I'm trying to access my AWS EC2 instance after a long break from using it, and I've run into some trouble. I created an ED25519 key and set the appropriate permissions on both the public and private keys. After importing the public key into a new Ubuntu instance and rebooting it, I attempted to log in using the command `ssh -i keyfile ubuntu@IP`, but I keep getting a 'permission denied (public key)' error.
To troubleshoot, I used the `-v` flag for more detail, and it indicates that the only authentication method is public key, and it's getting denied. I even tried creating a new instance and letting AWS generate the keys for me via the `.pem` file they provide, but the login issues persist. What am I missing?
5 Answers
I don't think AWS has removed any login capabilities. In fact, you've got more options now than ever! Try using Session Manager or EC2 Instance Connect, which can both be more convenient than traditional SSH. They let you connect without needing SSH keys or a public IP, making it easier and potentially more secure.
SSM is definitely the way to go these days. Plus, if you configure it right, you can SSH from your local terminal just like before, really simplifying things. Check out AWS documentation on setting up SSM to enable SSH connections.
Make sure you're using the correct username for your instance. If you're on an Ubuntu AMI, it should be `ubuntu`. For Amazon Linux 2023, use `ec2-user`. Sometimes that simple mistake can lead to the permission denied error!
If you're new to this and facing login issues, take a look into using AWS Systems Manager (SSM). It allows you to access your instances without SSH and can simplify management a lot. You just need to have the right IAM permissions set up. Also, many recent Linux AMIs come with the SSM agent pre-installed, so you can start using it right away!
Don’t get too attached to your instances! If you're worried about losing access, you might want a more robust setup. When you launch a new EC2 instance, let AWS create the key for you. You can use that key with future instances easily. Automate the setup with userdata scripts to install software and services, and remember to tear down instances when you’re done. That way, you keep things efficient!
Yeah, I’ve been tripped up by the username a couple of times too. Definitely worth double-checking!