Connect an already existing EC2 instance with a new ssh key pair - AWS

Question

I have an already running EC2 instance. But the problem is that I lost the old ssh key pair and now I'd like to attach the new ssh key pair to this running instance. Is this possible? If yes how?

Answer 1

yes, this is possible. Follow the below mentioned steps @Hannah:

• Create a new ssh key pair
• Stop the running instance
• Go to Actions -> Instance Settings -> View/change user data
• Add the following script

Content-Type: multipart/mixed; boundary="//"
MIME-Version: 1.0

--//
Content-Type: text/cloud-config; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment; filename="cloud-config.txt"

#cloud-config
cloud_final_modules:
- [users-groups, once]
users:
  - name: username
    ssh-authorized-keys: 
    - ssh-rsa keypair

• Add your username in the username sections and replace the key pair with the new key pair and click on Save.