bash_scripting

Backup, User and Group Management, String Manipulation with Linux Commands and Bash Scripting

Part 1: Security Issue : You are working in a Financial Company as DevSecOps. Recently, one of your instances has been terminated by someone within the firm. That instance was very important for firm's web-app and also your infrastructure has been affected by this termination. Your team lead is suspecting Serdar user. You have assigned to find instances' ids terminated by Serdar user. You have Cloudtrail event history file named event_history.csv. Instance ids within this event history look like i-0c127ab5cdf997cf4. You have to apply some filtering and string manipulation commands to find ids. To be able to handle this tasks, you decided to create a bash script, then, save instances' ids terminated by Serdar user in result.txt file.

Part 2: User and Password Script : You're working as a System Administrator for a e-commerce company. The latest company initiative requires you to write an ansible file for dozens of servers. You're falling behind schedule and are going to miss your deadline for these ansible files because you are constantly being interrupted by the HR calling you to create new Linux accounts for all the people in the company who have been recruited to test out the company's newest Linux-based application.

In order to meet your deadline and keep your sanity, you decide to write a shell script that will create new user account and automatically generate a password for each of new account. Once you're done with the shell script you can put the HR in charge of creating new accounts which will finally allow you to work uninterrupted and complete your server deployments on time.

Your script accepts user account name and comments as parameter. Then create a new user and a password for them. At the same time, you want users to change their password, when they login the system at the first time. Please create this bash scripting file named user_password.sh.

Part 3: Baking up and Cronjob : Imagine that you are working in Gaming company as DevOps Engineer. Recently, you have deployed a new version of firm's famous Game and it's content are being kept under /home/ec2-user/data in minute basis. In addition, your manager asked you to be backed /etc, /boot, and /usr up as well. So, /home/ec2-user/data, /etc, /boot, and /usr folders need to be backed up and placed in specific folder /mnt/backup in every 5 minutes. At the same time, since you should separate each file from others, you have to assign different name to backup files based on hostname of instance and the date-hour-minute of the backup. Each backup file has to be compressed with .tgz extension. You can not manage this dynamic process by yourself. You decided to create a bash script and define cronjob for executing this in every 5 minutes. Files which are /home/ec2-user/data, /etc, /boot, /usr have to be backed up. Please write a bash script named backup.sh for this task.

Part 4: String Manipulation : You are working in Healthcare Company as DevOps engineer. Recently, you have been assigned some tasks by your manager. This part has 3 different tasks. Please follow the problem statements.

Task 1: You are writing an ansible playbook file and an ec2 instance is created one part of it. Than you have a description file named info.json belonging to newly created ec2 instance. Some steps later, to be able to create a git repository with terraform.tf file, you need to pass private IP of newly created ec2 instance to environmental variable which is ec2_private_ip on the line 40. You must not open terraform.tf file and paste the IP taken from info.json in related part. You have to do all those acts with linux commands and you must not open terraform and json files. Please take the private IP of EC2 instance from ec2 description file (info.json) and change the ec2_private_ip value with it within terraform.tf file.

Task 2: Again you are writing an Ansible playbook file. In one part of that file, a pem key is created and app gives you that file one line format like certificate.pem. You have to turn it into multi line format to use it in another place of ansible file. Please get that certificate.pem one line pem key file and create and copy its multiline format in new.pem file.

Task 3: You have audit log file which has ssh connection logs to your server. However some invalid users try to connect your system. You have been assigned a task to find their names and how many times have they tried to attack your system. Please find it and put it into the invalid_user.shfile.

Project Skeleton Linux_Projects (folder)

|----First_Part |--------event_history.csv # Given to the students |--------result.txt # To be delivered by students |--------script.sh # To be delivered by students

|----Second_Part |--------user_password.sh # To be delivered by students

|----Third_Part
|--------backup.sh # To be delivered by students

MineGumus/BashScripting

bash_scripting