Rocky Linux is an open-source Linux distribution developed by Rocky Enterprise Software Foundation. It is an enterprise OS intended to be a downstream, complete binary-compatible release that uses the Red Hat Enterprise Linux OS source code.

Step 1: Download the ISO Image

Using a browser of your choice, browse to https://rockylinux.org/download/ and, depending on your system and use case, select one of the available ISO image downloads:

For this tutorial, we will install Rocky Linux on a 64-bit architecture. We have downloaded the DVD ISO image, which contains the BaseOS and AppStream repositories.

The Boot and Minimal versions are used when installing the OS from another source (such as an HTTP repository of the binary files) or to enter Rescue Mode.

Step 2: Create Bootable USB Drive

Depending on which system you will create the bootable USB drive, use one of the following tools:

Rufus on Windows

1. Browse to https://rufus.ie/en/# and download the latest Rufus version. For this tutorial, we will use the portable version:

2. Open Rufus and insert a USB stick. The program automatically recognizes and selects it.

3. Click the SELECT button and select the Rocky Linux 9 ISO image you have previously downloaded.

4. Click START to write the ISO image and create a bootable USB drive.

Startup Disk Creator on Ubuntu Linux

1. Click the Show Applications button, and in the search dialog type Startup Disk Creator.

2. In the Source disc image section, click Other. Select the Rocky Linux ISO image you have previously downloaded.

3. In the Disk to Use section, select your USB drive.

4. Click Make Startup Disk and wait for the process to complete.

Step 3: Boot up Rocky Linux from the USB

To boot up Rocky Linux from the USB, follow the steps below:

1. Insert the Rocky Linux USB drive.

2. Turn on the machine or restart the system. The USB drive should boot automatically. If it does, skip the next step.

If the USB doesn’t boot, manually select the USB boot device in the Boot Menu or BIOS/UEFI.

3. Access the boot menu by tapping the designated boot key for your machine as soon as the computer turns on. The key differs based on the machine vendor, so Google the one for your device.

4. Select the USB boot device using the arrow keys in the boot menu. The system starts loading the Rocky Linux installation menu.

Step 4: Install Rocky Linux

After booting to the installation menu, start the installation by selecting Install Rocky Linux 9.0.

Choose Installation Language

Once the Rocky Linux Anaconda installer loads, the Welcome page prompts you to choose the language for the installation process. After selecting, press Continue.

Installation Menu

The installation summary menu appears with crucial parameters that need to be configured before the installation.

Select each item to configure the specified setting and click Begin Installation when finished. The sections below explain each of the configurable parameters.

Keyboard Layout Selection

Select the Keyboard option to add keyboard layouts. The default keyboard configuration depends on which language you selected. Click the + button to add a keyboard layout aside from the default one.

• You can also test the keyboard in the textbox on the right to ensure it is the correct layout.
• When finished, click Done to go back to the installation menu.

• Language Support
• Select the Language Support menu item to install additional UI languages. When finished, click Done.

• Time and Date

Select the Time & Date option to set up the time and date. The installer automatically detects the region and time zone if you have internet access. Alternatively, set the parameters manually by selecting the region and city from the dropdown menu and set the time and date in the bottom part of the screen.

Turn on the Network Time switch to keep the time and date synchronized with the internet time.

When finished, click Done to save the changes and go back.

Software Selection

• Under the SOFTWARE section, click the Software Selection item to select which base environment and additional software to install.
• Depending on your use case and base environment, choose between debugging tools, the DNS Name Server packages, FTP server tools, etc.

When finished, click Done to return to the installation menu.

Installation Destination

Under the SYSTEM section, click the Installation Destination item to select and partition the hard disk for the installation. Ensure that the disk on which you are installing Rocky Linux has a checkmark.

Under Storage Configuration, choose whether to configure the storage automatically or if you want to create custom partitions. If you choose Custom, click Done, and the Manual Partitioning window appears.

Manual Partitioning

In the Manual Partitioning window, create the custom partitions for your OS and select a file system type.

1. In the dropdown menu, select Standard Partition as the partitioning scheme:

2. Click the + button to add a new partition.

For this installation, we will create the following partitions:

• /home – 20 GiB
• /boot – 1 GiB
• swap – 8 GiB

Add each partition by clicking the + button and specifying the size. Click the Add mount point button to create the partition.

3. When finished, click Done to exit the partition manager.

4. A window appears showing the summary of changes to be written to disk:

Click Accept Changes to proceed with the partitioning or Cancel to return and make changes to the partitions. When the partitioning finishes, the wizard returns to the installation menu.

