Day 4 Task: Basic Linux Shell Scripting for DevOps Engineers.

Day 4 of the 90 Days of DevOps Challenge introduces the vital concept of Linux shell scripting, a cornerstone for DevOps engineers. Understanding its theoretical basis is crucial for mastery.

Understanding Kernel and Shell

What is Kernel?

The kernel is the core component of an operating system, possessing complete control over system functions. It manages resources, executes processes, and serves as an intermediary between software and hardware.

What is Shell?

A shell is a user interface that interprets user commands into a language the kernel comprehends. It acts as a command-line interpreter, executing commands received from the user via input devices or files.

Linux Shell Scripting: The Essence

What is Shell Scripting for DevOps?

Shell scripting in DevOps involves the creation of programs executed by a Linux shell. These scripts automate tasks, manage system resources, and execute commands, vital for system administrators and DevOps engineers.

Tasks Explained

1. Explanation of Shell Scripting for DevOps: Shell scripting in DevOps empowers automation, enabling the execution of repetitive tasks, system administration, and orchestration. For instance, creating scripts for automatic deployments or system maintenance.

2. Understanding #!/bin/bash vs. #!/bin/sh: #!/bin/bash and #!/bin/sh denote the interpreter for the script. While bash is the Bourne Again Shell, sh refers to the Bourne Shell. bash offers more features compared to the traditional sh.

3. Shell Script for the 90 Days of DevOps Challenge:

    bashCopy code#!/bin/bash
    echo "I will complete #90DaysOfDevOps challenge"
   

4. User Input and Variable Printing:

    bashCopy code#!/bin/bash
    echo "Enter your name:"
    read name
    echo "Your name is: $name"
    echo "Arguments passed: $1, $2"
   

5. Illustration of If-Else in Shell Scripting:

    bashCopy code#!/bin/bash
    num1=5
    num2=10
    if [ $num1 -eq $num2 ]
    then
        echo "Numbers are equal"
    else
        echo "Numbers are not equal"
    fi
   

Practical Application and Significance

Shell scripting is an integral tool for automation and execution of various system operations. Understanding its theoretical foundations aids in creating efficient scripts that automate tasks, manage systems, and enhance DevOps practices.

Stay tuned for further insights and practical applications in the 90 Days of DevOps Challenge on Hashnode. We'll continue to explore and apply these fundamental concepts within the realm of DevOps practices and system administration.