task3 task4 auto-jobs.tar

Only auto-jobs.tar should be submitted.

Hints

Linux Cron utility is an effective way to schedule a routine background job at a specific time and/or day on an on-going basis.

You can use the crontab command to manage your jobs. This command can be called in four different ways:

crontab -l: List the jobs for the current user crontab -r: Remove all jobs for the current users. crontab -e: Edit jobs for the current user.

Linux Crontab Format:

MIN HOUR DOM MON DOW CMD

Table: Crontab Fields (Linux Crontab Syntax):

Field	Description	Allowed Value
MIN	Minute field	0 to 59
HOUR	Hour field	0 to 23
DOM	Day of month	1-31
MON	Month field	1-12
DOW	Day Of Week	0-6
CMD	Command	Any command to be executed.

Examples:

1. Schedule a job every hour at the fifth minute, every day: 5 * * * * {command}

2. Schedule a job 5 minutes after midnight every day: 5 0 * * * {command}

You have to use Man or Google to know more about commands flags, in order to solve this exercise! Google and Man will be your friends!

References

• an editor for cron schedule expressions.