Root Password

Under the USER SETTINGS section, click the Root Password item to set up an administrator password for the system. Enter the password and confirm it. Remote logins via SSH are disabled by default. Check the Allow root SSH login with password option to enable it.

The password strength indicator shows whether the password is strong enough. After setting up the password, click Done to return to the installation menu and begin the installation.

User Creation

Under USER SETTINGS, click the User Creation item to create a user for the OS. Enter a name, and choose a login username and password. Retype the password and check the password strength indicator.

• To make the user a system administrator, check the Make this user administrator box.
• When finished, click Done to save the changes.

Install Rocky Linux

After configuring all the settings in the installation menu, click the Begin Installation button to start installing Rocky Linux.

When the installation completes, take out the USB drive and click the Reboot System button to boot into the fresh Rocky Linux 9 installation on your machine:

• After the system boots, a login screen appears with the user account(s) you have created.
• Click the user you want to log in to and provide the password:

The installation is complete. You can start using Rocky Linux on your machine.

Linux just like other operating systems is widely used especially when it comes to software development, coding, and some other similar applications. Rocky Linux is one of the Linux distributions, it is based on Cent-OS and is named Rocky after one of its co-founders.

Installing Rocky 9 Linux on VirtualBox

Rocky 9 comes with 10-year free support program and provides the opportunity to Linux users to migrate from other Linux distributions free of charge, here are some steps that one needs to follow to install this Linux on VirtualBox:

Step 1: Visit the official website of Rocky Linux and click on Download 9.0 to move download section:

Step 2: Next, select the suitable architecture and download the torrent file do not go for the minimal option as it only comes with the terminal version of Rocky:

Step 3: Once the file is downloaded run the VirtualBox and click on New option from the top:

Step 4: Next Name your virtual machine and select the suitable directory under the Machine Folder:

Now select the Type of operating system that is Linux:

Step 5: Next select the version of operating system that is other Linux (64-bit):

Once you have selected all the relevant information then click on Next:

Step 6: Now assign the RAM for your virtual machine for instance I have given the RAM of 8GB:

Step 7: Next, choose the type of hard disk for virtual machine by selecting Create a virtual hard disk now and after that click on the Create option:

Step 8: Now select the VHD (virtual hard disk) as the file type and click on Next:

Step 9: Next, select the type of size of physical hard and for that select the Dynamically allocated option and then click on Next:

Step 10: Now allocate the storage size for the virtual machine and try to set it about almost 20GB in order to make the installation process run smoothly:

Step 11: Now the virtual machine is created so next click on Start button from the top:

Step 12: First under the start-up disk click on the folder icon to select the disk image, from there in the Optical Disk Selector click on ADD and then select the downloaded file. After that click on Open and the respective file will be selected.

Step 13: Now click on Start to further move to the installation process:

Step 14: Next, select the Install Rocky Linux 9.0 to begin the installation process:

The installation process will start and take time:

Step 15: Next, select the suitable language:

Once you have selected the language click on Continue:

Step 16: Now complete the settings of the option that are highlighted one of which is the Installation Destination click on it:

Next select the hard drive and keep the Storage Configuration to Automatic after that click on Done:

Step 17: The next option that is highlighted is the Root Password, click on it:

Set the Root Password and click on Done:

Step 18: Now click on Begin Installation:

The installation process will start, it might take some time, so wait:

When the installation is complete click on Reboot System:

Step 19: Once the system is rebooted click on the Start setup:

Step 20: Turn on the Location Services and click on Next to proceed further:

Step 21: Now add the any of your Online account or click on Skip:

Step 22: Now set the Full Name and the Username and click on Next

Step 23: Now Set a Password for your virtual machine and select Next:

Now the setup is complete and then click on Start Using Rocky Linux:

Oracle’s free and open-source offering VirtualBox is an excellent virtualization tool, especially for desktop operating systems. You can use virtualization software like VirtualBox for installing and using another operating system within a virtual machine. You can also use VirtualBox for installing another Linux distribution within your current Linux system.

The easiest way to install VirtualBox on Ubuntu is to search for it in the Software Center and install it from there.

You can also install it from the command line using this command:

sudo apt install virtualbox

However, if you check the package version before installing it, you’ll see that the VirtualBox provided by Ubuntu’s repository is quite old.

For example, the current VirtualBox version at the time of writing is 7.0, but the one in Software Center is 6.2. This means you won’t get the newer features introduced in the latest version of VirtualBox.

