Hey nerds,

In this article, we will walk through the process of setting up an Ubuntu 22.04 server. As a computer science student, it's important to understand the technical aspects while keeping the instructions straightforward. Let's dive in!

Step 1: Logging into the Server

For Linux Users:

Open a terminal and use the following command to log in to your server:

ssh -i ssh_key abhishek@<server_ip_address>

For Windows Users:

1. Download and install Putty on your Windows PC.

   

2. Launch Putty and enter the following details:

   • Hostname: <username>@<server_ip_address>

   • Navigate to SSH > Auth and click "Browse" to select the SSH Private Key.

3. Click "Open" to establish the SSH connection.

Congratulations! You have successfully logged into your server.

Step 2: Creating a New User

To create a new user, follow these steps:

1. Run the command:

    sudo adduser <username>
   

   Replace <username> with the desired username for the new user.

2. Grant administrative privileges to the new user:

    usermod -aG sudo <username>
   

Great! You have created a new user with administrative privileges.

Step 3: Setting Up the Firewall

Now, let's set up a firewall to enhance server security:

1. Check the available application profiles:

    ufw app list
   

2. Allow OpenSSH, HTTP, and HTTPS traffic:

    ufw allow OpenSSH
    ufw allow http
    ufw allow https
   

3. Enable the firewall:

    ufw enable
   

4. Verify the firewall status:

    ufw status
   

   If the output matches the following, your firewall is correctly configured:

    Status: active
   
    To                         Action      From
    --                         ------      ----
    OpenSSH                    ALLOW       Anywhere                  
    80/tcp                     ALLOW       Anywhere                  
    443                        ALLOW       Anywhere                  
    OpenSSH (v6)               ALLOW       Anywhere (v6)             
    80/tcp (v6)                ALLOW       Anywhere (v6)             
    443 (v6)                   ALLOW       Anywhere (v6)
   

Step 4: Setting Up SSH Key in Ubuntu Server

To set up SSH key-based authentication, follow these steps:

Create a new SSH key pair using ssh-keygen:

1.     ssh-keygen
   

   This generates two files: the public key (.pub extension) and the private key (no extension).

2. Switch to the new user:

    su - <username>
   

3. Create the necessary directory structure for SSH:

    mkdir ~/.ssh
    chmod 700 ~/.ssh
    touch ~/.ssh/authorized_keys
    chmod 600 ~/.ssh/authorized_keys
   

4. Open the authorized_keys file:

    nano ~/.ssh/authorized_keys
   

5. Copy and paste the content of the .pub file into the authorized_keys file and save it (CTRL+S).

6. Log in to your server using SSH with the private key:

    ssh -i <privatekeyfile> <username>@<server_ip_address>
   

Fantastic! You have successfully set up SSH key-based authentication.

Conclusion: By following this technical yet straightforward guide, you have now set up an Ubuntu 22.04 server, created a new user with administrative privileges, configured a firewall, and enabled SSH key-based authentication.

Happy exploring and learning on your new server!