Linux Assignment.txt

-----------------------------------------------------------------------------------------------------------------------
In EC2 Ubuntu Instance Create a new user and SSH Key pair with an authorized key
-----------------------------------------------------------------------------------------------------------------------

Connect to Your EC2 Instance

Execute the below command with required path of the pem file
ssh -i /path/to/your-key.pem ubuntu@<EC2-public-IP>

Create a New User
sudo adduser <new-username>

Switch to the New User
sudo su - <new-username>

Create an .ssh Directory for the New User
mkdir ~/.ssh
chmod 700 ~/.ssh

Create an SSH Key Pair (On Local Machine)
Generate an SSH key pair on your local machine (your computer, not the EC2 instance) using the following command:
ssh-keygen -t rsa -b 4096

This command will create a public-private key pair. When prompted, you can either specify a location to save the key or press Enter to save it in the default location (~/.ssh/id_rsa). You can also set a passphrase for the key.

Copy the Public Key to the EC2 Instance
After generating the key pair, you need to copy the public key (id_rsa.pub) to the new user's ~/.ssh/authorized_keys file on the EC2 instance. On your local machine, use ssh-copy-id or manually copy the key.

To manually copy the key:
First, display the public key using the following command on your local machine:
cat ~/.ssh/id_rsa.pub

On the EC2 instance, still logged in as the new user, open the authorized_keys file:
vi ~/.ssh/authorized_keys

Paste the public key into this file, then save and exit.

Set the Correct Permissions
chmod 600 ~/.ssh/authorized_keys

SSH into the EC2 Instance Using the New User
Now, from your local machine, you can connect to the EC2 instance using the new user and the SSH key:
ssh -i ~/.ssh/id_rsa <new-username>@<EC2-public-IP>

You should now be connected to the instance as the new user with the SSH key.