Install VirtualBox using deb file from Oracle’s website

If you want to use the latest version of VirtualBox on Ubuntu, the easiest way would be to use the deb file. Oracle provides ready-to-use binary files for VirtualBox releases. If you look at its download page, you’ll see the option to download the deb installer files for Ubuntu and other distributions.

You just have to download this deb file and double-click on it to install it. It’s as simple as that. However, the problem with this method is that you won’t get automatically updated to newer VirtualBox releases. The only way is to remove the existing version, download the newer version and install it again.

Install VirtualBox using Oracle’s repository

First, add the key for the repository. You can download and add the key using this single command.

wget -q https://www.virtualbox.org/download/oracle_vbox_2016.asc -O- | sudo apt-key add -

sudo add-apt-repository "deb [arch=amd64] http://download.virtualbox.org/virtualbox/debian $(lsb_release -cs) contrib"

sudo apt update && sudo apt install virtualbox-7.0

VirtualBox is open-source virtualization software from Oracle for creating virtual machines. With a virtual machine, you can run an operating system like an application inside your current operating system. It’s like a computer inside a computer.

These are called virtual machines because they’re basically emulating other operating systems, but they’re not really interacting with the computer system like a true operating system would.

Before installing Windows 10 in VirtualBox, let’s see what you need first:

• An internet connection with good speed, or a Windows 10 ISO that you’ve already downloaded.
• At least 4 GB of RAM. The more RAM you’ve got, the better.
• Around 20 GB of free storage for installing Windows 10.

Step 1: Download Windows 10 ISO

First and foremost, you need to download a Windows 10 ISO. You can download Windows 10 32-bit or 64-bit, depending on your system.

Step 2: Install VirtualBox on Ubuntu and Linux Mint

It’s very easy to install VirtualBox on Ubuntu. All you need to do is to use the command below:

sudo apt install virtualbox

Step 3: Install Windows 10 in VirtualBox

Start VirtualBox. You should see a screen like the one below.

Name the VM anything you like. Also select the operating system and version. In this case I’ve chosen Windows 10 and 64-bit.

Choose the RAM size. The recommended RAM size for 64-bit Windows 10 is 2 GB, while for 32-bit Windows 10 it’s 1 GB. But I suggest you have a little more than that for a smoother experience.

As a beginner, you may need to know how to change any default application in Ubuntu and this is what I am going to show you in this tutorial.

There are basically two ways you can change the default applications in Ubuntu:

• via system settings (valid for changing the default web browser, email client, calendar, music application, video player and image viewer)
• via right-click menu (valid for applications other than the above mentioned ones)

1. Change default applications in Ubuntu from System Settings

Simply head to the System Settings:

In the System Settings, click on the Details option:

Now, click on the “Default Applications” option as highlighted in the screenshot below:

As you can see, there are only a few kinds of default applications that can be changed here. You can change the default applications for web browsers, email clients, calendar apps, music, videos and photo here. What about other kinds of applications?

2. Change default applications in Ubuntu from right-click menu

Let’s say you have a markdown file (.md) which opens in Gedit text editor by default. But you want to use some other applications to open markdown files. Here’s what you need to do.

Right click on the file and then select Open with Other Application:

If you don’t see your choice of application, click on the View All Applications:

Locate the desire application and select it:

• This will open the file in your chosen application.
• The thing here is that the file manager automatically recognizes your choice and the next time you double click on the file to open it, it will open it with the application you last chose.

Keep in mind that this behavior is not applicable to web browser, music player, video player, email client, calendar and photo viewer. For that you need to use the first method.

Have you ever gotten that horrible feeling? The one you get when you realize that you accidentally deleted files and it’s not even in the trash? Often it is immediately preceded by denial: I know I have another copy of it somewhere.

You need to install the TestDisk tool first. Most Linux distributions already have this tool in their official repository. In Ubuntu and other Ubuntu-based Linux distributions such as Linux Mint, elementary OS etc, you can use the command below to install TestDisk:

sudo apt install testdisk

Arch Linux users can install it from AUR. You can download it for other Linux distributions from the link below:

https://www.cgsecurity.org/wiki/TestDisk_Download

Run TestDisk in the terminal using the command below:

testdisk

When you open it, you’ll see something that looks like this. Be patient! The interface is actually straightforward but you do have to carefully read the text. Use the arrow keys to navigate and “enter” to select.

Now, at this point, if you’re lucky, you should see your drive. And you can proceed to the last steps. But let’s assume you’re not, that you have, say, a multi-boot machine. In this case, ownerships can get blurry, and Testdisk needs your permission to open them.

Testdisk has again selected the correct setting. This makes sense since a simple storage device is seldom partitioned. Again hit enter.

