DevOps, Day - 5

1. Shell script to create multiple directories at once

   

   Here $1 is directory_name(d)
   $2 is start_directory(1)
   $3 is end_directory(90)
   After executing this code, we get the output as...

   

2. Script to backup all work done till now

   Try these steps to back up all your work done till now...

   step 1: create a backup script.

   Example: I created a back_up.sh script that includes the current date and time.
   I used the built-in-tool called tar (tape archive) which can create compressed archive files that contain 1 or more files or directories.
   Here is the simple script...

   

   step 2: I saved the script in /home/Krishna/Desktop/d1 path
   you can save the script in your desired directory.

   step 3: Assign execute permission for the script using chmod

   step 4: List all the files using ls and execute the script as ./back_up.sh

   step 5: Now list the contents again using ls

   step 6: Now we can see the back_up file named backup23-03-28-00-28-49.tar.gz
   step 7: Use ls -l backup23-03-28-00-28-49.tar.gz

   Hence, you can visit the directory in your system, and check for a back_up file.

   Below you can see the flow

   

   Before Back_up

   

   After Back_up

   

3. cron & crontab to automate the backup script

   what is cron?
   cron is a time-based scheduling utility in Linux.

   It allows you to automate repetitive tasks by running commands or scripts at specified intervals.

   cron is an essential tool for system administrators to improve system efficiency and reduce the risk of human error.

   What is crontab?
   crontab is a file that contains a list of commands or scripts scheduled to run automatically using cron in Linux.

   The crontab file can be edited using the crontab command to specify the schedule, command, and output redirection for each job.

   crontab is a powerful tool for automating repetitive tasks in Linux and can help improve system efficiency and reduce the risk of manual errors.

   Commands of crontab
   crontab -l [ to show all the current jobs ]
   crontab -e [ to edit or add new jobs ]

   cron job format

   

   Steps to create & use crontabs.

   Create any desired file

   Example: I created a task.sh script, which creates a file based on date & time.

   

   step1: type crontab -l // to list the existing cronjobs

   step2: type crontab -e // select an editor and write your desired scheduling task

   * * * * * /home/krishna/Desktop/d1/task.sh

   step3: sudo service cron status // to check the cronjob status

   

   step4: sudo service cron start // to start the cronjob

   

   step5: type ls //now the task will be running

   

   step6: type crontab -r // to stop the cronjob

   

4. User management

   User management in Linux is the way we create, modify, and delete user accounts on a Linux system. It helps control user access to system resources and ensures the security and stability of the system. It involves setting up user accounts with appropriate permissions, managing user passwords, and using tools to manage users and groups.

   • User accounts are used to access a Linux system, and user management involves creating, modifying, and deleting these accounts.

   • User accounts are associated with a username, password, and unique user ID (UID).

   • User accounts can be assigned to one or more groups, which determine the user's access to system resources.

   • User management includes setting permissions for files and directories to control user access to them.

   • User management is essential for system security, as it allows administrators to restrict access to sensitive information and prevent unauthorized actions by users.

5. Create 2 users & just display their usernames

   step 1:

   

   step 2: After this type password and user1 is created.

   step 3: Do the same for another user

   

   step 4: To check, whether both users are added, we use the following command

   

   

   Finally, we can see both the users added in the last line.

   step 5: set a password for the users created newly.

   Do the same for all other users created newly, or else the user will not be visible on the login screen.

   

   After setting the password, we can see the user1 on the login screen.

   

Thank you so much for reading

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