What is bash scripting?

Bash scripting is a method of automating tasks on Unix-like operating systems using the Bash shell. It involves writing sequences of commands in a script to streamline and automate repetitive tasks, making system administration and other routine processes more efficient.

Let's create a Script:

Steps:

1. Create directory bashscripts.

2. Copy the below Vagrantfile to it

    Vagrant.configure("2") do |config|
        config.vm.define "scriptbox" do |scriptbox|    
        scriptbox.vm.box = "jacobw/fedora35-arm64"
        scriptbox.vm.network "private_network", ip: "192.168.56.26"
        scriptbox.vm.hostname = "scriptbox"
        scriptbox.vm.provider "vmware_desktop" do |v|
          v.allowlist_verified = true
          v.ssh_info_public = true
            v.gui = true
        end
        scriptbox.vm.provision "shell", inline: <<-SHELL
         mv /etc/yum.repos.d/fedora-updates.repo /tmp/
         mv /etc/yum.repos.d/fedora-updates-modular.repo /tmp/
         yum clean all
         yum update
         systemctl stop firewalld
        SHELL
      end
        config.vm.define "web01" do |web01|    
        web01.vm.box = "jacobw/fedora35-arm64"
        web01.vm.network "private_network", ip: "192.168.56.27"
        web01.vm.hostname = "web01"
        web01.vm.provider "vmware_desktop" do |v|
          v.allowlist_verified = true
          v.ssh_info_public = true
            v.gui = true
        end
        web01.vm.provision "shell", inline: <<-SHELL
         mv /etc/yum.repos.d/fedora-updates.repo /tmp/
         mv /etc/yum.repos.d/fedora-updates-modular.repo /tmp/
         yum clean all
         yum update
         systemctl stop firewalld
        SHELL
      end
        config.vm.define "web02" do |web02|    
        web02.vm.box = "jacobw/fedora35-arm64"
        web02.vm.network "private_network", ip: "192.168.56.28"
        web02.vm.hostname = "web02"
        web02.vm.provider "vmware_desktop" do |v|
          v.allowlist_verified = true
          v.ssh_info_public = true
            v.gui = true
        end
        web02.vm.provision "shell", inline: <<-SHELL
         mv /etc/yum.repos.d/fedora-updates.repo /tmp/
         mv /etc/yum.repos.d/fedora-updates-modular.repo /tmp/
         yum clean all
         yum update
         systemctl stop firewalld
        SHELL
      end
        config.vm.define "web03" do |web03|    
        web03.vm.box = "spox/ubuntu-arm" 
        web03.vm.box_version = "1.0.0"
        web03.vm.network "private_network", ip: "192.168.56.29"
        web03.vm.hostname = "web03"
        web03.vm.provider "vmware_desktop" do |v|
          v.allowlist_verified = true
          v.ssh_info_public = true
            v.gui = true
        end
      end
    end
   

3. Do vagrant up scriptbox and vagrant ssh to login.

4. Do sudo -i to go to root user.

5. Create a directory using mkdir /opt/scripts .

6. cd into it using cd /opt/scripts .

7. Do vim firstscript.sh . sh is the extension for shell script but it is not necessary.

8. Enter the below script into it -

    #! /bin/bash
    # The above line is called a shebang, indicating that the script should be interpreted using the Bash shell.
   
    echo "Welcome to bash script"
    # Print a welcome message to the console.
   
    echo
    # Print an empty line for better readability in the console.
   
    echo "The uptime of the system is: "
    uptime
    # Display the system uptime using the 'uptime' command.
   
    echo "Memory Utilization"
    free -m
    # Display memory utilization using the 'free' command with the '-m' option to show results in megabytes.
   
    echo "Disk Utilization"
    df -h
    # Display disk utilization using the 'df' command with the '-h' option to show results in a human-readable format.
   

9. Do ./firstscript.sh you will get permission denied because it does not have execute permission

   

10. So give permission using chmod +x firstscript.sh .

11. Run ./firstscript.sh to see the output.

Setup a website using script:

Steps:

1. Create the script using vim /opt/scripts/websetup.sh .

2. Copy the below contents in the script -

    #! /bin/bash
   
    ######## Install required packages ########
    sudo yum install wget unzip httpd -y
   
    ######## Start and enable Apache HTTP server ########
    sudo systemctl start httpd
    sudo systemctl enable httpd
   
    ######## Create a temporary directory for web files ########
    mkdir -p /tmp/webfiles
    cd /tmp/webfiles
   
    ######## Download and extract a web template ########
    wget https://www.tooplate.com/zip-templates/2136_kool_form_pack.zip
    unzip 2136_kool_form_pack
   
    ######## Copy the extracted files to the web server's directory ########
    sudo cp -r 2136_kool_form_pack/* /var/www/html/
   
    ######## Restart the Apache HTTP server to apply changes ########
    sudo systemctl restart httpd
   
    ######## Clean up: Remove the temporary directory ########
    rm -rf /tmp/webfiles
   

3. Execute using /opt/scripts/websetup.sh .

4. Get the IP address of the VM and paste it on the browser to see the website live.

This is how script makes the process is !!!