Basic Linux Shell Scripting for DevOps Engineer
Shell Scripting for DevOps
Shell scripting can be defined as a plain text file that contains a series of Linux commands and shell statements. Shell scripts are used to automate tasks, which can save you time and effort and help you to be more efficient.
You write a shell script when you have a task that is complex or difficult to remember, and you want to be able to do it without having to think about it every time.
Shell scripting is a versatile and powerful programming language that DevOps engineers can use to automate a wide range of tasks, from basic to complex.
Importance of Shell Scripting
By automating a complex task with a shell script, you can reduce the risk of errors and make the task easier and faster to do.
You can save time and effort by not having to re-learn how to do the tasks every time you need to do them.
Using a good shell script reduces the chance of errors.
Shell Scripting can be used for the following
Provisioning and configuring servers: Provisioning and server configuration can be a time-consuming and error-prone task if done manually, but shell scripting can make it much faster and more reliable. Shell scripts can be used to automate a wide variety of tasks related to provisioning and configuring servers. For example, you could write shell scripts to:
Create and configure user accounts
Set up networking
Install and configure other software applications
Deploy applications to the server
Monitor the server's performance and health
Deploying and Updating applications: The process of deploying and updating applications can be a complex and time-consuming task if done manually, but shell scripting can make it much faster and more reliable. For example, you could write shell scripts to:
Create and configure database schemas
Set up application permissions
Configure load balancing and caching
Roll out application updates in a phased approach
Monitor the deployment process and send alerts if there are any problems
Automating system administration tasks: Shell scripts can be used to automate a wide variety of system administration tasks. For example, you could write shell scripts to:
Monitor the system's performance and health and send alerts if there are any problems
Troubleshoot problems by collecting and analyzing system logs
Monitoring and troubleshooting systems: Shell scripts can be used to automate a wide variety of monitoring and troubleshooting tasks. For example, you could write shell scripts to:
Monitor the availability of critical services
Monitor system disk space usage
Collect and analyze error logs
Automate the process of restarting failed services
Automate the process of collecting and analyzing performance data
Creating custom CI/CD pipelines: Continuous integration (CI) and continuous delivery (CD) are DevOps practices that automate the software development and delivery process. CI/CD pipelines help to deliver software faster and more reliably. Shell scripting can be used to create custom CI/CD pipelines. This can give you more flexibility and control over the software delivery process.
Shell scripts can be used to automate a wide variety of CI/CD tasks. For example, you could write shell scripts to
Deploy the application to different environments, such as staging and production.
Roll out application updates in a phased approach.
Execute a range of tests, including unit tests, integration tests, and end-to-end tests, to assess the quality of your software at different levels.
Monitor the deployment process and send alerts if there are any problems.
Some of the benefits of using shell scripting for creating custom CI/CD pipelines include:
Flexibility: Shell scripting gives you more flexibility and control over the software delivery process.
Efficiency: Shell scripting can help you to automate repetitive tasks and streamline the software delivery process.
Scalability: Shell scripts can be used to make your CI/CD pipelines more scalable so that they can handle the increased workload of a growing organization.
What is #!/bin/bash?
#!/bin/bash, which is also called a shebang line, is a special line at the beginning of a shell script that informs the operating system which shell interpreter to use to run the script. The Bash shell (Bourne Shell) is a powerful and versatile command-line interpreter that is popular among Linux and macOS users.
Can we write #!/bin/sh as well?
Yes, you can write #!/bin/sh as well. The shebang line #!/bin/sh tells the operating system to use the Bourne shell to execute the script. The Bourne shell is the default shell on many Unix and Linux systems.
However, it is generally recommended to use #!/bin/bash instead of #!/bin/sh unless you have a specific reason to do otherwise. The Bash shell is a superset of the Bourne shell, and it is more powerful and versatile.
Tasks to be carried out
Write a Shell Script which prints
I will complete #90DaysOofDevOps challenge
Print
Write a Shell Script to take user input, input from arguments and print the variables.
Print
Write an Example of If else in Shell Scripting by comparing 2 numbers
Print
Thanks for reading!