And finally, we have to do a little thinking to do. If you read the first screen, this program isn’t just for recovering deleted files. It’s a powerful disk utility. But if we remember what we’re trying to do the choice is fairly obvious: we’re not trying to fix a disk, we’re trying to recover a file. Select “Advanced” and hit “enter”.

The AWS CLI is an essential tool for developers and sysadmin to automate and interact with AWS cloud services. It is an open-source tool built on the AWS SDL for Python. As a result, you no longer need to use AWS Management Console. Instead, you can use Linux terminal and commands for managing AWS resources.

Installing AWS cli on Linux

1. Open the terminal application.
2. Then type command as per your Linux distro to install aws cli kit:
   1. Debian/Ubuntu Linux user, type:$ sudo apt install awscli
   2. Fedora Linux user, type:$ sudo dnf install awscli
   3. RHEL/CentOS/Rokcy/Alma Linux user, type (first, turn on ELEP repo and then):$ sudo dnf install awscli
   4. Alpine Linux user, type:# apk add aws-cli
   5. Arch Linux user, type:$ sudo pacman -S aws-cli
   6. OpenSUSE/SUSE Linux user, type:$ sudo zypper in aws-cli
   7. Install AWS CLI version 1.x using PIP generic method:$ python3 -m pip install awscliDo you want AWS cli version 2? Try:$ python3 -m pip install awscliv2
$ ~/.local/bin/awscliv2 --installMake sure you include ~/.local/bin/ in your $PATH. For example, here is how to set up PATH on your Linux:# Step #1. Set PATH variable #
$ echo 'export PATH=$PATH:~/.local/bin' >>~/.bashrc
# Step #2. Set bash alias too #
$ echo 'alias aws="awsv2"' >>~/.bashrc
# Step #3. Use the source command to load changes #
$ source ~/.bashrc
3. Once installed, find out AWS CLI version, run:$ aws --versionDepending upon your package manager and Linux distro, you may get the latest or older version. For instance, here is the output from my Ubuntu 20.04 LTS developer workstation:

   aws-cli/1.18.69 Python/3.8.10 Linux/5.13.0-35-generic botocore/1.16.19

   Here is outputs from v2:

   2.1.1
   AWS CLI v2 command: /home/ubuntu/.awscliv2/binaries/aws
   aws-cli/2.4.28 Python/3.8.8 Linux/5.13.0-37-generic exe/x86_64.ubuntu.22 prompt/off

4. Next, you need to configure AWS cli with API keys. Log in to the AWS management console and grab API access keys if you don’t have any. Then configure it as follows:$ aws configure
5. So far, you have installed AWS cli. Then configured access, and now it is time to test it. First, I will run the ‘aws s3 ls’ command to list your aws s3 resources:$ aws s3 ls
   Here is what I see when everything is configured correctly:

   2016-07-25 16:11:06 xyz-project-freenas
   2020-07-03 13:55:47 xyz-project-forum
   ....
   ..

A note about credentials file

Your aws CLI credentials are stored in plain text inside ~/.aws/ directory. Therefore, do not share ~/.aws/ directory and files. You can view it using the cat command:
$ cat ~/.aws/credentials
It is possible to store credentials in an encrypted format. The other option is to use and enable AWS Multi-Factor Authentication (MFA). It is a best practice that adds an extra layer of protection for your credentials.

What are JSON and CSV formats?

JSON is an acronym for JavaScript Object Notation. Often used in web apps, but it is not limited to JavaScript. One can use any programming language such as Perl, Python or CLI tools such as jq. CSV is an acronym for Comma-separated values. It is a text file you can use in spreadsheet apps, programming languages and many other apps.

Example of JSON format

Here the outputs of the df command in JSON format:

[
  {
    "fs": "/dev/mapper/vgubuntu-root",
    "type": "ext4",
    "size": "915G",
    "used": "135G",
    "avail": "734G",
    "usedpercentage": "16%",
    "mounted": "/"
  },
  {
    "fs": "/dev/nvme0n1p2",
    "type": "ext4",
    "size": "1.4G",
    "used": "378M",
    "avail": "939M",
    "usedpercentage": "29%",
    "mounted": "/boot"
  },
  {
    "fs": "/dev/nvme0n1p1",
    "type": "vfat",
    "size": "511M",
    "used": "30M",
    "avail": "482M",
    "usedpercentage": "6%",
    "mounted": "/boot/efi"
  }
]

Example of CSV format

The JSON outputs in CSV format (all values are separated by a comma , value):

/dev/mapper/vgubuntu-root,ext4,915G,135G,734G,16%,/
/dev/nvme0n1p2,ext4,1.4G,378M,939M,29%,/boot
/dev/nvme0n1p1,vfat,511M,30M,482M,6%,/boot/efi

Converting JSON to CSV using Linux / Unix shell

So how do you convert such input? The answer is to use jq or dasel command-line utilities.

