Add ssh key on AWS EC2 Instance

 

Step 1: Apne system par SSH key generate karo (agar pehle se nahi hai)

Linux/macOS/Git Bash:

ssh-keygen -t ed25519 -C "my-laptop"
--
Ya RSA:
ssh-keygen -t rsa -b 4096
Step 2: Existing .pem se EC2 me login karo
ssh -i mykey.pem ec2-user@YOUR_EC2_IP

Step 3: Public key ko instance me add karo
Apne local system par ye command chalao:
cat ~/.ssh/id_ed25519.pub
Jo output aaye usko copy karo.

Step 4: EC2 instance me authorized_keys file me add karo
Instance ke andar:
mkdir -p ~/.ssh  #This line for first time and first key add kar rhe ho to run karna hai
nano ~/.ssh/authorized_keys
Last line me copied public key paste karo.
Save:

CTRL + O

Enter

CTRL + X
Step 5: Permissions sahi karo, and run these on server(login server)
chmod 700 ~/.ssh
chmod 600 ~/.ssh/authorized_keys

Step 6: New key se test karo, on local
Ab dusre terminal me:
ssh -i ~/.ssh/id_ed25519 ec2-user@YOUR_EC2_IP

Step 6: Agar aap deploy user ke liye key setup kar rahe ho, to instance me login karke ye run karo:
sudo chmod 700 /home/deploy/.ssh
sudo chmod 600 /home/deploy/.ssh/authorized_keys
sudo chown -R deploy:deploy /home/deploy/.ssh

Step 8: Finally added keys on EC2 Instance
Step 8.1 ssh -i ~/.ssh/id_rsa.pub ec2-user@SERVER_IP
---------------------------------------------------------

Alternative (single command)
Direct append bhi kar sakte ho:
cat ~/.ssh/id_ed25519.pub | ssh -i mykey.pem ubuntu@YOUR_EC2_IP "cat >> ~/.ssh/authorized_keys"