Installing jq

Since jq is available in most common repos, I will use that one for my needs. Here is how to install jq on a Debian or Ubuntu Linux using the apt command/apt-get command:
$ sudo apt install jq
RHEL/Fedora/CentOS/Alma/Rocky Linux user try the dnf command:
$ sudo dnf install jq
Alpine Linux user try the apk command:
$ sudo apk add jq
SUSE or OpenSUSE Linux user try the zypper command:
$ sudo zypper in jq
macOS / OS X user install homebrew and then use the brew command:
$ brew install jq

Example – convert JSON to CSV under Linux

The syntax is as for df.json:
$ cat df.json | jq
Now let us extract the fs field, run:
$ cat df.json | jq '.[] | .fs'
How about both fs and type fields?
$ cat df.json | jq '.[] | .fs, .type'

To generate CSV file with , as separator use the following syntax:
$ cat df.json | jq '.[]| join(",")'
The join(",") joins the array of elements given as input, using the argument , as separator:

"/dev/mapper/vgubuntu-root,ext4,915G,135G,734G,16%,/"
"/dev/nvme0n1p2,ext4,1.4G,378M,939M,29%,/boot"
"/dev/nvme0n1p1,vfat,511M,30M,482M,6%,/boot/efi"

Pass the -r raw option to get rid of double quotes:
$ cat df.json | jq -r '.[]| join(",")'

How do I convert a JSON file to CSV?

Let us consider the following file displayed using the bat/cat command$ cat bingbot.json
$ batcat bingbot.json
Sample config:

{
  "creationTime": "2021-11-10T10:00:00.121331",
  "prefixes": [
    {"ipv4Prefix": "157.55.39.0/24"},
    {"ipv4Prefix": "207.46.13.0/24"},
    {"ipv4Prefix": "40.77.167.0/24"},
    {"ipv4Prefix": "13.66.139.0/24"},
    {"ipv4Prefix": "13.66.144.0/24"},
    {"ipv4Prefix": "52.167.144.0/24"},
    {"ipv4Prefix": "13.67.10.16/28"},
    {"ipv4Prefix": "13.69.66.240/28"},
    {"ipv4Prefix": "13.71.172.224/28"},
    {"ipv4Prefix": "139.217.52.0/28"},
    {"ipv4Prefix": "191.233.204.224/28"},
    {"ipv4Prefix": "20.36.108.32/28"},
    {"ipv4Prefix": "20.43.120.16/28"},
    {"ipv4Prefix": "40.79.131.208/28"},
    {"ipv4Prefix": "40.79.186.176/28"},
    {"ipv4Prefix": "52.231.148.0/28"},
    {"ipv4Prefix": "51.8.235.176/28"},
    {"ipv4Prefix": "51.105.67.0/28"}
  ]
}

The final goal is to produce .CSV file as follows: for my WAF:

157.55.39.0/24,BingBot
207.46.13.0/24,BingBot
40.77.167.0/24,BingBot
13.66.139.0/24,BingBot
13.66.144.0/24,BingBot
52.167.144.0/24,BingBot
13.67.10.16/28,BingBot
13.69.66.240/28,BingBot
13.71.172.224/28,BingBot
139.217.52.0/28,BingBot
191.233.204.224/28,BingBot
20.36.108.32/28,BingBot
20.43.120.16/28,BingBot
40.79.131.208/28,BingBot
40.79.186.176/28,BingBot
52.231.148.0/28,BingBot
51.8.235.176/28,BingBot
51.105.67.0/28,BingBot

Commands

First type the following to get CIDR prefixes:
$ cat bingbot.json | jq '.prefixes[]'
Then pipe outputs to create new JSON to add a comment field:
$ cat bingbot.json | jq -r '.prefixes[] | {cidr: .ipv4Prefix, comment: "BingBot"}'
Finally, use the join() to make a .CSV file:
$ cat bingbot.json | jq -r '.prefixes[] | {cidr: .ipv4Prefix, comment: "BingBot"} | join(",")'
Save it:
$ cat bingbot.json | jq -r '.prefixes[] | {cidr: .ipv4Prefix, comment: "BingBot"} | join(",")' > bingbot.csv
Verify it:
$ cat bingbot.csv